Fighter Aircraft Performance, Part I of two, describes the parameters that affect aircraft performance.
For comments please contact me at solo.hermelin@gmail.com.
For more presentations on different subjects visit my website at http://www.solohermelin.com.
Fighter Aircraft Performance, Part II of two, describes the parameters that affect aircraft performance.
For comments please contact me at solo.hermelin@gmail.com.
For more presentations on different subjects visit my website at http://www.solohermelin.com.
Fighter Aircraft Performance, Part II of two, describes the parameters that affect aircraft performance.
For comments please contact me at solo.hermelin@gmail.com.
For more presentations on different subjects visit my website at http://www.solohermelin.com.
Takeoff and Landing | Flight Mechanics | GATE AerospaceAge of Aerospace
For Video Lecture of this presentation: https://youtu.be/ieQYv7p-tnQ
The topics covered in this session are, takeoff performance (ground roll & airborne distance), landing performance (approach distance, flare distance & ground roll). The equations are completely derived from basics and physical significance of the concept is also discussed.
Attention! "Gate Aerospace Engineering aspirants", A virtual guide for gate aerospace engineering is provided in "Age of Aerospace" blog for helping you meticulously prepare for gate examination. Respective notes of individual subjects are provided as 'Embedded Google Docs' which are frequently updated. This comprehensive guide is intended to efficiently serve as an extensive collection of online resources for "GATE Aerospace Engineering" which can be accessed free of cost. Use the following link to access the study material
https://ageofaerospace.blogspot.com/p/gate-aerospace.html
A large number of modern jet aircraft, of all sizes and including Very Light Jets (VLJs)s, routinely cruise at high altitudes.
The record of Accidents and Serious Incidents which have accompanied this increase in high altitude flight has suggested that pilot understanding of the aerodynamic principles which apply to safe high-altitude flight may not always have been sufficient. This applies particularly to attempts to recover from an unexpected loss of control. The subject is introduced in this article and covered in comprehensive detail in the references provided.
From a practical point of view, ‘high altitude’ operations are taken to be those above FL250, which is the altitude at above which aircraft certification requires that a passenger cabin overhead panel oxygen mask drop-down system has to be installed. Above this altitude a number of features begin to take on progressively more significance as altitude continues to increase:
There is a continued reduction in the range of airspeed over which an aircraft remains controllable;
True airspeed (TAS) (and therefore aircraft momentum) increases with altitude. However, the effectiveness of the aerodynamic controls and natural aerodynamic damping are both dependant upon indicated airspeed (IAS) and remain largely unchanged. Therefore, the ability of the aerodynamic flight controls to influence flight path or to recover from an upset is progressively reduced as altitude increases;
In the event of depressurisation, the time of useful consciousness for occupants deprived of oxygen reduces dramatically - see the separate articles on Emergency Depressurisation, and Hypoxia.
At very high altitude, occupants are exposed to slightly increased cosmic radiation. This is covered by the separate article "Cosmic Radiation".
This article focuses on aerodynamics and aircraft handling.
Term Paper Submitted in partial fulfillment of the requirements for the award of the degree of Bachelor of Technology In Aerospace Engineering.
AMITY UNIVERSITY DUBAI
Nomenclature and classification of controls in an airplane (slide # 3-4).
Which are the aerodynamic forces acting on airplane (slide # 5).
Working principle of an airplane (slide # 6).
How an airplane flies (basic motions of an airplane) (slide # 7).
How controls play their roles in these motions (slide # 8-22).
Simulate a flight in Cessna Skyhawk (slide # 23-28).
References and Questions & answers (slide # 30).
Abstract:
Landing gear is one of the critical subsystems of an aircraft. The need to design landing gear with minimum weight, minimum volume, high performance, improved life and reduced life cycle cost have posed many challenges to landing gear designers and practitioners. Further it is essential to reduce the landing gear design and development cycle time while meeting all the regulatory and safety requirements. Many technologies have been developed over the years to meet these challenges in design and development of landing gear. This paper presents a perspective on various stages of landing gear design and development, current technology landscape and how these technologies are helping us to meet the challenges involved in the development of landing gear and how they are going to evolve in future.
NAME : S. Srinivasa Phani Kumar
Branch : MECHANICAL
College : SWARNANDHRA COLLEGE OF ENGINEERING & TECHNOLOGY
Aerodynamics Part II of 3 describes aerodynamics of bodies in supersonic flight.
For comments please contact me at solo.hermelin@gmail.com.
For more presentations on different subjects visit my website at http://www.solohermelin.com.
Takeoff and Landing | Flight Mechanics | GATE AerospaceAge of Aerospace
For Video Lecture of this presentation: https://youtu.be/ieQYv7p-tnQ
The topics covered in this session are, takeoff performance (ground roll & airborne distance), landing performance (approach distance, flare distance & ground roll). The equations are completely derived from basics and physical significance of the concept is also discussed.
Attention! "Gate Aerospace Engineering aspirants", A virtual guide for gate aerospace engineering is provided in "Age of Aerospace" blog for helping you meticulously prepare for gate examination. Respective notes of individual subjects are provided as 'Embedded Google Docs' which are frequently updated. This comprehensive guide is intended to efficiently serve as an extensive collection of online resources for "GATE Aerospace Engineering" which can be accessed free of cost. Use the following link to access the study material
https://ageofaerospace.blogspot.com/p/gate-aerospace.html
A large number of modern jet aircraft, of all sizes and including Very Light Jets (VLJs)s, routinely cruise at high altitudes.
The record of Accidents and Serious Incidents which have accompanied this increase in high altitude flight has suggested that pilot understanding of the aerodynamic principles which apply to safe high-altitude flight may not always have been sufficient. This applies particularly to attempts to recover from an unexpected loss of control. The subject is introduced in this article and covered in comprehensive detail in the references provided.
From a practical point of view, ‘high altitude’ operations are taken to be those above FL250, which is the altitude at above which aircraft certification requires that a passenger cabin overhead panel oxygen mask drop-down system has to be installed. Above this altitude a number of features begin to take on progressively more significance as altitude continues to increase:
There is a continued reduction in the range of airspeed over which an aircraft remains controllable;
True airspeed (TAS) (and therefore aircraft momentum) increases with altitude. However, the effectiveness of the aerodynamic controls and natural aerodynamic damping are both dependant upon indicated airspeed (IAS) and remain largely unchanged. Therefore, the ability of the aerodynamic flight controls to influence flight path or to recover from an upset is progressively reduced as altitude increases;
In the event of depressurisation, the time of useful consciousness for occupants deprived of oxygen reduces dramatically - see the separate articles on Emergency Depressurisation, and Hypoxia.
At very high altitude, occupants are exposed to slightly increased cosmic radiation. This is covered by the separate article "Cosmic Radiation".
This article focuses on aerodynamics and aircraft handling.
Term Paper Submitted in partial fulfillment of the requirements for the award of the degree of Bachelor of Technology In Aerospace Engineering.
AMITY UNIVERSITY DUBAI
Nomenclature and classification of controls in an airplane (slide # 3-4).
Which are the aerodynamic forces acting on airplane (slide # 5).
Working principle of an airplane (slide # 6).
How an airplane flies (basic motions of an airplane) (slide # 7).
How controls play their roles in these motions (slide # 8-22).
Simulate a flight in Cessna Skyhawk (slide # 23-28).
References and Questions & answers (slide # 30).
Abstract:
Landing gear is one of the critical subsystems of an aircraft. The need to design landing gear with minimum weight, minimum volume, high performance, improved life and reduced life cycle cost have posed many challenges to landing gear designers and practitioners. Further it is essential to reduce the landing gear design and development cycle time while meeting all the regulatory and safety requirements. Many technologies have been developed over the years to meet these challenges in design and development of landing gear. This paper presents a perspective on various stages of landing gear design and development, current technology landscape and how these technologies are helping us to meet the challenges involved in the development of landing gear and how they are going to evolve in future.
NAME : S. Srinivasa Phani Kumar
Branch : MECHANICAL
College : SWARNANDHRA COLLEGE OF ENGINEERING & TECHNOLOGY
Aerodynamics Part II of 3 describes aerodynamics of bodies in supersonic flight.
For comments please contact me at solo.hermelin@gmail.com.
For more presentations on different subjects visit my website at http://www.solohermelin.com.
Aerodynamics Part III of 3 describes aerodynamics of wings in supersonic flight.
For comments please contact me at solo.hermelin@gmail.com.
For more presentations on different subjects visit my website at http://www.solohermelin.com.
Air Combat History describes the main air combats and fighter aircraft, from the beginning of aviation. The additional Youtube links are an important part of the presentation. A list of Air-to-Air Missile from different countries. is also given
For comments please contact me at solo.hermelin@gmail.com.
For more presentations visit my website at http://www.solohermelin.com.
Aerodynamics Part I of 3 describes aerodynamics of wings and bodies in subsonic flight.
For comments please contact me at solo.hermelin@gmail.com.
For more presentations on different subjects visit my website at http://www.solohermelin.com.
RADAR - RAdio Detection And Ranging
This is the Part 1 of 2 of RADAR Introduction.
For comments please contact me at solo.hermelin@gmail.com.
For more presentation on different subjects visit my website at http://www.solohermelin.com.
Part of the Figures were not properly downloaded. I recommend viewing the presentation on my website under RADAR Folder.
RADAR - RAdio Detection And Ranging
This is the Part 2 of 2 of RADAR Introduction.
For comments please contact me at solo.hermelin@gmail.com.
For more presentation on different subjects visit my website at http://www.solohermelin.com.
Part of the Figures were not properly downloaded. I recommend viewing the presentation on my website under RADAR Folder.
Estimate the hidden States, Parameters, Signals of a Linear Dynamic Stochastic System from Noisy Measurements. It requires knowledge of probability theory. Presentation at graduate level in math., engineering
For comments please contact me at solo.hermelin@gmail.com.
For more presentations on different subjects visit my website at http://solohermelin.com. Since a few Figure were not downloaded I recommend to see the presentation on my website at RADAR Folder, Tracking subfolder.
This presentation is intended for undergraduate students in physics and engineering.
Please send comments to solo.hermelin@gmail.com.
For more presentations on different subjects please visit my homepage at http://www.solohermelin.com.
This presentation is in the Physics folder.
La razón principal para el estudio de atmósferas planetarias es tratar de entender el origen y evolución de la atmósfera de la tierra. Por supuesto, en el intento de comprender el funcionamiento de nuestro sistema solar o incluso la evolución de la Tierra como un organismo, la atmósfera de la tierra es esencialmente irrelevante, ya que su masa es despreciable.
Aircraft Susceptibility and Vulnerability.
This is from the last presentations from my side. Medical Problems prevent me to continue with new presentations.Please do not contact me.
Describes concepts and development of flying cars and other flying vehicles. Reference are given including to YouTube movies. At the end my view of Main Requirements and the related Design Requirements for a SkyCar are given. The main conclusion is that technologically we are ready to develop and product such a SkyCar in a few years.
For comments please contact me at solo.hermelin@gmail.com.
For more presentations on different subjects visit my website at http://www.solohermelin.com.
This presentation gives example of "Calculus of Variations" problems that can be solved analytical. "Calculus of Variations" presentation is prerequisite to this one.
For comments please contact me at solo.hermelin@gmail.com.
For more presentations on different subjects visit my website at http://www.solohermelin.com.
Describes the mathematics of the Calculus of Variations.
For comments please contact me at solo.hermelin@gmail.com.
For more presentations on different subjects visit my website on http://www.solohermelin.com
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
Introduction:
RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is an important biological process for modulating eukaryotic gene expression.
It is highly conserved process of posttranscriptional gene silencing by which double stranded RNA (dsRNA) causes sequence-specific degradation of mRNA sequences.
dsRNA-induced gene silencing (RNAi) is reported in a wide range of eukaryotes ranging from worms, insects, mammals and plants.
This process mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.
What are small ncRNAs?
micro RNA (miRNA)
short interfering RNA (siRNA)
Properties of small non-coding RNA:
Involved in silencing mRNA transcripts.
Called “small” because they are usually only about 21-24 nucleotides long.
Synthesized by first cutting up longer precursor sequences (like the 61nt one that Lee discovered).
Silence an mRNA by base pairing with some sequence on the mRNA.
Discovery of siRNA?
The first small RNA:
In 1993 Rosalind Lee (Victor Ambros lab) was studying a non- coding gene in C. elegans, lin-4, that was involved in silencing of another gene, lin-14, at the appropriate time in the
development of the worm C. elegans.
Two small transcripts of lin-4 (22nt and 61nt) were found to be complementary to a sequence in the 3' UTR of lin-14.
Because lin-4 encoded no protein, she deduced that it must be these transcripts that are causing the silencing by RNA-RNA interactions.
Types of RNAi ( non coding RNA)
MiRNA
Length (23-25 nt)
Trans acting
Binds with target MRNA in mismatch
Translation inhibition
Si RNA
Length 21 nt.
Cis acting
Bind with target Mrna in perfect complementary sequence
Piwi-RNA
Length ; 25 to 36 nt.
Expressed in Germ Cells
Regulates trnasposomes activity
MECHANISM OF RNAI:
First the double-stranded RNA teams up with a protein complex named Dicer, which cuts the long RNA into short pieces.
Then another protein complex called RISC (RNA-induced silencing complex) discards one of the two RNA strands.
The RISC-docked, single-stranded RNA then pairs with the homologous mRNA and destroys it.
THE RISC COMPLEX:
RISC is large(>500kD) RNA multi- protein Binding complex which triggers MRNA degradation in response to MRNA
Unwinding of double stranded Si RNA by ATP independent Helicase
Active component of RISC is Ago proteins( ENDONUCLEASE) which cleave target MRNA.
DICER: endonuclease (RNase Family III)
Argonaute: Central Component of the RNA-Induced Silencing Complex (RISC)
One strand of the dsRNA produced by Dicer is retained in the RISC complex in association with Argonaute
ARGONAUTE PROTEIN :
1.PAZ(PIWI/Argonaute/ Zwille)- Recognition of target MRNA
2.PIWI (p-element induced wimpy Testis)- breaks Phosphodiester bond of mRNA.)RNAse H activity.
MiRNA:
The Double-stranded RNAs are naturally produced in eukaryotic cells during development, and they have a key role in regulating gene expression .
