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.
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.
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.
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.
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.
This seminar gives idea about spacecraft propulsion i.e., actually what are different latest modes of propulsion are used in space agency and also the introduction of combustion of propellants.
This is the presentation on flow past an airfoil . An airfoil-shaped body moving through a fluid produces an aerodynamic force. The component of this force perpendicular to the direction of motion is called lift. The component parallel to the direction of motion is called drag. Subsonic flight airfoils have a characteristic shape with a rounded leading edge, followed by a sharp trailing edge, often with a symmetric curvature of upper and lower surfaces.
Airplane (fixed wing aircraft) configuration and various parts | Flight Mecha...Age of Aerospace
For Video Lecture of this presentation: https://youtu.be/uD_qWvTZEhY
The topics covered in this session are, Airplane (fixed wing aircraft) configurations and various parts of airplane. A detailed list of airplane configuration is discussed with general insight about airplane parts.
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
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.
Atmosphere: Properties and Standard Atmosphere | Flight Mechanics | GATE Aero...Age of Aerospace
For Video Lecture of this presentation: https://youtu.be/DqaoNt0LoIE
The topics covered in this session are, Properties of Atmosphere, International Standard Atmosphere (ISA) definition and derivation, ISA Chart. The formula for obtaining ISA Chartar completely derived from basic equations.
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
Characteristics of single pump and pumps in series and parallel use of indust...TOPENGINEERINGSOLUTIONS
This is a water engineering assignment on Characteristics of single pump and pumps in series and parallel
(Use of Industry Standard Software)
Module Code: NG2S106, Module Title: Water Engineering
ME438 Aerodynamics is offered by Dr. Bilal Siddiqui to senior mechanical engineering undergraduates at DHA Suffa University. This lecture set is about prediction of lift on thin cambered airfoils.
The term Diffraction has been defined by Sommerfield as any deviation of light rays from rectilinear paths which cannot be interpreted as reflection or refraction.
For comments please connect me at solo.hermelin@gmail.com.
For more presentations on different subjects visit my website at http://www.solohermelin.com. This presentation is in the Optics folder.
Presents the Tracking methods of moving targets by sensors (radar, electro optics,..).
For comments please contact me at solo.hermelin@gmail.com.
For more presentations visit my website at http://www.solohermelin.com.
I recommend to view this presentation on my website at RADAR folder, Tracking Systems subfolder.
This seminar gives idea about spacecraft propulsion i.e., actually what are different latest modes of propulsion are used in space agency and also the introduction of combustion of propellants.
This is the presentation on flow past an airfoil . An airfoil-shaped body moving through a fluid produces an aerodynamic force. The component of this force perpendicular to the direction of motion is called lift. The component parallel to the direction of motion is called drag. Subsonic flight airfoils have a characteristic shape with a rounded leading edge, followed by a sharp trailing edge, often with a symmetric curvature of upper and lower surfaces.
Airplane (fixed wing aircraft) configuration and various parts | Flight Mecha...Age of Aerospace
For Video Lecture of this presentation: https://youtu.be/uD_qWvTZEhY
The topics covered in this session are, Airplane (fixed wing aircraft) configurations and various parts of airplane. A detailed list of airplane configuration is discussed with general insight about airplane parts.
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
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.
Atmosphere: Properties and Standard Atmosphere | Flight Mechanics | GATE Aero...Age of Aerospace
For Video Lecture of this presentation: https://youtu.be/DqaoNt0LoIE
The topics covered in this session are, Properties of Atmosphere, International Standard Atmosphere (ISA) definition and derivation, ISA Chart. The formula for obtaining ISA Chartar completely derived from basic equations.
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
Characteristics of single pump and pumps in series and parallel use of indust...TOPENGINEERINGSOLUTIONS
This is a water engineering assignment on Characteristics of single pump and pumps in series and parallel
(Use of Industry Standard Software)
Module Code: NG2S106, Module Title: Water Engineering
ME438 Aerodynamics is offered by Dr. Bilal Siddiqui to senior mechanical engineering undergraduates at DHA Suffa University. This lecture set is about prediction of lift on thin cambered airfoils.
The term Diffraction has been defined by Sommerfield as any deviation of light rays from rectilinear paths which cannot be interpreted as reflection or refraction.