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
Richard's entangled aventures in wonderlandRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
Richard's aventures in two entangled wonderlandsRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
13 fixed wing fighter aircraft- flight performance - i
1. Fixed Wing Fighter Aircraft
Flight Performance
Part I
SOLO HERMELIN
Updated: 04.12.12
28.02.15
1
http://www.solohermelin.com
2. Table of Content
SOLO
Fixed Wing Aircraft Flight Performance
2
Introduction to Fixed Wing Aircraft Performance
Earth Atmosphere
Aerodynamics
Mach Number
Shock & Expansion Waves
Reynolds Number and Boundary Layer
Knudsen Number
Flight Instruments
Aerodynamic Forces
Aerodynamic Drag
Lift and Drag Forces
Wing Parameters
Specific Stabilizer/Tail Configurations
3. Table of Content (continue – 1)
SOLO
3
Specific Energy
Aircraft Propulsion Systems
Aircraft Propellers
Aircraft Turbo Engines
Afterburner
Thrust Reversal Operation
Aircraft Propulsion Summary
Vertical Take off and Landing - VTOL
Engine Control System
Aircraft Flight Control
Aircraft Equations of Motion
Aerodynamic Forces (Vectorial)
Three Degrees of Freedom Model in Earth Atmosphere
Comparison of Fighter Aircraft Propulsion Systems
Fixed Wing Fighter Aircraft Flight Performance
4. Table of Content (continue – 2)
SOLO
Fixed Wing Fighter Aircraft Flight Performance
4
Parameters defining Aircraft Performance
Takeoff (no VSTOL capabilities)
Landing (no VSTOL capabilities)
Climbing Aircraft Performance
Gliding Flight
Level Flight
Steady Climb (V, γ = constant)
Optimum Climbing Trajectories using Energy State
Approximation (ESA)
Minimum Fuel-to- Climb Trajectories using Energy State
Approximation (ESA)
Maximum Range during Glide using Energy State
Approximation (ESA)
Aircraft Turn Performance
Maneuvering Envelope, V – n Diagram
F
i
x
e
d
W
i
n
g
P
a
r
t
I
I
5. Table of Content (continue – 3)
SOLO
Fixed Wing Fighter Aircraft Flight Performance
5
Air-to-Air Combat
Energy–Maneuverability Theory
Supermaneuverability
Constraint Analysis
Aircraft Combat Performance Comparison
References
F
i
x
e
d
W
i
n
g
P
a
r
t
I
I
6. SOLO
This Presentation is about Fixed Wing Aircraft Flight Performance.
The Fixed Wing Aircraft are
•Commercial/Transport Aircraft (Passenger and/or Cargo)
•Fighter Aircraft
Fixed Wing Fighter Aircraft Flight Performance
Return to Table of Content
7. 7
Percent composition of dry atmosphere, by volume
ppmv: parts per million by volume
Gas Volume
Nitrogen (N2) 78.084%
Oxygen (O2) 20.946%
Argon (Ar) 0.9340%
Carbon dioxide (CO2) 365 ppmv
Neon (Ne) 18.18 ppmv
Helium (He) 5.24 ppmv
Methane (CH4) 1.745 ppmv
Krypton (Kr) 1.14 ppmv
Hydrogen (H2) 0.55 ppmv
Not included in above dry atmosphere:
Water vapor (highly variable) typically 1%
Gas Volume
nitrous oxide 0.5 ppmv
xenon 0.09 ppmv
ozone
0.0 to 0.07 ppmv (0.0 to 0.02
ppmv in winter)
nitrogen dioxide 0.02 ppmv
iodine 0.01 ppmv
carbon monoxide trace
ammonia trace
•The mean molecular mass of air is 28.97 g/mol.
Minor components of air not listed above include:
Composition of Earth's atmosphere. The lower pie
represents the trace gases which together compose
0.039% of the atmosphere. Values normalized for
illustration. The numbers are from a variety of
years (mainly 1987, with CO2 and methane from
2009) and do not represent any single source
Earth AtmosphereSOLO
9. The basic variables representing the thermodynamics state of the gas are the Density, ρ,
Temperature, T and Pressure, p.
SOLO
9
The Density, ρ, is defined as the mass, m, per unit volume, v, and has units of kg/m3
.
v
m
v ∆
∆
=
→∆ 0
limρ
The Temperature, T, with units in degrees Kelvin ( ͦ K). Is a measure of the average kinetic
energy of gas particles.
The Pressure, p, exerted by a gas on a solid surface is defined as the rate of change of normal
momentum of the gas particles striking per unit area.
It has units of N/m2
. Other pressure units are millibar (mbar), Pascal (Pa), millimeter of mercury
height (mHg)
S
f
p n
S ∆
∆
=
→∆ 0
lim
kPamNbar 100/101 25
==
( ) mmHginHgkPamkNmbar 00.7609213.29/325.10125.1013 2
===
The Atmospheric Pressure at Sea Level is:
Earth Atmosphere
10. 10
Physical Foundations of Atmospheric Model
The Atmospheric Model contains the values of
Density, Temperature and Pressure as function
of Altitude.
Atmospheric Equilibrium (Barometric) Equation
In figure we see an atmospheric
element under equilibrium under
pressure and gravitational forces
( )[ ] 0=⋅+−+⋅⋅⋅− APdPPHdAg gρ
or
( ) gg HdHgPd ⋅⋅=− ρ
In addition, we assume the atmosphere to be a thermodynamic fluid. At altitude
bellow 100 km we assume the Equation of an Ideal Gas
where
V – is the volume of the gas
N – is the number of moles in the volume V
m – the mass of gas in the volume V
R* - Universal gas constant
TRNVP ⋅⋅=⋅ *
V
m
M
m
N == ρ&
MTRP /*
⋅⋅= ρ
Earth AtmosphereSOLO
12. We must make a distinction between:
- Kinetic Temperature (T): measures the molecular kinetic energy
and for all practical purposes is identical to thermometer
measurements at low altitudes.
- Molecular Temperature (TM): assumes (not true) that the
Molecular Weight at any altitude (M) remains constant and is
given by sea-level value (M0)
SOLO
12
T
M
M
TM ⋅= 0
To simplify the computation let introduce:
- Geopotential Altitude H
- Geometric Altitude Hg
Newton Gravitational Law implies: ( )
2
0
+
⋅=
gE
E
g
HR
R
gHg
The Barometric Equation is ( ) gg HdHgPd ⋅⋅=− ρ
The Geopotential Equation is defined as HdgPd ⋅⋅=− 0ρ
This means that g
gE
E
g Hd
HR
R
Hd
g
g
Hd ⋅
+
=⋅=
2
0
Integrating we obtain g
gE
E
H
HR
R
H ⋅
+
=
Earth Atmosphere
13. 13
Atmospheric Constants
Definition Symbol Value Units
Sea-level pressure P0 1.013250 x 105
N/m2
Sea-level temperature T0 288.15 ͦ K
Sea-level density ρ0 1.225 kg/m3
Avogadro’s Number Na 6.0220978 x 1023
/kg-mole
Universal Gas Constant R* 8.31432 x 103
J/kg-mole -ͦ K
Gas constant (air) Ra=R*/M0 287.0 J/kg--ͦ
K
Adiabatic polytropic constant γ 1.405
Sea-level molecular weight M0 28.96643
Sea-level gravity acceleration g0 9.80665 m/s2
Radius of Earth (Equator) Re 6.3781 x 106
m
Thermal Constant β 1.458 x 10-6
Kg/(m-s-ͦ K1/2)
Sutherland’s Constant S 110.4 ͦ K
Collision diameter σ 3.65 x 10-10
m
Earth AtmosphereSOLO
14. 14
Physical Foundations of Atmospheric Model
Atmospheric Equilibrium Equation
HdgPd ⋅⋅=− 0ρ
At altitude bellow 100 km we assume t6he Equation
of an Ideal Gas
TRMTRP a
MRR
a
aa
⋅⋅=⋅⋅=
=
ρρ
/
*
*
/
Hd
TR
g
P
Pd
a
⋅=− 0
Combining those two equations we obtain
Assume that T = T (H), i.e. function of Geopotential Altitude only.
The Standard Model defines the variation of T with altitude based on experimental data.
The 1976 Standard Model for altitudes between 0.0 to 86.0 km is divided in 7 layers. In each
layer dT/d H = Lapse-rate is constant.
Earth AtmosphereSOLO
15. 15
Layer
Index
Geopotential
Altitude Z,
km
Geometric
Altitude Z;
km
Molecular
Temperature T,
ͦ K
0 0.0 0.0 288.150
1 11.0 11.0102 216.650
2 20.0 20.0631 216.650
3 32.0 32.1619 228.650
4 47.0 47.3501 270.650
5 51.0 51.4125 270.650
6 71.0 71.8020 214.650
7 84.8420 86.0 186.946
1976 Standard Atmosphere : Seven-Layer Atmosphere
Lapse Rate
Lh;
ͦ K/km
-6.3
0.0
+1.0
+2.8
0.0
-2.8
-2.0
Earth AtmosphereSOLO
16. 16
Physical Foundations of Atmospheric Model
• Troposphere (0.0 km to 11.0 km).
We have ρ (6.7 km)/ρ (0) = 1/e=0.3679, meaning that 63% of the atmosphere
lies below an altitude of 6.7 km.
( )
Hd
HLTR
g
Hd
TR
g
P
Pd
aa
⋅
⋅+
=⋅=−
0
00
kmKLHLTT /3.60
−=⋅+=
Integrating this equation we obtain
( )∫∫ ⋅
⋅+
=−
H
a
P
P
Hd
HLTR
g
P
PdS
S 0 0
0 1
0
( )
0
00
lnln
0
T
HLT
RL
g
P
P
aS
S ⋅+
⋅
⋅
−=
Hence
aRL
g
SS H
T
L
PP
⋅
−
⋅+⋅=
0
0
0
1
and
−
⋅=
⋅
1
0
0
0
g
RL
S
S
a
P
P
L
T
H
Earth AtmosphereSOLO
Stratosphere
Troposphere
17. 17
Physical Foundations of Atmospheric Model
Hd
TR
g
P
Pd
Ta
⋅=− *
0
Integrating this equation we obtain
( )T
TaS
S
HH
TR
g
P
P
T
−⋅
⋅
−= *
0
ln
Hence
( )T
Ta
T
HH
TR
g
SS ePP
−⋅
⋅
−
⋅=
*
0
and
S
STTa
T
P
P
g
TR
HH ln
0
*
⋅
⋅
+=
∫∫ =−
H
HTa
P
P T
S
TS
Hd
TR
g
P
Pd
*
0
• Stratosphere Region (HT=11.0 km to 20.0 km).
Temperature T = 216.65 ͦ K = TT* is constant (isothermal layer), PST=22632
Pa
Earth AtmosphereSOLO
Stratosphere
Troposphere
18. 18
Physical Foundations of Atmospheric Model
( )[ ] Hd
HHLTR
g
Hd
TR
g
P
Pd
SSTaa
⋅
−⋅+⋅
=⋅=− *
00
( ) ( ) PaPHPkmKLHHLTT SSSSSST 5474.9,/0.1
*
===−⋅−=
Integrating this equation we obtain
( )[ ]∫∫ ⋅
−⋅+
=−
H
H SSTa
P
P S
S
SS
Hd
HHLTR
g
P
Pd
*
0 1
( )[ ]
*
*
0
lnln
T
ST
aSSS
S
T
HHLT
RL
g
P
P −⋅+
⋅
⋅
=
Hence ( )
aRL
g
S
T
S
SSS HH
T
L
PP
⋅
−
−⋅+⋅=
0
*
1
and
−
⋅+=
⋅
1
0
* g
RL
SS
S
S
T
S
aS
P
P
L
T
HH
Stratosphere Region (HS=20.0 km to 32.0 km).
Stratosphere
Troposphere
Earth AtmosphereSOLO
19. 19
1962 Standard Atmosphere from 86 km to 700 km
Layer Index Geometric
Altitude
km
Molecular
Temperature
,
K
Kinetic
Temperature
K
Molecular
Weight
Lapse
Rate
K/km
7 86.0 186.946 186.946 28.9644 +1.6481
8 100.0 210.65 210.02 28.88 +5.0
9 110.0 260.65 257.00 28.56 +10.0
10 120.0 360.65 349.49 28.08 +20.0
11 150.0 960.65 892.79 26.92 +15.0
12 160.0 1110.65 1022.20 26.66 +10.0
13 170.0 1210.65 1103.40 26.49 +7.0
14 190.0 1350.65 1205.40 25.85 +5.0
15 230.0 1550.65 132230 24.70 +4.0
16 300.0 1830.65 1432.10 22.65 +3.3
17 400.0 2160.65 1487.40 19.94 +2.6
18 500.0 2420.65 1506.10 16.84 +1.7
19 600.0 2590.65 1506.10 16.84 +1.1
20 700.0 2700.65 1507.60 16.70
Earth AtmosphereSOLO
20. 20
1976 Standard Atmosphere from 86 km to 1000 km
Geometric Altitude Range: from 86.0 km to 91.0 km (index 7 – 8)
78
/0.0
TT
kmK
Zd
Td
=
=
Geometric Altitude Range: from 91.0 km to 110.0 km (index 8 – 9)
2/12
8
2
8
2/12
8
1
1
−
−
−
−
⋅−=
−
−⋅+=
a
ZZ
a
ZZ
a
A
Zd
Td
a
ZZ
ATT C
kma
KA
KTC
9429.19
3232.76
1902.263
−=
−=
=
Geometric Altitude Range: from 110.0 km to 120.0 km (index 9 – 10)
( )
kmK
Zd
Td
ZZLTT Z
/0.12
99
+=
−⋅+=
Geometric Altitude Range: from 120.0 km to 1000.0 km (index 10 – 11)
( ) ( )
( )
( )
+
+
⋅−=
+
+
⋅−⋅=
⋅−⋅−−=
∞
∞∞
ZR
ZR
ZZ
kmK
ZR
ZR
TT
Zd
Td
TTTT
E
E
E
E
10
10
10
10
10
/
exp
ξ
λ
ξλ
KT
kmR
km
E
1000
10356766.6
/01875.0
3
=
×=
=
∞
λ
Earth AtmosphereSOLO
21. 21
Sea Level Values
Pressure p0 = 101,325 N/m2
Density ρ0 = 1.225 kg/m3
Temperature = 288.15 ͦ K (15 ͦ C)
Acceleration of gravity g0 = 9.807 m/sec2
Speed of Sound a0 = 340.294 m/sec
Earth AtmosphereSOLO
Return to Table of Content
23. 23
SOLO
Dimensionless Equations
Dimensionless Field Equations
(C.M.): ( ) 0
~~~~
=⋅∇+ u
t
ρ
∂
ρ∂
( ) ( )u
R
u
R
pG
F
uu
t
u
eer
~~~~1
3
4~~~~1~~~~1~~~
~
~
~
2
⋅∇∇+×∇×∇−∇−=
∇⋅+ µµρ
∂
∂
ρ(C.L.M.):
( ) ( )Tk
PRt
Q
uG
F
u
t
p
Hu
t
H
rer
∇⋅∇−+⋅+⋅⋅∇+=
∇⋅+
∂
∂ 11
~
~
~~~1~~~
~
~~~~
~
~
~
2
∂
∂
ρτ
∂
∂
ρ
(C.E.):
Reynolds:
0
000
µ
ρ lU
Re = Prandtl:
0
0
k
C
P p
r
µ
= Froude:
0
0
gl
U
Fr =
0/~ ρρρ = 0/
~
Uuu = gGG /
~
= ( )2
00/~ Upp ρ=
0/
~
lUtt =
2
0/
~
UCTT p=( )2
00/~ Uρττ =
2
0/
~
UHH =
2
0/
~
Uhh =
2
0/~ Uee = ( )2
00/~ Uqq ρ= ( )2
/
~
UQQ =
∇=∇ 0
~
l
0/~ ρρρ = 0/
~
Uuu = gGG /
~
= ( )2
00/~ Upp ρ=
0/
~
lUtt =
2
0/
~
UCTT p=( )2
00/~ Uρττ =
2
0/
~
UHH =
2
0/
~
Uhh =
2
0/~ Uee = ( )2
00/~ Uqq ρ= ( )2
/
~
UQQ =
∇=∇ 0
~
l
0/~ µµµ =
0/
~
kkk =
Dimensionless Variables are:
Reference Quantities: ρ0(density), U0(velocity), l0 (length), g (gravity), μ0 (viscosity),
k0 (Fourier Constant), λ0 (mean free path)
0/
~
λλλ =
Knudsen
l
Kn
0
0
:
λ
=
AERODYNAMICS
Return to Table of Content
24. 24
SOLO
Mach Number
Mach number (M or Ma) / is a dimensionless quantity representing
the ratio of speed of an object moving through a fluid and the local
speed of sound.
• M is the Mach number,
• U0 is the velocity of the source relative to the medium, and
• a0 is the speed of sound
Mach:
0
0
a
U
M =
The Mach number is named after Austrian physicist and philosopher
Ernst Mach, a designation proposed by aeronautical engineer Jakob
Ackeret.
Ernst Mach
(1838–1916)
Jakob Ackeret
(1898–1981)
m
Tk
Mo
TR
a Bγγ
==0
• R is the Universal gas constant, (in SI, 8.314 47215 J K−1
mol−1
), [M1
L2
T−2
θ−1
'mol'−1
]
• γ is the rate of specific heat constants Cp/Cv and is dimensionless
γair = 1.4.
• T is the thermodynamic temperature [θ1
]
• Mo is the molar mass, [M1
'mol'−1
]
• m is the molecular mass, [M1
]
AERODYNAMICS
25. 25
SOLO
Mach Number – Flow Regimes
Regime Mach mph km/h m/s General plane characteristics
Subsonic <0.8 <610 <980 <270
Most often propeller-driven and commercial turbofan aircraft with
high aspect-ratio (slender) wings, and rounded features like the
nose and leading edges.
Transonic 0.8-1.2
610-
915
980-1,470 270-410
Transonic aircraft nearly always have swept wings, delaying drag-
divergence, and often feature design adhering to the principles of
the Whitcomb Area rule.
Supersonic 1.2–5.0
915-
3,840
1,470–
6,150
410–1,710
Aircraft designed to fly at supersonic speeds show large differences
in their aerodynamic design because of the radical differences in the
behavior of flows above Mach 1. Sharp edges, thin airfoil-sections,
and all-moving tailplane/canards are common. Modern combat
aircraft must compromise in order to maintain low-speed handling;
"true" supersonic designs include the F-104 Starfighter, SR-71
Blackbird and BAC/Aérospatiale Concorde.
Hypersonic 5.0–10.0
3,840–
7,680
6,150–
12,300
1,710–
3,415
Cooled nickel-titanium skin; highly integrated (due to domination
of interference effects: non-linear behaviour means that
superposition of results for separate components is invalid), small
wings, such as those on the X-51A Waverider
High-
hypersonic
10.0–25.0
7,680–
16,250
12,300–
30,740
3,415–
8,465
Thermal control becomes a dominant design consideration.
Structure must either be designed to operate hot, or be protected by
special silicate tiles or similar. Chemically reacting flow can also
cause corrosion of the vehicle's skin, with free-atomic oxygen
featuring in very high-speed flows. Hypersonic designs are often
forced into blunt configurations because of the aerodynamic heating
rising with a reduced radius of curvature.
Re-entry
speeds
>25.0
>16,25
0
>30,740 >8,465 Ablative heat shield; small or no wings; blunt shape
AERODYNAMICS
27. 27
SOLO
- when the source moves at subsonic velocity V < a, it will stay inside the
family of spherical sound waves.
a
V
M
M
=
= −
&
1
sin 1
µ
Disturbances in a fluid propagate by molecular collision, at the sped of sound a,
along a spherical surface centered at the disturbances source position.
The source of disturbances moves with the velocity V.
- when the source moves at supersonic velocity V > a, it will stay outside the
family of spherical sound waves. These wave fronts form a disturbance
envelope given by two lines tangent to the family of spherical sound waves.
Those lines are called Mach waves, and form an angle μ with the disturbance
source velocity:
SHOCK & EXPANSION WAVES
AERODYNAMICS
29. 29
SOLO
When a supersonic flow encounters a boundary the following will happen:
When a flow encounters a boundary it must satisfy the boundary conditions,
meaning that the flow must be parallel to the surface at the boundary.
- when the supersonic flow, in order to remain parallel to the boundary surface,
must “turn into itself” a Oblique Shock will occur. After the shock wave the
pressure, temperature and density will increase.
The Mach number of the flow will decrease after the shock wave.
SHOCK & EXPANSION WAVES
- when the supersonic flow, in order to remain parallel to the boundary surface,
must “turn away from itself” an Expansion wave will occur. In this case the
pressure, temperature and density will decrease.
The Mach number of the flow will increase after the expansion wave.
Return to Table of Content
AERODYNAMICS
30. 30
SHOCK WAVES
SOLO
A shock wave occurs when a supersonic flow decelerates in response to a sharp
increase in pressure (supersonic compression) or when a supersonic flow encounters
a sudden, compressive change in direction (the presence of an obstacle).
For the flow conditions where the gas is a continuum, the shock wave is a narrow region
(on the order of several molecular mean free paths thick, ~ 6 x 10-6
cm) across which is
an almost instantaneous change in the values of the flow parameters.
Shock Wave Definition (from John J. Bertin/ Michael L. Smith,
“Aerodynamics for Engineers”, Prentice Hall, 1979, pp.254-255)
When the shock wave is normal to the streamlines it is called a Normal Shock Wave,
otherwise it is an Oblique Shock Wave.
The difference between a shock wave and a Mach wave is that:
- A Mach wave represents a surface across which some derivative of the flow variables
(such as the thermodynamic properties of the fluid and the flow velocity) may be
discontinuous while the variables themselves are continuous. For this reason we call
it a weak shock.
- A shock wave represents a surface across which the thermodynamic properties and the
flow velocity are essentially discontinuous. For this reason it is called a strong shock.
AERODYNAMICS
31. 31
Movement of Shocks with Increasing Mach Number
<<<<<<< MMMMMMMM
SOLO AERODYNAMICS
Return to Table of Content
32. 32
where
ρ0 = air density
U0 = true speed
l 0= characteristic length
μ0 = absolute (dynamic) viscosity
υ0 = kinematic viscosity
NumberReynolds:Re
0
00
0
000
0
0
0
υµ
ρ ρ
µ
υ
lUlU
=
==
Osborne Reynolds
(1842 –1912)
It was observed by Reynolds in 1884 that a Fluid Flow changes from Laminar to
Turbulent at approximately the same value of the dimensionless ratio (ρ V l/ μ) where l is
the Characteristic Length for the object in the Flow. This ratio is called the Reynolds
number, and is the governing parameter for Viscous Flow.
Reynolds Number and Boundary Layer
SOLO 1884AERODYNAMICS
33. 33
Boundary Layer
SOLO
1904AERODYNAMICS
Ludwig Prandtl
(1875 – 1953)
In 1904 at the Third Mathematical Congress, held at
Heidelberg, Germany, Ludwig Prandtl (29 years old) introduced
the concept of Boundary Layer.
He theorized that the fluid friction was the cause of the fluid
adjacent to surface to stick to surface – no slip condition, zero
local velocity, at the surface – and the frictional effects were
experienced only in the boundary layer a thin region near the
surface. Outside the boundary layer the flow may be considered
as inviscid (frictionless) flow.
In the Boundary Layer on can calculate the
•Boundary Layer width
•Dynamic friction coefficient μ
•Friction Drag Coefficient CDf
34. 34
The flow within the Boundary Layer can be of two types:
•The first one is Laminar Flow, consists of layers of flow sliding one over other in a
regular fashion without mixing.
•The second one is called Turbulent Flow and consists of particles of flow that
moves in a random and irregular fashion with no clear individual path, In
specifying the velocity profile within a Boundary Layer, one must look at the
mean velocity distribution measured over a long period of time.
There is usually a transition region between this two types of Boundary-Layer Flow
SOLO
AERODYNAMICS
35. 35
Normalized Velocity profiles within a Boundary-Layer, comparison between
Laminar and Turbulent Flow.
SOLO
AERODYNAMICS
Boundary-Layer
36. 36
Flow Characteristics around a Cylindrical Body
as a Function of Reynolds Number (Viscosity)
AERODYNAMICS
SOLO
Return to Table of Content
37. 37
SOLO
Knudsen number (Kn) is a dimensionless number defined as the
ratio of the molecular mean free path length to a representative
physical length scale. This length scale could be, for example, the
radius of the body in a fluid. The number is named after Danish
physicist Martin Knudsen.
Knudsen
l
Kn
0
0
:
λ
= Martin Knudsen
(1871–1949).
For a Boltzmann gas, the mean free path may be readily calculated as:
• kB is the Boltzmann constant (1.3806504(24) × 10−23
J/K in SI units), [M1
L2
T−2
θ−1
]
p
TkB
20
2 σπ
λ =
• T is the thermodynamic temperature [θ1
]
λ0 = mean free path [L1
]
Knudsen Number
l0 = representative physical length scale [L1
].
• σ is the particle hard shell diameter, [L1
]
• p is the total pressure, [M1
L−1
T−2
].
See “Kinetic Theory of Gases” Presentation
For particle dynamics in the atmosphere and assuming standard atmosphere pressure i.e.
25 °C and 1 atm, we have λ0 ≈ 8x10-8
m.
AERODYNAMICS
38. 38
SOLO
Martin Knudsen
(1871–1949).
Knudsen Number (continue – 1)
Relationship to Mach and Reynolds numbers
Dynamic viscosity,
Average molecule speed (from Maxwell–Boltzmann distribution),
thus the mean free path,
where
• kB is the Boltzmann constant (1.3806504(24) × 10−23
J/K in SI units), [M1
L2
T−2
θ−1
]
• T is the thermodynamic temperature [θ1
]
• ĉ is the average molecular speed from the Maxwell–Boltzmann distribution, [L1
T−1
]
• μ is the dynamic viscosity, [M1
L−1
T−1
]
• m is the molecular mass, [M1
]
• ρ is the density, [M1
L−3
].
0
2
1
λρµ c=
m
Tk
c B
π
8
=
Tk
m
B2
0
π
ρ
µ
λ =
AERODYNAMICS
39. 39
SOLO
Martin Knudsen
(1871–1949).
Knudsen Number (continue – 2)
Relationship to Mach and Reynolds numbers (continue – 1)
The dimensionless Reynolds number can be written:
Dividing the Mach number by the Reynolds number,
and by multiplying by
yields the Knudsen number.
The Mach, Reynolds and Knudsen numbers are therefore related by:
Reynolds:Re
0
000
µ
ρ lU
=
Tk
m
lmTklallU
aUM
BB
γρ
µ
γρ
µ
ρ
µ
µρ 00
0
00
0
000
0
0000
00
//
/
Re
====
Kn
Tk
m
lTk
m
l BB
==
22 00
0
00
0 π
ρ
µπγ
γρ
µ
2Re
πγM
Kn =
AERODYNAMICS
40. 40
SOLO
Knudsen Number (continue – 3)
Relationship to Mach and Reynolds numbers (continue –2)
According to the Knudsen Number the Gas Flow can be divided in three regions:
1.Free Molecular Flow (Kn >> 1): M/Re > 3
molecule-interface interaction negligible between incident and reflected particles
2.Transition (from molecular to continuum flow) regime: 3 > M/Re and
M/(Re)1/2
> 0.01 (Re >> 1). Both intermolecular and molecule-surface collision are
important.
3.Continuum Flow (Kn << 1): 0.01 > M/(Re)1/2
. Dominated by intermolecular
collisions.
2Re
πγM
Kn =
AERODYNAMICS
41. SOLO
Knudsen Number (continue – 4)
Inviscid
Limit Free
Molecular
LimitKnudsen Number
Boltzman Equation
Collisionless
Boltzman
Equation
Discrete
Particle
model
Euler
Equation
Navier-Stokes
Equation
Continuum
model
Conservation Equation
do not form a closed set
Validity of conventional mathematical models as a function of local
Knudsen Number
A higher Knudsen Number indicates larger mean free path λ, or the particular nature
of the Fluid, meaning that Boltzmann Equations must be employed.
Lower Knudsen Number means small free path, i.e. the flow acts as a continuum,
and Navier-Stokes Equations must be used.
Knudsen
l
Kn
0
0
:
λ
=
AERODYNAMICS
Return to Table of Content
42. 42
The true airspeed (TAS; also KTAS, for knots true airspeed) of an aircraft is
the speed of the aircraft relative to the air mass in which it is flying.
True Airspeed
TAS can be calculated as a function of Mach number and static air temperature:
where
a0 is the speed of sound at standard sea level (661.47 knots)
M is Mach number,
T is static air temperature in kelvin,
T0 is the temperature at standard sea level (288.15ºK)
0
0
T
T
MaTAS =
qc is impact pressure
P is static pressure
−
+= 11
5 7
2
0
0
P
q
T
T
aTAS c
Flight Instruments
44. SOLO
44
Flight Instruments
Airspeed Indicators
2
2
1
vpp StatTotal ⋅+= ρ
The airspeed directly given by the differential pressure is called
Indicated Airspeed (IAS). This indication is subject to positioning errors of the pitot
and static probes, airplane altitude and instrument systematic defects.
The airspeed corrected for those errors is called Calibrated Airspeed (CAS).
Depending on altitude, the critic airspeeds for maneuver, flap operation etc. change
because the aerodynamic forces are function of air density. An equivalent airspeed
VE (EAS) is defined as follows:
0ρ
ρ
VVE =
V – True Airspeed
ρ – Air Density
ρ0 – Air Density at Sea Level
55. ( )
[ ] [ ]( )∫
∫
∞∞
=
−−−=
−=′
Edge
Trailing
Edge
Leading
sideuppersidelower
cos
Edge
Trailing
Edge
Leading
sideuppersidelower
pp
cospcosp
dxpp
dsL
sdxd
USLS
θ
θθ
Divide left and right sides of the first equation by cV 2
2
1
∞ρ
∫
−
−
−
=
′
∞
∞
∞
∞
∞
Edge
Trailing
Edge
Leading
upperlower
c
x
d
V
pp
V
pp
cV
L
222
2
1
2
1
2
1
ρρρ
We get:
Relationship between Lift and Pressure on Airfoil
Lower
Surface
Upper
Surface
( )∫ −=−
Edge
Trailing
Edge
Leading
sideuppersidelower sinpsinp dsD USLS θθ
Lift – Aerodynamic component normal to V
Drag – Aerodynamic component opposite to V
SOLO AERODYNAMICS
Aerodynamic Forces
56. From the previous slide,
∫
−
−
−
=
′
∞
∞
∞
∞
∞
Edge
Trailing
Edge
Leading
upperlower
c
x
d
V
pp
V
pp
cV
L
222
2
1
2
1
2
1
ρρρ
The left side was previously defined as the sectional lift coefficient Cl.