For comments please connect me at solo.hermelin@gmail.com.
For more presentations on different subjects visit my website at http://www.solohermelin.com. This presentation is in the Optics folder.
Presents the Tracking methods of moving targets by sensors (radar, electro optics,..).
For comments please contact me at solo.hermelin@gmail.com.
For more presentations visit my website at http://www.solohermelin.com.
I recommend to view this presentation on my website at RADAR folder, Tracking Systems subfolder.
Describes the general solutions of Electromagnetic Maxwell Equations.
Intended or Graduate Students in Science (math, physics, engineering) with previous knowledge in electromagnetics.
Please send me comments and suggestions for improvements to solo.hermelin@gmail.com.
More presentations can be found in my website at http://www.solohermelin.com.
Describes the Color Theory History.
Please send comments and suggestions for improvements to solo.hermelin@gmail.com. Thanks.
For more presentations on other subjects please visit my website at http://www.solohermelin.com.
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.
Calibrating a CFD canopy model with the EC1 vertical profiles of mean wind sp...Stephane Meteodyn
For some projects, applying the basic rules of EC1 is not sufficient, and it is required to get a more accurate estimation of the wind speed on the construction site. This can be done by using computational fluid dynamics codes which have the advantage, both to take into account of the terrain inhomogeneity and to calculate 3D orographic effects. In this way, the orography and roughness effects are coupled as they are in the real world. However, applying CFD computations must be in coherence with EC1 code. Then it is necessary to calibrate the ground friction for low roughness terrains as well as the drag force and turbulence production in case of high roughness lengths due to the presence of a canopy (forests or built areas). That is the condition for such methods to be commonly used and agreed by Building Control Officers. In this mind, TopoWind has been developed especially for wind design applications and can be a very useful, practical and objective tool for wind design engineers. The canopy model implemented in TopoWind has been calibrated in order to get the mean wind and turbulence profiles as defined in the EC1 for standard terrains. In this way, TopoWind computations satisfy the continuity between the EC1 values for homogeneous terrains and the more complex cases involving inhomogeneous roughness or orographic effects
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
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.
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
Comparing Evolved Extractive Text Summary Scores of Bidirectional Encoder Rep...University of Maribor
Slides from:
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Track: Artificial Intelligence
https://www.etran.rs/2024/en/home-english/
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...Ana Luísa Pinho
Functional Magnetic Resonance Imaging (fMRI) provides means to characterize brain activations in response to behavior. However, cognitive neuroscience has been limited to group-level effects referring to the performance of specific tasks. To obtain the functional profile of elementary cognitive mechanisms, the combination of brain responses to many tasks is required. Yet, to date, both structural atlases and parcellation-based activations do not fully account for cognitive function and still present several limitations. Further, they do not adapt overall to individual characteristics. In this talk, I will give an account of deep-behavioral phenotyping strategies, namely data-driven methods in large task-fMRI datasets, to optimize functional brain-data collection and improve inference of effects-of-interest related to mental processes. Key to this approach is the employment of fast multi-functional paradigms rich on features that can be well parametrized and, consequently, facilitate the creation of psycho-physiological constructs to be modelled with imaging data. Particular emphasis will be given to music stimuli when studying high-order cognitive mechanisms, due to their ecological nature and quality to enable complex behavior compounded by discrete entities. I will also discuss how deep-behavioral phenotyping and individualized models applied to neuroimaging data can better account for the subject-specific organization of domain-general cognitive systems in the human brain. Finally, the accumulation of functional brain signatures brings the possibility to clarify relationships among tasks and create a univocal link between brain systems and mental functions through: (1) the development of ontologies proposing an organization of cognitive processes; and (2) brain-network taxonomies describing functional specialization. To this end, tools to improve commensurability in cognitive science are necessary, such as public repositories, ontology-based platforms and automated meta-analysis tools. I will thus discuss some brain-atlasing resources currently under development, and their applicability in cognitive as well as clinical neuroscience.
This presentation explores a brief idea about the structural and functional attributes of nucleotides, the structure and function of genetic materials along with the impact of UV rays and pH upon them.
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
2. 2
Table of Content
AERODYNAMICS
Earth Atmosphere
Mathematical Notations
SOLO
Basic Laws in Fluid Dynamics
Conservation of Mass (C.M.)
Conservation of Linear Momentum (C.L.M.)
Conservation of Moment-of-Momentum (C.M.M.)
The First Law of Thermodynamics
The Second Law of Thermodynamics and Entropy Production
Constitutive Relations for Gases
Newtonian Fluid Definitions – Navier–Stokes Equations
State Equation
Thermally Perfect Gas and Calorically Perfect Gas
Boundary Conditions
Dimensionless Equations
Boundary Layer and Reynolds Number
3. 3
Table of Content (continue – 1)
AERODYNAMICS
SOLO
Circulation
Biot-Savart Formula
Helmholtz Vortex Theorems
2-D Inviscid Incompressible Flow
Stream Function ψ, Velocity Potential φ in 2-D Incompressible
Irrotational Flow
Aerodynamic Forces and Moments
Blasius Theorem
Kutta Condition
Kutta-Joukovsky Theorem
Joukovsky Airfoils
Theodorsen Airfoil Design Method
Profile Theory by the Method of Singularities
Airfoil Design
Flow Description
Streamlines, Streaklines, and Pathlines
4. 4
Table of Content (continue – 2)
AERODYNAMICS
SOLO
Lifting-Line Theory
Subsonic Incompressible Flow (ρ∞ = const.) about Wings
of Finite Span (AR < ∞)
3D Lifting-Surface Theory through Vortex Lattice Method (VLM)
Incompressible Potential Flow Using Panel Methods
Wing Configurations
Wing Parameters
References
5. 5
Table of Content (continue – 3)
AERODYNAMICS
SOLO
Linearized Flow Equations
Cylindrical Coordinates
Small Perturbation Flow
Applications: Nonsteady One-Dimensional Flow
Applications: Two Dimensional Flow
Shock & Expansion Waves
Shock Wave Definition
Normal Shock Wave
Oblique Shock Wave
Prandtl-Meyer Expansion Waves
Movement of Shocks with Increasing Mach Number
Drag Variation with Mach Number
Swept Wings Drag Variation
Variation of Aerodynamic Efficiency with Mach Number
AERO
6. 6
Table of Content (continue – 4)
AERODYNAMICS
SOLO
Analytic Theory and CFD
Transonic Area Rule
Aircraft Flight Control
AERO
9. 9
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
12. The Earth Atmosphere might be described as a Thermodynamic
Medium in a Gravitational Field and in Hydrostatic Equilibrium
set by Solar Radiation. Since Solar Radiation and Atmospheric
Reradiation varies diurnally and annually and with latitude and
longitude, the Standard Atmosphere is only an approximation.
SOLO
12
The purpose of the Standard Atmosphere has been defined by
the World Metheorological Organization (WMO).
The accepted standards are the COESA (Committee on
Extension to the Standard Atmosphere) US Standard Atmosphere
1962, updated by US Standard Atmosphere 1976.
Earth Atmosphere
13. The basic variables representing the thermodynamics state of
the gas are the Density, ρ, Temperature, T and Pressure, p.
SOLO
13
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
14. 14
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
16. 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
16
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
17. 17
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
18. 18
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
19. 19
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
20. 20
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
21. 21
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
22. 22
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).
Earth AtmosphereSOLO
27. 27
Winds
Winds represents the relative motion of the Atmosphere
Earth Atmosphere
Although in the standard atmosphere the air is
motionless with respect to the Earth, it is known that
the air mass through which an airplane flies is
constantly in a state of motion with respect to the
surface of the Earth. Its motion is variable both in
time and space and is exceedingly complex. The
motion may be divided into two classes: (1) large-
scale motions and (2) small-scale motions. Large-
scale motions of the atmosphere (or winds) affect
the navigation and the performance of an aircraft.