The pressure coefficient is defined as:
2
2
1
∞
∞−
=
V
pp
Cp
ρ
Thus,
( )∫ −=
edge
Trailing
edge
Leading
upperplowerpl
c
x
dCCC ,,
Lower
Surface
Upper
Surface
Relationship between Lift and Pressure on Airfoil (continue – 1)
SOLO AERODYNAMICS
Aerodynamic Forces
57. 57
SOLO
Velocity Field
Sum of the elementary Forces on the Body
Lift as the Sum of the elementary Forces on the Body
AERODYNAMICS
Aerodynamic Forces
58. 58
SOLO
Lift and Drag Coefficients
AERODYNAMICS
Subsonic Speeds
np
α−
Upper
xd
yd
∞U
Upper
xd
yd
∞p∞p α
0,,
2
0 2
0
D
TurbulentforMore
LaminarforLess
dragFriction
fD
TurbulentforLess
LaminarforMore
dragPressure
pDD
stall
a
L
CCCC
aC
=+=
<==
=
αααπα
π
Subsonic Incompressible Flow (ρ∞ = const.) about Wings of Finite Span (AR < ∞)
Subsonic Incompressible Flow (ρ∞ = const.) about Wings of Infinite Span (AR → ∞)
( )
−=−=
ARe
C
C L
i
a
L
π
απααπ 22
0
ARe
C
be
SC
V
w L
SbAR
Li
i
ππ
α
/
2
2
=
===
α
π
α
π
ARe
a
a
ARe
CL
0
0
1
2
1
2
+
=
+
=
ARe
C
C L
Di
π
2
=
AR
C
CCCCC L
D
drag
induced
D
drag
friction
fD
drag
pressure
pDD i
π
2
0,, +=++=
e – span efficiency factor
Aerodynamic Forces
Return to Table of Content
62. 62N.X. Vinh, “Flight Mechanics of High-Performance Aircraft”, Cambridge University
Press, 1993
α =0 – corresponds to CL=0.
α0 – minimize CD.
α1 – minimize the ratio CD/CL
1/2
.
α2 – minimize the ratio CD/CL
2/3
.
α*
– minimize the ratio CD/CL.
α3 – minimize the ratio CD/CL
3/2
.
αmax – maximum CL.
A Realistic Drag Polar
SOLO AERODYNAMICS
Aerodynamic Drag
63. 63N.X. Vinh, “Flight Mechanics of High-Performance Aircraft”, Cambridge University
Press, 1993
Parabolic Drag Polar of a typical High Subsonic Aircraft
at different Mach Numbers
SOLO AERODYNAMICS
Aerodynamic Drag
64. 64N.X. Vinh, “Flight Mechanics of High-Performance Aircraft”, Cambridge University
Press, 1993
Variation of CD0 (M) for a supersonic
aircraft
Variation of aerodynamic characteristic
for a typical subsonic transport aircraft
Variation of aerodynamic characteristic
for a typical supersonic fighter aircraft
SOLO AERODYNAMICS
Aerodynamic Drag
65. 65
Movement of Shocks with Increasing Mach Number
The Mach Number at witch M=1 appears
on the Airfoil Upper Surface is called the
Critical Mach Number for this Airfoil.
The Critical Mach Number can be
calculated as follows. Assuming an
isentropic flow through the flow-field we
have
( )1/
2
2
2
1
1
2
1
1
−
∞
∞
−
+
−
+
=
γγ
γ
γ
A
A
M
M
p
p
p∞, M∞ - Pressure and Mach Number upstream the Airfoil
pA, MA- Pressure and Mach Number at a point A on the Airfoil
Critical Mach Number
The Pressure Coefficient Cp is computed using
( )
−
−
+
−
+
=
−=
−
∞
∞∞∞
1
2
1
1
2
1
1
2
1
2
1/
2
2
γγ
γ
γ
γγ
A
A
pA
M
M
Mp
p
M
C
Definition of Critical Mach
Number.
Point A is the location of
minimum pressure on the
top surface of the Airfoil.
SOLO AERODYNAMICS
66. 66
Movement of Shocks with Increasing Mach Number
Critical Mach Number
This relation gives a unique relation between the upstream values of p∞, M∞ and the
respective values pA, MA at a point A on the Airfoil.
Assume that point A is the point of minimum pressure, therefore maximum velocity,
on the Airfoil and that this maximum velocity corresponds to MA = 1. Then by
definition M∞ = Mcr .
( )
−
−
+
−
+
=
−=
−
∞
∞∞∞
1
2
1
1
2
1
1
2
1
2
1/
2
2
γγ
γ
γ
γγ
A
A
pA
M
M
Mp
p
M
C
( )
−
−
+
−
+
=
−
1
2
1
1
2
1
1
2
1/
2
γγ
γ
γ
γ
cr
cr
p
M
M
C cr
2
0
1 ∞−
=
M
C
C
p
p
( )
−
−
+
−
+
=
−
1
2
1
1
2
1
1
2
1/
2
γγ
γ
γ
γ
cr
cr
p
M
M
C cr
2
0
1 ∞−
=
M
C
C
p
p
To find the Mcr we need on other equation describing
Cp at subsonic speeds. We can use the
Prandtl-Glauert Correction
or the Karman-Tsien Rule or
Laiton’s Rule
SOLO AERODYNAMICS
67. 67
Movement of Shocks with Increasing Mach Number
Critical Mach Number
AirfoilThickAirfoilMediumAirfoilThin
AirfoilThickAirfoilMediumAirfoilThin
crcrcr
ppp
MMM
CCC
>>
<< 000
The point of minimum pressure, therefore maximum velocity, does not correspond
to the point of maximum thickness of the Airfoil. This is because the point of
minimum pressure is defined by the specific shape of the Airfoil and not by a local
property.
The Critical Mach Number is a function of
the thickness of the Airfoil.
For the thin Airfoil the Cp0 is smaller in
magnitude and because the disturbance in the
Flow is smaller. Because of this the Critical
Mach Number of the thin Airfoil is greater
SOLO AERODYNAMICS
68. 68
Movement of Shocks with Increasing Mach Number
Drag Divergence Mach Number
The Drag at small Mach number, due to
Profile Drag with Induced Drag =0 (αi = 0)
is constant (points a, b, and c) until
M∞ = Mcr (point c). As the velocity
increase above Mcr (point d), a finite
region of supersonic flow (Weak Shock
boundary)appears on the Airfoil.
The Mach Number in this bubble of
supersonic flow is slightly above Mach 1,
typically 1.02 to 1.05. If M∞ increases more,
We encounter a point, e, at which is a sudden increase in Drag. The Value of M∞ at
which the sudden increase in Drag starts is defined as the Drag-divergence Mach
Number, Mdrag-divergence < 1. At this point Shock Waves appear on the Airfoil. The
Shock Waves are dissipative phenomena extracting energy (Drag) from the kinetic
energy of the Airfoil. In addition the sharp increase of the pressure across the
Shock Wave create a strong adverse pressure gradient, causing the Flow to
separate
From the Airfoil Surface creating Drag increase. Beyond the Drag-divergence
Mach Number, the Drag Coefficient becomes very large, increasing by a factor of
10 or more. As M∞ approaches unity (point f) the Flow on both the top and the
SOLO AERODYNAMICS
69. 69
Summary of Airfoil Drag
The Drag of an Airfoil can be described as the sum of three contributions:
iwpf DDDDD +++=
where
D – Total Drag of the Airfoil
Df – Skin Friction Drag
Dp – Pressure Drag due to Flow Separation
Dw – Wave Drag (present only at Transonic and Supersonic Speeds; zero for
Subsonic Speeds below the Drag-divergence Mach Number)
Di – Induced Drag
In terms of the Drag Coefficients, we can write:
iDwDpDfDD CCCCC ,,,, +++=
The Sum:
pDfD CC ,, + Profile Drag Coefficient
SOLO AERODYNAMICS
Aerodynamic Drag
71. 71
Relative Drag Force as a Function of Reynolds Number (Viscosity)
AERODYNAMICS
Drag CD0 due to
Flow Separation
SOLO
Aerodynamic Drag
72. 72
Relative Drag Force as a Function of Reynolds Number (Viscosity)
AERODYNAMICS
Drag due to Viscosity:
1.Skin Friction
2.Flow Separation
(Drop in pressure
behind body)
∫∫
∫∫
⋅+⋅
−
−=
⋅+⋅−=
∧∧
∞
∧∧
W
W
S
S
fpD
ds
w
t
V
f
w
n
V
pp
S
ds
w
tC
w
nC
S
C
xx
xx
11
11
ˆ
2/
ˆ
2/
1
ˆˆ
1
22
ρρ
SOLO
Aerodynamic Drag
73. 73
Effect of Mach Number on the Drag Coefficient for a given Angle of Attack (AOA)
and on the Lift Coefficient
AERODYNAMICS
Summary of Mach Effect on Drag and Lift
Return to Table of Content
74. 74
Wing Parameters
Airfoil: The cross-sectional shape obtained by the
intersection of the wing with the perpendicular plane
1. Wing Area, S, is the plan surface of the wing.
2. Wing Span, b, is measured tip to tip.
3. Wing average chord, c, is the geometric average. The product of the span and
the average chord is the wing area (b x c = S).
4. Aspect Ratio, AR, is defined as:
( )∫−
=
2/
2/
b
b
dyycS
( )
b
S
dyyc
b
c
b
b
== ∫−
2/
2/
1
S
b
AR
2
=
AERODYNAMICSSOLO
75. 75
Wing Parameters (Continue)
5. The root chord, , is the chord at the wing centerline, and the tip chord,
is the chord at the tip.
6. Taper ratio,
7. Sweep Angle,
is the angle between the line of 25 percent chord and the perpendicular
to root chord.
8. Mean aerodynamic chord,
rc
Λ
r
t
c
c
=λ
tc
λ
( )[ ]∫−
=
2/
2/
21~
b
b
dyyc
S
c
c~
AERODYNAMICSSOLO
76. 76
Wing Parameters (Continue)
AERODYNAMICS
Illustration of Wing Geometry
Planform, xy plane
Dihedral (V form),
yz plane
Profile, twist
xz plane
Geometric Designation of Wings
of various planform
Swept-back
Wing
Delta
Wing
Elliptic
Wing
SOLO
Return to Table of Content
77. 77
Wing Design Parameters
•Planform
- Aspect Ratio
- Sweep
- Taper
- Shape at Tip
- Shape at Root
•Chord Section
- Airfoils
- Twist
•Movable Surfaces
- Leading and Trailing-Edge Devices
- Ailerons
- Spoilers
•Interfaces
- Fuselage
- Powerplants
- Dihedral Angle
AERODYNAMICSSOLO
Return to Table of Content
78. SOLO
78
Aircraft Flight Control
Specific Stabilizer/Tail Configurations
Tailplane
Fuselage mounted Cruciform T-tail Flying tailplane
The tailplane comprises the tail-mounted fixed horizontal stabilizer and movable elevator.
Besides its planform, it is characterized by:
• Number of tail planes - from 0 (tailless or canard) to 3 (Roe triplane)
• Location of tailplane - mounted high, mid or low on the fuselage, fin or tail
booms.
• Fixed stabilizer and movable elevator surfaces, or a single combined stabilator or
(all) flying tail.[1]
(General Dynamics F-111)
Some locations have been given special names:
• Cruciform: mid-mounted on the fin (Hawker Sea Hawk, Sud Aviation Caravelle)
• T-tail: high-mounted on the fin (Gloster Javelin, Boeing 727)
Sud Aviation Caravelle
Gloster Javelin
79. SOLO
79
Aircraft Flight Control
Specific Stabilizer/Tail Configurations
Tailplane
Some locations have been given special names:
• V-tail: (sometimes called a Butterfly tail)
• Twin tail: specific type of vertical stabilizer arrangement found on the empennage of
some aircraft.
• Twin-boom tail: has two longitudinal booms fixed to the main wing on either side of
the center line.
The V-tail of a Belgian Air
Force Fouga Magister
de Havilland Vampire
T11, Twin-Boom Tail
A twin-tailed B-25 Mitchell
Return to Table of Content
81. 81
Run This
http://lyle.smu.edu/propulsion/Pages/propeller.htm
In small aircraft, the propeller is normally powered by a
piston engine as shown above. In larger vessels like
nuclear submarines, the propeller may be powered by a
nuclear power plant. The basic operation of a propeller
propulsion system is described in the interactive animation
below. Use the arrows to step through descriptions of the
different components.
SOLO Propeller Propulsion
82. 82
SOLO
The Rotating Parts of Jet Engine
Compressor
Shaft
Turbojet animation
Turbine
Air Breathing Jet Engines
Run This
83. 83
http://lyle.smu.edu/propulsion/Pages/variations.htm
Run This
A turbofan still has all the main components of a turbojet, but a fan and surrounding duct are added to the
front as shown in the animation below. A fan is basically a propeller with a lot of blades specially designed
to spin very quickly. Its function is essentially identical to a propeller, namely, the blades accelerate the
oncoming air flow to create thrust. In a turbofan, however, the fan is driven by turbines in the attached
turbojet engine, rather than by an internal combustion engine. Use the arrows in the interactive animation
below to step through descriptions of the different components and obtain more detailed information about
their operation.
Turbofan
84. 84
SOLO
Animation of a 2-spool, high-bypass turbofan.
A. Low pressure spool
B. High pressure spool
C. Stationary components
1. Nacelle
2. Fan
3. Low pressure compressor
4. High pressure compressor
5. Combustion chamber
6. High pressure turbine
7. Low pressure turbine
8. Core nozzle
9. Fan nozzle
Turbofan
Air Breathing Jet Engines
Run This
85. 85
SOLO
Turboprop
A turboprop engine is a type of turbine engine which
drives an aircraft propeller using a reduction gear.
The gas turbine is designed specifically for this
application, with almost all of its output being used to
drive the propeller. The engine's exhaust gases contain
little energy compared to a jet engine and play only a
minor role in the propulsion of the aircraft.
The propeller is coupled to the turbine through a
reduction gear that converts the high RPM, low torque
output to low RPM, high torque. The propeller itself is
normally a constant speed (variable pitch) type similar to
that used with larger reciprocating aircraft engines.
Turboprop engines are generally used on small subsonic
aircraft, but some aircraft outfitted with turboprops have
cruising speeds in excess of 500 kt (926 km/h, 575 mph).
Large military and civil aircraft, such as the Lockheed L-
188 Electra and the Tupolev Tu-95, have also used
turboprop power. The Airbus A400M is powered by four
Europrop TP400 engines, which are the third most
powerful turboprop engines ever produced, after the
Kuznetsov NK-12 and Progress D-27.
Air Breathing Jet Engines
Run This
86. 86http://lyle.smu.edu/propulsion/Pages/variations.htm
Turboprop Engines: A turboprop engine is basically a propeller driven by a turbojet.