SOLO
Return to Table of Content
28. 28
FLUID DYNAMICS
1. MATHEMATICAL NOTATIONS
VECTOR NOTATION CARTESIAN TENSOR NOTATION
1.1 VECTOR
1.2 SCALAR PRODUCT
1.3 VECTOR PRODUCT
u kk = 1 2 3, ,
u u e u e u e= + +1 1 2 2 3 3
u v u v u v u v⋅ = + +1 1 2 2 3 3 u v kk k = 1 2 3, ,
u v
u u
u u
u u
v
v
v
× =
−
−
−
0
0
0
3 2
3 1
2 1
1
2
3
=
−
+
±
=−=
ji
permutjiodd
permutjieven
CevittaLevi
vu
ij
jiij
0
.,
.,
1
ε
ε
SOLO
29. 29
FLUID DYNAMICS
1. MATHEMATICAL NOTATIONS (CONTINUE)
VECTOR NOTATION CARTESIAN TENSOR NOTATION
1.5 ROTOR OF A VECTOR
1.4 DIVERGENCE OF A VECTOR
1.6 GRADIENT OF A SCALAR
∇⋅ = + +
u
u
x
u
x
u
x
∂
∂
∂
∂
∂
∂
1
1
2
2
3
3 i
i
x
u
∂
∂
∇× = −
+ −
+ −
u
u
x
u
x
e
u
x
u
x
e
u
x
u
x
e
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
3
2
2
3
1
1
3
3
1
2
1
2
2
1
3
u u
u
u u×∇× =∇
− ⋅∇
2
2
∂
∂
∂
∂
u
x
u
x
i
k
k
i
−
i
k
j
k
i
i
x
u
u
x
u
u
∂
∂
∂
∂
−
∇ = + +
=
φ
∂ φ
∂
∂ φ
∂
∂ φ
∂
∂ φ
∂
∂ φ
∂
∂ φ
∂
x
e
x
e
x
e
x x x
1
1
2
2
31
3
1 2 3
∂ φ
∂ xk
SOLO
30. 30
FLUID DYNAMICS
1.MATHEMATICAL NOTATIONS (CONTINUE)
VECTOR NOTATION CARTESIAN TENSOR NOTATION
1.7GRADIENT OF A VECTOR
∇ = ∇ + ∇ + ∇
u u e u e u e1 1 2 2 3 3
∇ =
u
u
x
u
x
u
x
u
x
u
x
u
x
u
x
u
x
u
x
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
1
1
1
2
1
3
2
1
2
2
2
3
3
1
3
2
3
3
∇ =
+ + +
+ + +
+ + +
u
u
x
u
x
u
x
u
x
u
x
u
x
u
x
u
x
u
x
u
x
u
x
u
x
u
x
u
x
u
x
u
x
u
x
u
x
D
ik
1
2
1
1
1
1
1
2
2
1
1
3
3
1
2
1
1
2
2
2
2
2
2
3
3
1
3
1
1
3
3
2
2
3
3
3
3
3
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
+
ik
x
u
x
u
x
u
x
u
x
u
x
u
x
u
x
u
x
u
x
u
x
u
x
u
Ω
−−
−−
−−
+
0
0
0
2
1
3
2
2
3
3
1
1
3
1
3
3
2
2
1
1
2
1
3
3
1
1
2
2
1
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
u
x
i
k
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
u
x
u
x
u
x
u
x
u
x
i
k
i
k
k
i
i
k
k
i
= +
+ −
1
2
1
2
D
u
x
u
x
ik
i
k
k
i
= +
∆ 1
2
∂
∂
∂
∂
Ω
∆
ik
i
k
k
i
u
x
u
x
= −
1
2
∂
∂
∂
∂
SOLO
31. 31
FLUID DYNAMICS
1. MATHEMATICAL NOTATIONS (CONTINUE)
VECTOR NOTATION CARTESIAN TENSOR NOTATION
1.8 GAUSS’ THEOREMS
ds
A
V
∇⋅
A analytic in V
↓ = =
A C C const vectorη .