Alternatively, it can be viewed as a very large bypass ratio turbofan. It is not exactly a
turbofan because there is no shroud or "duct" surrounding the propeller and the propeller
does not spin as fast as a fan. The basic components of a turboprop are illustrated in the
interactive animation below. Use the arrows to step through descriptions of the different
components.
A turboprop engine enjoys the high efficiency of a propeller, owing to the large bypass ratio it
provides. In fact, nearly all of the thrust generated by a turboprop is from the propeller. A
turboprop also enjoys the high power-to-weight ratio of turbojet engines, resulting in a
powerful compact propulsion system.
Run This
Return to Table of Content
SOLO Air Breathing Jet Engines
87. 87
SOLO Aircraft Propulsion System
Aircraft propellers or airscrews[1]
convert rotary motion from
piston engines, turboprops or electric motors to provide
propulsive force. They may be fixed or variable pitch.
Aircraft Propellers
Diesel Engine
developed in the GAP
program. Credit:
NASA
The simplest theory describing the operation of the propeller,
assumes that the rotating propeller can be approximated by a
thin Actuator Disk producing a uniform change in the velocity
of the air stream passing across it.
Actuator Disk (One-Dimensional Momentum) Theory
88. 88
SOLO Propeller Aerodynamics
Actuator Disk
2
11
2
22
2
1
2
1
VpVp ρρ +=+
2
44
2
33
2
1
2
1
VpVp ρρ +=+
Bernoulli’s equations on each side of the Disk:
Far from the Disk we have the same ambient
pressure, hence: 41 pp =
Therefore ( )2
1
2
423
2
1
VVpp −=− ρ
Conservation of Mass through the Propeller Disk
pp AVAVm 320 ρρ == 32 VV =
Conservation of Energy on both sides of the
Propeller Disk
Actuator Disk (One-Dimensional Momentum) Theory
89. 89
SOLO Propeller Aerodynamics
Actuator Disk
( )2
1
2
423
2
1
VVpp −=− ρ
The Thrust provided by the Propeller Disk is
given by:
( ) ( )143140 VVAVVVmT p −=−= ρ
where
- Fluid mass flow [kg/sec] through DiskpAVm 30 ρ=
ρ – Flow density [kg/m3
]
Ap – Disk area [m2
]
The Thrust also equals the Force on the Disk Surface due to Pressure jump:
( ) ( ) pp AVVAppT 2
1
2
423
2
1
−=−= ρ
From the two expressions of Thrust we obtain
( ) ( )2
1
2
4143
2
1
VVVVV −=− ( )413
2
1
VVV +=
Conservation of Momentum
Actuator Disk (One-Dimensional Momentum) Theory
90. SOLO Propeller Aerodynamics
Model of the Flow through Propeller
according to the Actuator Disk Concept
( )
( ) ppp
pp
VA
mVVVAT
v2v
v20143
⋅+=
=−=
∞ρ
ρ
We found
Let compute vs as function of other parameters
0
2
vv
2
=−+ ∞
p
pp
A
T
V
ρ
0
222
v
2
>+
+−= ∞∞
p
p
A
TVV
ρ
This solution corresponds to a
Propeller, where Energy is added
to the Flow.
Actuator Disk (One-Dimensional Momentum) Theory
Ideal Power Consumed by the Rotor
( )
( )
( )
+
+=
⋅=+=
+=
−+=
−=
∞∞
∞
∞
∞∞
p
p
pp
p
A
TVV
T
DiskatVelocityFlowThrustVT
Vm
VmVm
InFlowEnergyOutFlowEnergyP
ρ222
___v
vv2
2
1
v2
2
1
2
0
2
0
2
0
91. SOLO Propeller Aerodynamics
The Efficiency of an Ideal Propeller
This is called the idea1 efficiency of a propeller, which represents the upper limit
of the efficiency that cannot be exceeded whatever the shape of the propeller.
( ) ( )aaVDVAT
Va
ppp
p
+=⋅+= ∞
=
∞
∞
1
2
vv2 22
/v:
ρ
π
ρ
( ) aVV
V
VT
VT
PowerOutput
PowerInput Va
ppp
P
p
+
=
+
=
+
=
+⋅
⋅
==
∞=
∞∞
∞
∞
∞
1
1
/v1
1
vv
/v:
η
( ) p
P
P
C
JDV
P
aa 323
2
3
122
1
1
πρπη
η
==+=
−
∞
( ) ( ) aaVDVTP p
232
1
2
v +=+= ∞∞ ρ
π
( ) T
P
P
C
JDV
T
aa 2222
122
1
1
πρπη
η
==+=
−
∞
where
Actuator Disk (One-Dimensional Momentum) Theory
( )
.:
.:
:
42
53
2/
2
CoeffThrust
Dn
T
C
CoeffPower
Dn
P
C
RatioAdvance
R
V
Dn
V
J
T
p
n
RD
ρ
ρ
ππ
=
=
Ω
== ∞
Ω=
=
∞
92. SOLO Propeller Aerodynamics
The Efficiency of an Ideal Propeller ( )
.:
.:
:
42
53
2/
2
CoeffThrust
Dn
T
C
CoeffPower
Dn
P
C
RatioAdvance
R
V
Dn
V
J
T
p
n
RD
ρ
ρ
ππ
=
=
Ω
== ∞
Ω=
=
∞
E.Torenbeek, H.Wittenberg, “Flight Physics – Essentials of Aeronauical Disciplines and Technology, with
Historical Notes”, Springer, 2009
Typical Propeller Diagram
Actuator Disk (One-Dimensional Momentum) Theory
T
P
P
C
J 22
121
πη
η
=
−
p
P
P
C
J 33
121
πη
η
=
−
JV
Dn
P
VT
C
C P
p
T η
==
∞
∞
93. SOLO Propeller Aerodynamics
The Efficiency of an Ideal Propeller
E.Torenbeek, H.Wittenberg, “Flight Physics – Essentials of Aeronauical Disciplines and Technology, with
Historical Notes”, Springer, 2009
Propeller Efficiency and Advance Ratio for various flight speeds.
The Blade Pitch β is given. The change in Efficiency is due to the
change in Angle-of-Attack (due to change in Velocity V∞ or Ω),
Actuator Disk (Momentum) Theory
J
C
C
p
T
P =η
( )
.:
.:
:
42
53
2/
2
CoeffThrust
Dn
T
C
CoeffPower
Dn
P
C
RatioAdvance
R
V
Dn
V
J
T
p
n
RD
ρ
ρ
ππ
=
=
Ω
== ∞
Ω=
=
∞
94. 94
AERODYNAMICS
Asselin, M., “Introduction to Aircraft Performance”, AIAA Education Series, 1997
Actuator Disk (Momentum) Theory
SOLO
( )
RatioAdvance
R
V
Dn
V
J
n
RD Ω
== ∞
Ω=
=
∞ ππ2/
2
:
We can see that by varying
the Propeller Pitch β we
can operate at maximum
efficiency ηmax.
95. 95
SOLO Propeller Aerodynamics
E. Torenbeek, H. Wittenberg, “Flight Physics, Essentials of Aeronautical Disciplines and
Technology, with Historical Notes”, Springer, 2009, § 5.9, “Propeller Performance”, pg. 236
Propeller Blade Geometry
Variation of Angles and Velocities along a Propeller Blade
Propeller Blade have a variation of
•Twist β
•Chord c
•Thickness t
r
V
Ω
=φtan
From the Propeller Blade Geometry
– advance angleϕ [rad]
V – air velocity [m/sec], normal to rotation plane
V = V∞ + v
Ω – rotation rate [rad/sec]
r – rotation radii [m] of blade section element
φβα −=
α – angle of attack [rad] of the section element (between section chord and resultant velocity)
β – angle [rad] between section chord and rotation plane
Blade Element Theory.
96. 96
SOLO Propeller Aerodynamics
( ) ( )2222
v++Ω=+= ∞VrUUV pTres
Given a Propeller Blade Element at a distance r from
the Hub, the Resultant Velocity is given by
We have
( ) ( ) ( )
( ) ( ) ( )αραρ
αραρ
DDres
LLres
CcrVCcVDd
CcrVCcVLd
22222
22222
2
1
2
1
2
1
2
1
Ω+==
Ω+==
∞
∞
Section Lift, normal to Vres
Section Drag, opposite to Vres
Simplified view of the forces on a Propeller
Blade Element
c – chord of Propeller Blade Element
CL – Lift Coefficient of Propeller Blade Element
CD – Drag Coefficient of Propeller Blade Element
The resultant forces Normal (d T) and in the Disk Plane (d Fx) are
−
=
Dd
Ld
Fd
Td
x φφ
φφ
cossin
sincos
Blade Element Theory.
The Aerodynamic Moment and Power of the Propeller Blade Element are
QdFdrFdUPd
FdrQd
xxT
x
Ω=⋅Ω==
⋅=
97. 97
SOLO Propeller Aerodynamics
The net force acting on the blades are the summation
of the forces acting upon the individual elements.
We must multiply by the number of blades B of the
Rotor.
We have
Blade Element Theory.
( ) ( ) ( ) ( ) ( )( )
( ) ( ) ( ) ( ) ( )( )
( ) ( ) ( ) ( ) ( )( )∫∫
∫∫
∫∫
=
=
∞
=
=
=
=
∞
=
=
=
=
∞
=
=
+Ω+Ω=⋅Ω=
+Ω+=⋅=
−Ω+==
Rr
r
DL
Rr
r
x
Rr
r
DL
Rr
r
x
Rr
r
DL
Rr
r
rdrCrCrrVBcFdrBP
rdrCrCrrVBcFdrBQ
rdrCrCrVBcTdBT
0
222
0
0
222
0
0
222
0
cossin
2
1
cossin
2
1
sincos
2
1
φαφαρ
φαφαρ
φαφαρ
( )
r
V
r
Ω
+
= ∞ v
tanφ ( ) ( ) ( )rrr φβα −=
The Thrust, Aerodynamic Moment and Power of the Propeller (B blades) are
The β (r) must be twisted to have the function α (r) optimal at each section r for given V∞
and Ω. If V∞ changes by rotating the Propeller around it’s axis (Pitch) we change β (r) to
optimize again α (r).
98. 98
SOLO Propeller Aerodynamics
Blade Element Theory.
42
22
242
53
32
253
2
2
4
:
4
:
:
D
T
Dn
T
C
R
P
Dn
P
C
RatioAdvance
R
V
Dn
V
J
n
RD
T
n
RD
p
n
RD
Ω
==
Ω
==
Ω
==
Ω
=
=
Ω
=
=
∞
Ω
=
=
∞
ρ
π
ρ
ρ
π
ρ
π
π
π
π
( ) ( ) ( ) ( )( )∫
=
=
∞
−
+
Ω
=
Ω
=
Rr
r
DLT
R
r
drCrC
R
r
R
V
R
cB
R
T
C
0
2
2
2
22
22
42
2
sincos
84
φαφαπ
π
π
π
ρ
π
σ
( ) ( ) ( ) ( )( )∫
=
=
∞
+
+
Ω
=
Ω
=
Rr
r
DLP
R
r
drCrC
R
r
R
rV
R
Bc
R
P
C
0
2
2
2
2
22
53
3
cossin
84
φαφαππ
π
π
π
ρ
π
σ
We have
or
Let use the definitions:
( )
Solidity
R
cB
R
RcB
DiskSurface
ElementsBladeSurface
==
==
π
π
σ 2
:
( ) ( ) ( ) ( ) ( )( )∫
=
=
=
−+=
1
0
222
/
sincos
8
x
x
DL
Rrx
T xdxCxCxJC φαφαπσ
π
Thrust Coefficient
( ) ( ) ( ) ( ) ( )( )∫
=
=
=
++=
1
0
222
/
cossin
8
x
x
DL
Rrx
P xdxCxCxxJC φαφαππσ
π Power Coefficient
99. 99
SOLO Propeller Aerodynamics
Blade Element Theory.
42
22
242
53
32
253
2
2
4
:
4
:
:
D
T
Dn
T
C
R
P
Dn
P
C
RatioAdvance
R
V
Dn
V
J
n
RD
T
n
RD
p
n
RD
Ω
==
Ω
==
Ω
==
Ω
=
=
Ω
=
=
∞
Ω
=
=
∞
ρ
π
ρ
ρ
π
ρ
π
π
π
π
Characteristic Curves of a Propeller
Propeller Efficiency.
J
C
C
Dn
V
C
C
CDn
VCDn
P
VT
P
T
P
T
P
T
==== ∞∞∞
53
42
ρ
ρ
η
100. 100
SOLO Propeller Aerodynamics
Fuel Consumption
For
VTPP ppA ⋅⋅=⋅= ηηThe Available Power is
ηp – propulsive efficiency
For a given throttle setting, a regular piston engine,
that aspire atmospheric air, produces power that is
almost constant with velocity but decreases as the
altitude increases (air density decreases).
VTP ⋅=
Propeller Propulsion
The fuel mass flow is proportional to engine power P
pApp PcPcWf η/==−=
cp – power specific fuel consumption
VPT /=
The engine power is
=
=
restratosphe
etropospher
x
P
P
x
1
75.0
00 ρ
ρ
101. 101
H.H. Hurt, Jr., “Aerodynamics for Naval Aviators “,NAVAIR 00=80T-80 1-1-1965, pg. 35
Asselin, M., “Introduction to Aircraft
Aerodynamics”, AIAA Education Series, 1997
Return to Table of Content
102. 102
Most jet engines are Turbofans and some are
Turbojets which use gas turbines to give high pressure
ratios and are able to get high efficiency, but a few use
simple ram effect or pulse combustion to give
compression.
Most commercial aircraft possess turbofans, these
have an enlarged air compressor which permit them to
generate most of their thrust from air which bypasses
the combustion chamber.
AIR BREATHING JET ENGINESSOLO
Operation of Aircraft Turbojet EngineAircraft Turbo Engines
The turboprop engine : Turboprop engine derives its
propulsion by the conversion of the majority of gas
stream energy into mechanical power to drive the
compressor , accessories , and the propeller load. The
shaft on which the turbine is mounted drives the
propeller through the propeller reduction gear system .
Approximately 90% of thrust comes from propeller and
about only 10% comes from exhaust gas.
The turbofan engine : Turbofan engine has a duct
enclosed fan mounted at the front of the engine and driven
either mechanically at the same speed as the compressor ,
or by an independent turbine located to the rear of the
compressor drive turbine . The fan air can exit separately
from the primary engine air , or it can be ducted back to
mix with the primary's air at the rear . Approximately more
than 75% of thrust comes from fan and less than 25%
comes from exhaust gas.
103. 103
Propulsion Force = Thrust
SOLO
The net Thrust ( T ) of a Turbojet is given by
where:
ṁ air = the mass rate of air flow through the engine
ṁ fuel = the mass rate of fuel flow entering the engine
Ue = the velocity of the jet (the exhaust plume)
U0 = the velocity of the air intake = the true airspeed of the aircraft
(ṁ air + ṁ fuel )Ue = the nozzle gross thrust (FG)
ṁ air U0 = the ram drag of the intake air
Aircraft Propulsion System
( )[ ] ( ) airfueleeeair mmfAppUUfmTHRUST /:1 00 =−+−+==T
Jet Engines Thrust Force
Introduction to Air Breathing Jet Engines
00 ,Up
0A
eA
ee Up ,
104. 104
Turbojet
SOLO
Thrust Computation for Air Breathing Engines
( ) ( )
DRAGFRICTION
A
WA
DRAGPRESURE
A
WA
THRUST
eeeeex
WW
AdAdppAppAUAUF ∫∫∫∫ −−−−+−= θτθρρ cossin000
2
00
2
00000 & mAUmmAU feee
=+= ρρUsing C.M.
( ) ( ) 00000
2
00
2
UmUmmAppAUAUTHRUST efeeeee
−+=−+−= ρρ
or
we obtain
( )[ ] ( ) 0000 /:1 mmfAppUUfmTHRUST feee
=−+−+==T
and ( )
DRAGFRICTION
A
WA
DRAGPRESURE
A
WA
WW
AdAdppDRAGD ∫∫∫∫ +−== θτθ cossin0
00 ,Up
0A
eA
ee Up ,
Air Breathing Jet Engines
Pressure force
Friction force
Wetted Surface
Aerodynamic Forces on Wetted Surfaces
105. 105
Turbojet
SOLO
Thrust Computation for Air Breathing Engines (continue – 1)
since
and
00 ,Up
0A
eA
ee Up ,
( ) 0
00000
00
00
/:111 mmf
A
A
p
p
U
U
f
Ap
Um
Ap
f
eee
=
−+
−+=
T
2
0
2
0
00
002
0
0
2
00
0
2
00
00
2
000
00
00
MM
TR
TR
M
p
a
p
U
Ap
UA
Ap
Um
γ
ρ
γρρρρ
=====
( ) 0
000
2
0
00
/:111 mmf
A
A
p
p
U
U
fM
Ap
f
eee
=
−+
−+= γ
T
000
2
00
0
00
000000 MApaM
TR
Ap
aUAam γρ ===
( ) 0
0000
0
00000
/:1
1
11
1
mmf
A
A
p
p
MU
U
fM
ApMam
f
eee
=
−
+
−+=
=
γγ
TT
Air Breathing Jet Engines
106. 106
Turbojet
SOLO
Thrust Computation for Air Breathing Engines (continue – 2)
00 ,Up
0A
eA
ee Up ,
000
0
00
00 11
:
ApMg
a
famg
a
m
m
gmWeightFuelBurned
ForceThrust
I
ff
sp
TTT
====
γ
Specific Impulse
0000
11
ApMfa
gIsp T
=
γ
Specific Fuel Consumption (SFC)
spIg
f
ThrustofPound
HourperBurnedFuelofPound
S
1
: ====
0
f
mT/T
m
Air Breathing Jet Engines
107. 107
Air Breathing Jet Engines
PRESSURE
Compressor
Pressure
Rise
Turbine
Pressure
Drop
(Turbojet)
Heat Added in
Combustion Chambers
by burning mfuel mass
TOTAL TEMPERATURE
mfuel_1
mfuel_2
mfuel_3
mfuel_1 >mfuel_2>mfuel_3
Pressure corresponding to
mfuel_1 and Thrust1
Pressure corresponding to
mfuel_2 and Thrust2
Pressure corresponding to
mfuel_3 and Thrust3A
B1
B2
B3
C1
D1
C2
D2
C3
D3
Thrust1 >Thrust2>Thrust3
E
108. 108
Air Breathing Jet Engines
PRESSURE
Compressor
Pressure
Rise
Turbine
Pressure
Drop
(Turbojet)
Heat Added in
Combustion Chambers
by burning mfuel mass
TOTAL TEMPERATURE
Pressure corresponding to
mfuel and ThrustA
B
C
D1
F
E
Additional Turbine
Pressure Drop
in Turboprop
109. 109
( )[ ] ( ) 0000 /:1 mmfAppUUfm feee
=−+−+=T
00 ,Up
0A
eA
ee Up ,
Aircraft Propulsion SystemSOLO
0000 UAm ρ=
The change in altitude (air density) will affect the thrust as follows
As U0 increases Ue doesn’t change (at the first order), since the value of Ue depends more of the
internal compression and combustion processes inside the engine than on the U0. Therefore Ue – U0
will decrease. Since increase in U0 increases ṁ0 , the Thrust T will remain, at first order, constant.
0UwithconstantelyapproximatisT
..LSS.L. ρ
ρ
=
T
T
Sensitivity of Thrust and Specific Fuel Consumption with
Velocity and Altitude for a Jet Engine
J.D. Anderson, Jr., “Aircraft Performance and Design”, McGraw Hill, 1999
The Specific Fuel Consumption increases with Mach at subsonic velocity (see Figure next slide)
11 00 <+= MMkTSFC
The Specific Fuel Consumption is constant with altitude at subsonic velocity (see Figure next slide)
altitudewithconstantisTSFC
110. 110
Typical results for the variation of Thrust and Thrust Specific Fuel Consumption with
Subsonic Mach number for a Turbojet
J.D. Anderson, Jr., “Aircraft Performance and Design”, McGraw Hill, 1999
Aircraft Propulsion SystemSOLO
Sensitivity of Thrust and Specific Fuel Consumption with
Velocity and Altitude for a Jet Engine
111. 111
Typical results for the variation of Thrust
and Thrust Specific Fuel Consumption
with Supersonic Mach number for a
Turbojet
J.D. Anderson, Jr., “Aircraft Performance and Design”, McGraw Hill, 1999
Aircraft Propulsion SystemSOLO
Sensitivity of Thrust and Specific Fuel Consumption with
Velocity and Altitude for a Jet Engine
Supersonic Conditions
1
2
2
1
1
−
−
+=
γ
γ
γ
M
p
p
static
total
Ptotal is the pressure entering the
Compressor from the Diffuser,
that further increases the
pressure and therefore the exit
Velocity Ue and the Thrust.
From the Figure we obtain that
for the specific aircraft the
Supersonic Thrust is given by
( )118.11 0
1
−+=
=
M
MT
T
..LSS.L. ρ
ρ
=
T
T
The Specific Fuel Consumption is constant with Mach at supersonic velocity (see Figure)
The Specific Fuel Consumption is constant with altitude at supersonic velocity (see Figure)
altitudewithconstantisTSFC
10 >MMachwithconstantisTSFC
112. 112
H.H. Hurt, Jr., “Aerodynamics for Naval Aviators “,NAVAIR 00=80T-80 1-1-1965, pg. 35
Turbojet Performance
Aircraft Propulsion SystemSOLO
Return to Table of Content
113. 113
SOLO
Thrust Augmentation – Reheat in an Afterburner
Aircraft Propulsion System
To achieve Take-Off from a Short Runway a Fighter Aircraft needs additional Thrust. This is also necessary in
Dogfight Combat to increase Aircraft Maneuverability.
A very effective and widely used method to increase Thrust is by Reheat or Afterburning which enables Thrust
to be increased by 50 percent. The technology of Reheat is possible because the hot gas after passing the Turbine,
still contains enough oxygen to allow a Second Combustion given additional Fuel is Injected. (Only part of the
air is discharged by the Compressor is used for Combustion, the greater part is used for Cooling).
The Afterburner is a Tube-like structure attached to the Gas Generator immediately
behind the Turbine. The forward part is designed as a Diffuser (increasing cross-
section) which decrease flow velocity from Mach 0.5 to 0.2. It consists of the following
four components:
- Flame Tube
- Fuel Injection System
- Flame Holder Assembly (prevent Flame for being carried away)
- Variable Geometry Exhaust Nozzle
Afterburner
114. 114
SOLO
Ideal Turbojet Engine with Afterburner
Pressure-Volume Diagram Temperature-Entropy
Diagram
Ideal Turbojet with Afterburner
eA
ee Up ,
00 ,Up
0A
Air Breathing Jet Engines
Typical afterburning jet pipe equipment.
Afterburner
Return to Table of Content
118. 118
Velocityvariation
PA isconstantwithM’
Altitude variation
PA/PA,0 =(ρ/ρ0)m
Velocityvariation
CA isconstantwithV’
Altitude variation
CA isconstantwithAltitude
Specificfuel
Consumption
Power
PA=(TP+Tj)V’
PA=hpr PS+Tj V’
PA=hpr Pes
Turboprop
Engine
J.D. Anderson, Jr., “Aircraft Performance and Design”, McGraw Hill, 1999, pg.186
Aircraft Propulsion
Summary
Block Diagram
Aircraft Propulsion SystemSOLO
Aircraft Propulsion Summary
119. 119
Altitude variation
1. P/P0 = ρ/ρ0
2. (slightly more accurate) P/P0 =1.132 ρ/ρ0-0.132
Velocity variation
Shaft Power P constant with V’
Velocity variation
SFC is constant with V’
Altitude variation
SFC is constant with Altitude
Altitude variation
T/T0 = ρ/ρ0
Velocity variation
1.Subsonic: T is constant with V’
2. Supersonic: T/Tm=1=1+1.18 (M’-1)
Velocity variation
1. Subsonic: TSFC = 1.0+k M’
2. Supersonic: TSFC is constant’
Altitude variation
SFC is constant with Altitude
Altitude variation
T/T0 =( ρ/ρ0 )m
Velocity variation
1High bypass ratio: T/TV=0=A M’
-n
2. Low bypass ratio: T first increases with M’
then decreases at high supersonic M’
Velocity variation
1. High Bypass ct = B (1.0+k M’ )
2.Low Bypass: ct graduately increases with velocity
Altitude variation
c t is constant with Altitude
Velocity variation
PA is constant with M’
Altitude variation
PA/PA,0 = (ρ/ρ0)m
Velocity variation
CA is constant with V’
Altitude variation
CA is constant with Altitude
Specific fuel
Consumption
Specific fuel
Consumption
Specific fuel
Consumption
Specific fuel
Consumption
Power
PA =T V’
Power
PA =T V’
Power
PA = hpr P
hpr = f (J)
J = V’/(N D)
Power
PA =(TP+Tj) V’
PA = hpr PS+Tj V’
PA = hpr Pes
Reciprocating Engine/
Propeller Combination
Turbojet
Engine
Turbofan
Engine
Turboprop
Engine
Propulsion Systems
J.D. Anderson, Jr., “Aircraft Performance and Design”, McGraw Hill, 1999, pg.186
Aircraft Propulsion
Summary
Block Diagram
Aircraft Propulsion SystemSOLO
124. 124Stengel, MAE331, Lecture 6
Thrust of a Propeller-
Driven Aircraft
• With constant r.p.m., variable-pitch propeller
where
ηp - propeller efficiency
ηI - ideal propulsive efficiency
ηnet-max ≈ 0.85 – 0.9
Efficiency decrease with airspeed
Engine power decreases with altitude
- Proportional with air density w/o supercharger
V
P
V
P
T
engine
net
engine
Ip ηηη ==
Variation of Thrust and Power of a Propeller-Driven Aircraft with True Airspeed
Aircraft Propulsion Summary
SOLO Aircraft Propulsion System
125. 125
Thrust as a function of airspeed for different Propulsion Systems
Aircraft Propulsion Summary
SOLO Aircraft Propulsion System
126. 126
Stengel, MAE331, Lecture 6
Thrust of a
Turbojet
Engine
( )
−
+−
−
−
= 11
11
2/1
00
0
c
t
c
t
t
VmT
τθ
θ
τ
θ
θ
θ
θ
fuelair mmm +=
( )
heatsspecificofratio
p
p
ambient
stag
=
=
−
γθ
γγ
,
/1
0
=
etemperaturambientfreestream
etemperaturinletturbine
0θ
=
etemperaturinletcompressor
etemperaturoutletcompressor
cτ
• Little change in thrust with airspeed below Mcrit
• Decrease with increasing altitude
where
Variation of Thrust and Power of a Turbojet Engine with True Airspeed
SOLO Aircraft Propulsion System
127. 127
Stengel, MAE331, Lecture 6
John D. Anderson, Jr., “Introduction to Flight”, McGraw Hill, 1978, § 6.4, pg. 217
B. N. Pamadi, “Performance, Stability, Dynamics and Control of Aircraft”, AIAA
SOLO Aircraft Propulsion System
128. 128
Power and Thrust
• Propeller
• Turbojet
• Throttle Effect
airspeedoftindependenSVCVTPPower T ≈=•== 3
2
1
ρ
airspeedoftindependenSVCTThrust T ≈== 2
2
1
ρ
10
2
1 2
max max
≤≤== TSVTCTTT T δρδδ
Specific Fuel Consumption, SFC = cP or cT
• Propeller aircraft
• Jet aircraft
[ ]
[ ]
→
→
=
−=
−=
lbf
slb
or
kN
skg
c
HP
slb
or
kW
skg
c
weightfuelw
where
thrusttoalproportionTcw
powertoalproportionPcw
T
P
f
Tf
Pf
//
//
SOLO Aircraft Propulsion System
Return to Table of Content
129. 129Dr. Carlo Kopp, Air Power Australia,
Sukhoi Su-34 Fullback, Russia's New Heavy Strike Fighter
Comparison of Fighter Aircraft Propulsion Systems
SOLO
132. 132M. Corcoran, T. Matthewson, N. W. Lee, S. H. Wong, “Thrust Vectoring”
Comparison of Fighter Aircraft Propulsion Systems
SOLO
133. 133M. Corcoran, T. Matthewson, N. W. Lee, S. H. Wong, “Thrust Vectoring”
Comparison of Fighter Aircraft Propulsion Systems
SOLO
134. 134M. Corcoran, T. Matthewson, N. W. Lee, S. H. Wong, “Thrust Vectoring”
Comparison of Fighter Aircraft Propulsion Systems
SOLO
135. 135M. Corcoran, T. Matthewson, N. W. Lee, S. H. Wong, “Thrust Vectoring”
Comparison of Fighter Aircraft Propulsion Systems
SOLO
136. 136M. Corcoran, T. Matthewson, N. W. Lee, S. H. Wong, “Thrust Vectoring”
Return to Table of Content
Comparison of Fighter Aircraft Propulsion Systems
SOLO
137. 137
SOLO Aircraft Propulsion System
VTOL - Vertical Take off and Landing capability
The advantages of vertical take off and landing VTOL are quite obvious.
Conventional aircraft have to operate from a small number of airports with
long runways. VTOL aircraft can take off and land vertically from much
smaller areas.
STOL - Short takeoff and landing
These aircraft using thrust vectoring to decrease the distance needed for
takeoff and landing but don’t have enough thrust vectoring capability to
perform a vertical take off or landing.
VSTOL - An aircraft that can perform either vertical or short takeoff and landings
STOVL - Short takeoff and vertical land.
An aircraft that has insufficient lift for vertical flight at takeoff weight but
can land vertically at landing weight.
TVC - Thrust Vector Control
Vertical Take off and Landing - VTOL
139. 139M. Corcoran, T. Matthewson, N. W. Lee, S. H. Wong, “Thrust Vectoring”
140. 140
Lockheed_Martin_F-35_Lightning_II STOVL
The Unique F-35
Fighter Plane, Movie
USP 3” part F35
Joint Strike Fighter ENG,
Movie
SOLO Aircraft Propulsion System
Thrust vectoring nozzle
of the F135-PW-600
STOVL variant
Return to Table of Content
141. 141
Aircraft Propulsion System
SOLO
Engine Control System
Engine Control System
Basic Inputs and Outputs
Engine Control System
Input Signals:
• Throttle Position (Pilot Control)
• Air Data (from Air Data Computer)
Airspeed and Altitude
• Total Temperature (at the Engine
Face)
• Engine Rotation Speed
• Engine Temperature
• Nozzle Position
• Fuel Flow
• Internal Pressure Ratio at different Stages of the Engine
Output Signals
• Fuel Flow Control
• Air Flow Control
142. 142
Aircraft Propulsion SystemSOLO
The Fighter Aircraft Propulsion Systems Consists of:
- One or Two Jet Engines
- The Fuel Tanks (Internal and External) and Pipes.
- Engines Control Systems
* Throttles
* Engine Control Displays
Engine Control Systems – Basic Inputs and Outputs
143. 143
Aircraft Propulsion SystemSOLO
A Simple Engine Control Systems :
Pilot in the Loop
A Simple Limited Authority
Engine Control Systems
TGT – Turbine Gas Temperature
NH – Speed of Rotation of Engine Shaft
Tt - Total Temperature
FCU – Fuel Control Unit
Engine Control System
144. 144
Aircraft Propulsion SystemSOLO
A Simple Engine Control Systems :
Pilot in the Loop
A Simple Limited Authority
Engine Control Systems
Engine Control Systems :
with NH and TGT exceedance warning
Full Authority Engine Control Systems
With Electrical Throttle Signaling :
Engine Control System Return to Table of Content
146. 146
center stickailerons
elevators
rudder
Aircraft Flight Control
Generally, the primary cockpit flight controls are arranged as follows:
a control yoke (also known as a control column), center stick or side-stick (the
latter two also colloquially known as a control or B joystick), governs the
aircraft's roll and pitch by moving the A ailerons (or activating wing warping
on some very early aircraft designs) when turned or deflected left and right,
and moves the C elevators when moved backwards or forwards
rudder pedals, or the earlier, pre-1919 "rudder bar", to control yaw, which move
the D rudder; left foot forward will move the rudder left for instance.
throttle controls to control engine speed or thrust for powered aircraft.
SOLO
148. 148
The effect of left rudder pressure Four common types of flaps
Leading edge high lift devices
The stabilator is a one-piece horizontal tail surface that
pivots up and down about a central hinge point.
Aircraft Flight ControlSOLO
155. 02/28/15 155
SOLO
By changing αT from 0 to αMAX, and rotating around
by σ (from 0 to σMAX) we obtain a Surface of Revolution
Σq (CA,CN) which defines the Achievable Aerodynamic
Forces for the given dynamic pressure q.
rV1
( )
( )
VzVyV
MAXT
soundr
r
windr
nnn
hVVM
VShq
vRVV
1sin1cos1
/
2
1 2
σσ
αα
ρ
+=
≤
=
=
−×Ω−=
( ) ( ) ( )
( ) ( ) VTLrTD
VTrTT
nMCqVMCq
nMqLVMqDMqA
1,1,
1,,1,,,,
αα
ααα
+−=
+−=
( ) ( )
T
rTB
rB
rrBB
rB
rB
rV
Vx
Vx
VVxx
Vx
Vx
Vn
α
α
sin
1cos1
11
1111
11
11
11
−
=
×
⋅−
=
×
×
×=
( )σα,A
V
α
MAXα
( )DL CC ,Σ
σ
MAXσ
( ) ( )αα
2
0 LDD CkCC +=
D
σcosL
σsinL
σ
MAXσ
L
L
Aerodynamic Forces (Vectorial)
Aircraft Equations of Motion
156. 02/28/15 156
SOLO
We can see that for αT = 0
( ) ( )
( )
( )
( )
MA
Ar
MD
DT
TT
MCqVMCqMqA
,0
0
,0
0 1,0,
==
−=−==
αα
α
( ) ( )Rg
m
T
V
m
MCq
V r
D
++−= 10
and since for αT = 0
the aerodynamic forces will
decrease the velocity.
We can see that for αT ≠ 0, the deceleration
due to aerodynamics will only increase.
( ) ( ) ( )[ ] ( ) ( )MqDMCqMCMCqMqD TATTNTAT ,0,sincos,0, ==>+=≠ ααααα α
The most Energy Effective Trajectory is one with αT = 0.
( )
( )
VzVyV
MAXT
soundr
r
windr
nnn
hVVM
VShq
vRVV
1sin1cos1
/
2
1 2
σσ
αα
ρ
+=
≤
=
=
−×Ω−=
( ) ( )
T
rTB
rB
rrBB
rB
rB
rV
Vx
Vx
VVxx
Vx
Vx
Vn
α
α
sin
1cos1
11
1111
11
11
11
−
=
×
⋅−
=
×
×
×=
( ) ( ) ( )
( ) ( ) VTLrTD
VTrTT
nMCqVMCq
nMqLVMqDMqA
1,1,
1,,1,,,,
αα
ααα
+−=
+−=
Aerodynamic Forces (Vectorial)
Aircraft Equations of Motion
Return to Table of Content
157. 02/28/15 157
SOLO
Specific Energy
( ) ( )RgTA
m
V
++=
1
( ) ( ) ( ) VTrTT nMqLVMqDMqA 1,,1,,,, ααα +−=
By Integrating this Equation we obtain:
( ) ( )∫∫ +⋅=
⋅−
⋅
=−
t
t
t
t
dtTAV
gm
dt
g
Rg
V
g
VV
EE
00 000
0
1
( ) ( ) ( )∫∫∫∫ ∫ +⋅=⋅
−
−
−
=⋅−
⋅
=
⋅−
⋅
=−
t
t
R
R dRR
E
R
R
t
t
V
V
dtTAV
gm
RdR
Rgg
VV
Rd
g
Rg
g
VdV
dt
g
Rg
V
g
VV
EE
0000 0
0
3
00
2
0
2
0000
0
11
2
µ
Define Specific Energy Derivative:
( ) ( )TAV
mg
Rg
V
g
VV
E
+⋅=⋅−
⋅
=
1
:
00
2
0
0 :
R
g Eµ
=
( )∫ +⋅=
−−
−=
−−
−
=−
t
t
EEE
dtTAV
gmRgg
V
Rgg
V
RRgg
VV
EE
0 0000
2
0
00
2
000
2
0
2
0
1
22
11
2
µµµ
Aircraft Equations of Motion
158. 02/28/15 158
SOLO
Specific Energy (continue – 1)
( ) ( )∫∫ +⋅=
⋅−
⋅
=−
t
t
t
t
dtTAV
gm
dt
g
Rg
V
g
VV
EE
00 000
0
1
0
2
0
2
00 20 0
g
VV
g
VdV
dt
g
VV
t
t
V
V
−
=
⋅
=
⋅
∫ ∫
( ) ( )
( )
( ) 0
3
0
3
2
0
02
0
2
2
2
0
3
2
0
00
0
0
0
0
00
3
2
0
0
00
3
2
21 hhhh
R
hhhd
R
h
Rd
R
R
RdR
R
R
Rd
g
Rg
dt
g
Rg
V
Rhh
h
hRR
Rh
R
R
dRRRdRR
R
R
R
Rg
R
g
R
R
t
t
RddtV
E
E
−≈−−−=
−≈
=⋅=⋅−=
⋅−
<<+=
<<
=⋅
−=
=
=
∫
∫∫∫∫
µ
µ
( ) ( ) ( )[ ]∫∫ −⋅=+⋅
t
t
T
t
t
dtMqDTTV
gm
V
dtTAV
gm 00
,,11
1
00
α
Specific Kinetic Energy
Specific Potential Energy
( ) ( )[ ]∫ −⋅=
+−
+=−
t
t
T dtMqDTTV
gm
V
h
g
V
h
g
V
EE
0
,,11
22 0
0
0
2
0
0
2
0 α
Specific Energy Gain due to Thrust
and Loss due to Aerodynamic Drag
( )011 >⋅ TVif
Aircraft Equations of Motion
Return to Table of Content
159. SOLO
( ) ( )
( ) ( ) ( ) ( )
( ) ( )
≥==−=
≥+×Ω=−=++=
===
min00
min00
00
/
1
mmtmmtmcTm
VVvRtVRpATTRgTA
m
V
RtRRtRVR
ffvacuum
fwindaevacuum
ff
Equations of Motion (State Equations): . ( ) ( ) fttttuxftx ≤≤= 0,,, π
Controls: ( ) fttttu ≤≤0
VectorThrustT
ForcescAerodynamiA
−
−
Three Degrees of Freedom Model in Earth Atmosphere
161. 161
SOLO
• Rotation Matrix from Earth to Wind Coordinates
[ ] [ ] [ ]321 χγσ=W
EC
where
σ – Roll Angle
γ – Elevation Angle of the Trajectory
χ – Azimuth Angle of the Trajectory
Force Equation:
amgmTFA
=++
where:
• Aerodynamic Forces (Lift L and Drag D)
( )
−
−
=
L
D
F
W
A 0
• Thrust T ( )
=
α
α
sin
0
cos
T
T
T W
• Gravitation acceleration
( ) ( )
−
−
−
==
g
cs
sc
cs
sc
cs
scgCg EW
E
W
0
0
100
0
0
0
010
0
0
0
001
χχ
χχ
γγ
γγ
σσ
σσ
( )
g
cc
cs
s
g W
−
=
γσ
γσ
γ
α
T
V
L
D
Bx
Wx
Bz
Wz
Wy
By
Flat Earth Three Degrees of Freedom Aircraft Equations
162. 162
SOLO
α
T
V
L
D
Bx
Wx
Bz
Wz
Wy
By
• Aircraft Acceleration
( )
( )
( ) ( )WW
W
W
VVa
×+=
→
ω
where:
( )
=
0
0
V
V W
and
( )
=
→
0
0
V
V
W
( )
−+
−
+
−
=
=
χ
χχ
χχ
γ
γγ
γγσ
σσ
σσω
0
0
100
0
0
0
0
0
010
0
0
0
0
0
001
cs
sc
cs
sc
cs
sc
r
q
p
W
W
W
W
or ( )
+−
+
−
=
=
γσχσγ
γσχσγ
γχσ
ω
ccs
csc
s
r
q
p
W
W
W
W
therefore
( )
( )
( ) ( )
( )
( )
+−
+−=
−
=×+=
→
γσχσγ
γσχσγω
cscV
ccsV
V
qV
rV
V
VVa
W
W
WW
W
W
Flat Earth Three Degrees of Freedom Aircraft Equations
163. 163
SOLO
α
T
V
L
D
Bx
Wx
Bz
Wz
Wy
By
• Aircraft Acceleration
Flat Earth Three Degrees of Freedom Aircraft Equations
From the Force equation we obtain:
( )
( )
( ) ( ) ( ) ( )
( ) ( )WWW
A
WW
W
W
gTF
m
VVa
++=×+=
→
1
ω
or
( )
( ) ( )
++−=+−=−
=+−=
−−=
γσαγσχσγ
γσγσχσγ
γα
ccgmLTcscVqV
csgccsVrV
sgmDTV
W
W
/sin
/)cos(
from which we obtain:
−
+
=
=
γσ
α
γσ
coscos
sin
cossin
V
g
Vm
LT
q
V
g
r
W
W
164. 164
SOLO
α
T
V
L
D
Bx
Wx
Bz
Wz
Wy
By
• Aircraft Acceleration
Flat Earth Three Degrees of Freedom Aircraft Equations
From the Force equation we obtain:
( )
( )
( ) ( ) ( ) ( )
( ) ( )WWW
A
WW
W
W
gTF
m
VVa
++=×+=
→
1
ω
or
( )
( ) ( ) σ
σ
σ
σ
γσαγσχσγ
γσγσχσγ
γα
s
c
c
s
ccgmLTcscVqV
csgccsVrV
sgmDTV
W
W
−−
−
++−=+−=−
=+−=
−−=
/sin
/)cos(
from which we obtain:
( )
( )
+=
−+=
−−=
msLTcV
cgmcLTV
sgmDTV
/sin
/sin
/)cos(
σαγχ
γσαγ
γα
Define the Load Factor
gm
LT
n
+
=
αsin
:
165. 165
SOLO
α
T
V
L
D
Bx
Wx
Bz
Wz
Wy
By
• Velocity Equation
Flat Earth Three Degrees of Freedom Aircraft Equations
( ) ( )
==
=
0
0
V
CVC
h
y
x
V E
W
WE
W
E
−
−
−
=
0
0
0
0
001
0
010
0
100
0
0 V
cs
sc
cs
sc
cs
sc
h
y
x
σσ
σσ
γγ
γγ
χχ
χχ
=
=
=
γ
χγ
χγ
sVh
scVy
ccVx
or
• Energy per unit mass E
g
V
hE
2
:
2
+=
Let differentiate this equation:
( )
W
VDT
W
DT
g
g
V
V
g
VV
hEps
−
=
−
−
+=+==
α
γ
α
γ
cos
sin
cos
sin:
Return to Table of Content
166. 166
SOLO
Flat Earth Three Degrees of Freedom Aircraft Equations
We have
Aircraft Thrust( ) 10, ≤≤= ηη VhTT MAX
( ) ( ) soundofspeedhaNumberMachMhaVM === &/
( ) ( )MSCVhL L ,
2
1 2
αρ= Aircraft Lift
( ) ( )LD CMSCVhD ,
2
1 2
ρ= Aircraft Drag
( ) ( )
ARe
k
CkMCCMC
iDC
LDLD
π
1
,
2
0
=
+=
Parabolic Drag Polar
gm
LT
n
+
=
αsin
' Total Load Number
( ) 0/
0
hh
eh −
= ρρ Air Density as Function of Height
gm
L
n = Load Factor
167. 167
SOLO
Constraints:
State Constraints
• Minimum Altitude Limit
minhh ≥
• Maximum dynamic pressure limit
( ) ( )hVVorqVhq MAXMAX ≤≤= 2
2
1
ρ
• Maximum Mach Number limit
( ) MAXM
ha
V
≤
Aerodynamic or heat limitation
Three Degrees of Freedom Model in Earth Atmosphere
168. 168
SOLO
Constraints:
• Maximum Load Factor
( )
MAXn
W
VhL
n ≤=
,
• Maximum Roll Angle
MAXMAX σσσ ≤≤−
• Maximum Lift Coefficient or Maximum Angle of Attack
( ) ( ) ( )VhorMCMC STALLMAXLL ,, _ ααα ≤≤
( )
( )
( ) ( ) ( ) LSTALL
LMAXL
nVh
W
VhC
VSh
W
VhC
VShn ==≤ ,
,
2
1,
2
1 2_2
αρρ α
Control Constraints (continue): ( ) fttttuU ≤≤≤ 00,
Three Degrees of Freedom Model in Earth Atmosphere
169. 02/28/15
169
SOLO
Control Constraints: ( ) fttttuU ≤≤≤ 00,
• Thrust Controls options are:
Thrust Direction
Thrust Magnitude
( ) throttableVhTT rMAX 10, ≤≤= ηη
Deflector Nozzle
Thrust Reversal Operation
F-35 Propulsion
If no Thrust Vector Control (No TVC)
BxT 11 =
1cos111 max ≤≤•≤− TBxT δ
If Thrust Vector Control (TVC)
Three Degrees of Freedom Model in Earth Atmosphere
170. 02/28/15 170
( ) ( )
( ) ( ) ( )( )
( )
( ) ( ) ( )( )
( )
( ) ( )( ) ( ) ( )
γ
χ
γ
χγ
χγσ
γ
α
σ
γ
βα
χ
χγγ
χγσ
α
σ
βα
γ
χγγ
γ
βα
χγ
χγ
γ
cos
sincossin
cos
sincoscostan2
tansincossin
cos
sin
cos
cos
sincos
cossinsincoscoscos
coscos2coscos
sin
sin
sincos
sinsincoscossincos
sin
coscos
sincos
cos
coscos
cos
sin
*
2
*
2
2
*
V
a
LatLat
V
R
LatLat
Lat
R
V
Vm
LT
Vm
CT
V
a
LatLatLat
V
R
Lat
V
g
R
V
Vm
LT
Vm
CT
LatLatLatR
ag
m
DT
V
R
V
R
V
td
Latd
LatR
V
LatR
V
td
Longd
V
td
Rd
yWW
zWW
xWW
E
N
−
Ω
+−Ω−
−
+
+
+
−=
−+
Ω
+
Ω+
−+
+
+
+
=
−Ω+
−−
−
=
==
==
=
(a) Spherical, Rotating Earth (Ω ≠ 0)
SOLO Three Degrees of Freedom Model in Earth Atmosphere
171. 02/28/15 171
(b) Spherical, Non-Rotating Earth (Ω = 0)
( ) ( )
( )Lat
R
V
Vm
LT
Vm
CT
V
g
R
V
Vm
LT
Vm
CT
ag
m
DT
V
R
V
R
V
td
Latd
LatR
V
LatR
V
td
Longd
V
td
Rd
xWW
E
N
tansincossin
cos
sin
cos
cos
sincos
coscos
sin
sin
sincos
sin
coscos
sincos
cos
coscos
cos
sin
*
χγσ
γ
α
σ
γ
βα
χ
γσ
α
σ
βα
γ
γ
βα
χγ
χγ
γ
−
+
+
+
−=
−+
+
+
+
=
−−
−
=
==
==
=
SOLO Three Degrees of Freedom Model in Earth Atmosphere
173. 02/28/15
173
(a) Spherical, Rotating Earth (Ω ≠ 0)
(b) Spherical, Non-Rotating Earth (Ω = 0)
(c) Flat Earth
0→Ω
( ) ( )
( ) ( ) ( )( )
( )
( ) ( ) ( )( )
( )
( ) ( )( )
( ) ( ) χ
γ
χγ
χγσ
γ
α
σ
γ
βα
χ
χγγ
χγσ
α
σ
βα
γ
χγγ
γ
βα
χγ
χγ
γ
sincossin
cos
sincoscostan2
tansincossin
cos
sin
cos
cos
sincos
cossinsincoscoscos
coscos2coscos
sin
sin
sincos
sinsincoscossincos
sin
coscos
sincos
cos
coscos
cos
sin
2
2
2
*
LatLat
V
R
LatLat
Lat
R
V
Vm
LT
Vm
CT
LatLatLat
V
R
Lat
V
g
R
V
Vm
LT
Vm
CT
LatLatLatR
ag
m
DT
V
R
V
R
V
td
Latd
LatR
V
LatR
V
td
Longd
V
td
Rd
xWW
E
N
Ω
+
−Ω−
−
+
+
+
−=
+
Ω
+
Ω+
−+
+
+
+
=
−Ω+
−−
−
=
==
==
=
( ) ( )
( )Lat
R
V
Vm
LT
Vm
CT
V
g
R
V
Vm
LT
Vm
CT
ag
m
DT
V
R
V
R
V
td
Latd
LatR
V
LatR
V
td
Longd
V
td
Rd
xWW
E
N
tansincossin
cos
sin
cos
cos
sincos
coscos
sin
sin
sincos
sin
coscos
sincos
cos
coscos
cos
sin
*
χγσ
γ
α
σ
γ
βα
χ
γσ
α
σ
βα
γ
γ
βα
χγ
χγ
γ
−
+
+
+
−=
−+
+
+
+
=
−−
−
=
==
==
=
σ
γ
α
σ
γ
βα
χ
γσ
α
σ
βα
γ
γ
βα
γ
ξγ
ξγ
sin
cos
sin
cos
cos
sincos
coscos
sin
sin
sincos
sin
coscos
sin
sincos
coscos
Vm
LT
Vm
CT
V
g
Vm
LT
Vm
CT
g
m
DT
V
Vz
Vy
Vx
E
E
E
+
+
+
−=
−
+
+
+
=
−
−
=
=
=
=
SOLO
∞→R
Three Degrees of Freedom Model in Earth Atmosphere
Return to Table of Content
174. 174
References
SOLO
Miele, A., “Flight Mechanics , Theory of Flight Paths, Vol I”, Addison Wesley,
1962
Aircraft Flight Performance
J.D. Anderson, Jr., “Introduction to Flight”, McGraw Hill, 1978, Ch. 6, “Elements
of Airplane Performance”
A. Filippone, “Flight Performance of Fixed and Rotary Wing Aircraft”,
Elsevier, 2006
M. Saarlas, “Aircraft Performance”, John Wiley & Sons, 2007
Stengel, MAE 331, Aircraft Flight Dynamics, Princeton University
J.D. Anderson, Jr., “Aircraft Performance and Design”, McGraw Hill, 1999
N.X. Vinh, “Flight Mechanics of High-Performance Aircraft”,
Cambridge University Press, 1993
F.O. Smetana, “Flight Vehicle Performance and Aerodynamic
Control”, AIAA Education Series, 2001
L. George, J.F. Vernet, “La Mécanique du Vol, Performances des
Avions et des Engines”, Librairie Polytechnique Ch. Béranger, 1960
L.J. Clancy, “Aerodynamics”, Pitman International Text, 1975
175. 175
Brandt, “Introduction to Aerodynamics – A Design Perspective”, Ch. 5 ,
Performance and Constraint Analysis
SOLO
Aircraft Flight Performance
J.D. Mattingly, W.H. Heiser, D.T. Pratt, “Aircraft Engine Design”, 2nd
Ed., AIAA
Education Series, 2002
Prof. Earll Murman, “Introduction to Aircraft Performance and Static Stability”,
September 18, 2003
Naval Air Training Command, “Air Combat Maneuvering”, CNATRA P-1289
(Rev. 08-09)
Patrick Le Blaye, “Agility: Definitions, Basic Concepts, History”, ONERA
Randal K. Liefer, John Valasek, David P. Eggold, “Fighter Aircraft Metrics,
Research , and Test”, Phase I Report, KU-FRL-831-2
References (continue – 1)
B. N. Pamadi, “Performance, Stability, Dynamics, and Control of Airplanes”,
AIAA Educational Series, 1998, Ch. 2 , Aircraft Performance
L.E. Miller, P.G. Koch, “Aircraft Flight Performance”, July 1978, AD-A018 547,
AFFDL-TR-75-89
176. 176
Courtland_D._Perkins,_Robert_E._Hage, “Airplane Performance Stability and
Control”, John Wiley & Sons, 1949
SOLO
Asselin, M., “Introduction to Aircraft Aerodynamics”, AIAA Education Series, 1997
Aircraft Flight Performance
References (continue – 2)
Donald R. Crawford, “A Practical Guide to Airplane Performance and Design”,
Crawford Aviation, 1981
Francis J. Hale, “ Introduction to aircraft performance, Selection and
Design”, John Wiley & Sons, 1984
J. Russell, ‘Performance and Stability of Aircraft“, Butterworth-Heinemann, 1996
Jan Roskam, C. T. Lan, “Airplane Aerodynamics and Performance”,
DARcorporation, 1997
Nono Le Rouje, “Performances of light aircraft”, AIAA, 1999
Peter J. Swatton, “Aircraft performance theory for Pilots”, Blackwell Science,
2000
S. K. Ojha, “Flight Performance of Aircraft “, AIAA, 1995
W. Austyn Mair, David L._Birdsall, “Aircraft Performance”,
Cambridge University Press, 1992
177. 177
SOLO
E.S. Rutowski, “Energy Approach to the General Aircraft Performance Problem”, Journal of
the Aeronautical Sciences, March 1954, pp. 187-195
Aircraft Flight Performance
References (continue – 3)
A.E. Bryson, Jr., “Applications of Optimal Control Theory in Aerospace Engineering”,
Journal of Spacecraft and Rockets, Vol. 4, No.5, May 1967, pp. 553
W.C. Hoffman, A.E. Bryson, Jr., “A Study of Techniques for Real-Time, On-Line Optimum
Flight Path Control”, Aerospace System Inc., ASI-TR-73-21, January 1973, AD 758799
A.E. Bryson, Jr., “A Study of Techniques for Real-Time, On-Line Optimum Flight Path
Control. Algorithms for Three-Dimensional Minimum-Time Flight Paths with Two State
Variables”, AD-A008 985, December 1974
M.G. Parsons, A.E. Bryson, Jr., W.C. Hoffman, “Long-Range Energy-State
Maneuvers for Minimum Time to Specified Terminal Conditions”, Journal of
Optimization Theory and Applications, Vol.17, No. 5-6, Dec 1975, pp. 447-463
A.E. Bryson, Jr., M.N, Desai, W.C. Hoffman, “Energy-State Approximation in Performance
Optimization of Supersonic Aircraft”, Journal of Aircraft, Vol.6, No. 6, Nov-Dec 1969, pp.
481-488
178. 178
SOLO
Aircraft Flight Performance
References (continue – 4)
Solo Hermelin Presentations http://www.solohermelin.com
• Aerodynamics Folder
• Propulsion Folder
• Aircraft Systems Folder
Return to Table of Content
179. 179
SOLO
Technion
Israeli Institute of Technology
1964 – 1968 BSc EE
1968 – 1971 MSc EE
Israeli Air Force
1970 – 1974
RAFAEL
Israeli Armament Development Authority
1974 –
Stanford University
1983 – 1986 PhD AA
185. 185
Ray Whitford, “Design for Air Combat”
R.W. Pratt, Ed., “Flight Control Systems, Practical issues in design and implementation”,
AIAA Publication, 2000
“Introduction to the Aerodynamics of Flight”, NASA History Office, SP-367, Talay, 1975
J.D. Anderson, Jr., “Aircraft Performance and Design”, McGraw Hill, 1999
John D._Anderson, “Fundamentals_of_Aerodynamics”, McGraw-Hill, 3th Ed., 1984, 1991, 2001
John D._Anderson, “Fundamentals_of_Aerodynamics”, McGraw-Hill, 3th Ed., 1984, 1991, 2001
John D._Anderson, “Fundamentals_of_Aerodynamics”, McGraw-Hill, 3th Ed., 1984, 1991, 2001
John D._Anderson, “Fundamentals_of_Aerodynamics”, McGraw-Hill, 3th Ed., 1984, 1991, 2001, pp.612-619
John D._Anderson, “Fundamentals_of_Aerodynamics”, McGraw-Hill, 3th Ed., 1984, 1991, 2001, pp.612-619
E. Torenbeek, H. Wittenberg, “Flight Physics, Essentials of Aeronautical Disciplines and Technology, with Historical Notes”, Springer, 2009, § 5.9, “Propeller Performance”
Asselin, M., “Introduction to Aircraft Performance”, AIAA Education Series, 1997
E. Torenbeek, H. Wittenberg, “Flight Physics, Essentials of Aeronautical Disciplines and Technology, with Historical Notes”, Springer, 2009, § 5.9, “Propeller Performance”,
Asselin, M., “Introduction to Aircraft Performance”, AIAA Education Series, 1997
L. Sankar, “Helicopter Aerodynamics and Performance”,
E. Torenbeek, H. Wittenberg, “Flight Physics, Essentials of Aeronautical Disciplines and Technology, with Historical Notes”, Springer, 2009, § 5.9, “Propeller Performance”,
Asselin, M., “Introduction to Aircraft Performance”, AIAA Education Series, 1997
Richard Shiu Wing Cheung , “Numerical Prediction of Propeller Performance by Vertex Lattice Method ”, UTIAS Technical Note No. 265 CN ISSN 0082-5263, 1987
L. Sankar, “Helicopter Aerodynamics and Performance”,
E. Torenbeek, H. Wittenberg, “Flight Physics, Essentials of Aeronautical Disciplines and Technology, with Historical Notes”, Springer, 2009, § 5.9, “Propeller Performance”,
Asselin, M., “Introduction to Aircraft Performance”, AIAA Education Series, 1997
Richard Shiu Wing Cheung , “Numerical Prediction of Propeller Performance by Vertex Lattice Method ”, UTIAS Technical Note No. 265 CN ISSN 0082-5263, 1987
L. Sankar, “Helicopter Aerodynamics and Performance”,
E. Torenbeek, H. Wittenberg, “Flight Physics, Essentials of Aeronautical Disciplines and Technology, with Historical Notes”, Springer, 2009, § 5.9, “Propeller Performance”,
Asselin, M., “Introduction to Aircraft Performance”, AIAA Education Series, 1997
Richard Shiu Wing Cheung , “Numerical Prediction of Propeller Performance by Vertex Lattice Method ”, UTIAS Technical Note No. 265 CN ISSN 0082-5263, 1987
L. Sankar, “Helicopter Aerodynamics and Performance”,
E. Torenbeek, H. Wittenberg, “Flight Physics, Essentials of Aeronautical Disciplines and Technology, with Historical Notes”, Springer, 2009, § 5.9, “Propeller Performance”,
Asselin, M., “Introduction to Aircraft Performance”, AIAA Education Series, 1997
Asselin, M., “Introduction to Aircraft Performance”, AIAA Education Series, 1997
E. Torenbeek, H. Wittenberg, “Flight Physics, Essentials of Aeronautical Disciplines and Technology, with Historical Notes”, Springer, 2009, § 5.9, “Propeller Performance”,
E. Torenbeek, H. Wittenberg, “Flight Physics, Essentials of Aeronautical Disciplines and Technology, with Historical Notes”, Springer, 2009, § 5.9, “Propeller Performance”,
E. Torenbeek, H. Wittenberg, “Flight Physics, Essentials of Aeronautical Disciplines and Technology, with Historical Notes”, Springer, 2009, § 5.9, “Propeller Performance”,
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Stengel, MAE331, Lecture 6
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