( ) ∫∫ ∫∫∫∇=
S V
dvsdGAUSS ηη
2
∇η analytic in V ∫∫ ∫∫∫=
S k
k
V
dv
s
ds
∂
η∂
η
SOLO
Johann Carl Friederich Gauss
1777-1855
( ) ∫∫ ∫∫∫ ⋅∇=⋅
S
V
dvAsdAGAUSS
1
∫∫ ∫∫∫=
S k
k
kk
V
dv
x
A
dsA
∂
∂
32. 32
FLUID DYNAMICS
1.MATHEMATICAL NOTATIONS (CONTINUE)
VECTOR NOTATION CARTESIAN TENSOR NOTATION
1.8GAUSS’ THEOREMS (CONTINUE)
( ) ( ) ( )∫∫ ∫∫∫ ⋅∇=⋅
S V
dvAsdAGAUSS
ηη3
( )= ⋅∇ + ∇⋅∫∫∫
A A dvη η
η∇⋅∇ ,A
analytic inV
( )η
∂ η
∂
A ds
A
x
dv
V
k k
k
kS
= ∫∫∫∫∫
∫∫∫
+=
V k
k
k
k
x
A
x
A
∂
∂
η
∂
η∂
↓ = + +
B e e eη η η1 1 2 2 3 3
( ) ( ) ( )[ ]∫∫ ∫∫∫ ⋅∇+∇⋅=⋅
S V
dvABBAsdABGAUSS
4 B A ds A
B
x
B
A
x
dv
V
i k k k
i
k
i
k
kS
= +
∫∫∫∫∫
∂
∂
∂
∂
∇ ×
A analytic inV( ) ∫∫ ∫∫∫ ×∇=×
S V
dvAAsdGAUSS
5 ( )ds A ds A
A
x
A
x
dv
V
i j j i
j
i
i
jS
− = −
∫∫∫∫∫
∂
∂
∂
∂
SOLO
33. 33
FLUID DYNAMICS
1.MATHEMATICAL NOTATIONS (CONTINUE)
VECTOR NOTATION CARTESIAN TENSOR NOTATION
1.9STOCKES’ THEOREM
A d r A d s
C S
⋅ = ∇ × ⋅∫ ∫∫ ∇ ×
A analytic on S
A d r
A
x
A
x
d si i
C
j
i
i
j
k
S
∫ ∫∫= −
∂
∂
∂
∂
Gauss’ and Stokes’ Theorems are generalizations of the
Fundamental Theorem Of CALCULUS
( )A b A a
d A x
d x
d x
a
b
( ) ( )− = ∫
George Stokes
1819-1903
SOLO
34. SOLO
Variational Principles of Hydrodynamics
Joseph-Louis
Lagrange
1736-1813
Leonhard Euler
1707-1783
FIXED IN SPACE
(CONSTANT VOLUME)
EULER
LAGRANGE
MOVING WITH THE FLUID
(CONSTANT MASS)
1e
3
e
2
e
u
The phenomena considered in Hydrodynamics are macroscopic and the atomic or
molecular nature of the fluid is neglected. The fluid is regarded as a continuous
medium. Any small volume element is always supposed to be so large that it still
contains a large number of molecules.
There are two representations normally employed in the study of Hydrodynamics:
- Euler representation: The fluid passes through a Constant Volume Fixed in
Space
- Lagrange representation: The fluid Mass is kept constant during its motion in
Space.
Hydrodynamic Field
35. SOLO
Variational Principles of Hydrodynamics
Material Derivatives (M.D.)
Vector Notation Cartesian Tensor Notation
1
e
2e
3
e
r
u
b
rd
( ) Frddt
t
F
trFd
∇⋅+=
∂
∂
,
( )
d
dt
F r t
F
t
dr
dt
F
, = + ⋅∇
∂
∂
( )
d
dt
F r t
F
t
b F
b
, = + ⋅∇
∂
∂
rdanyfor
( )d F r t
F
t
dt d r
F
x
i k
i
k
i
k
, = +
∂
∂
∂
∂
( )
d
dt
F r t
F
t
d r
dt
F
x
i k
i k i
k
, = +
∂
∂
∂
∂
( )
d
dt
F r t
F
t
b
F
xb
i k
i
k
i
k
, = +
∂
∂
∂
∂
vectoranybbtd
rd
=
( ) Fu
t
F
F
tD
D
trF
td
d
u
∇⋅+=≡
∂
∂
,
( )
k
i
k
i
ki
u
x
F
u
t
F
F
tD
D
trF
td
d
∂
∂
∂
∂
+=≡,
velocityfluiduu
td
rd
If
=
uu
u
t
u
uu
t
u
u
tD
D
×∇×−
∇+=
∇⋅+=
2
2
∂
∂
∂
∂
⋅−⋅−
+=
+=
k
i
k
i
j
j
j
i
i
k
i
k
i
i
x
u
u
x
u
u
u
xt
u
x
u
u
t
u
u
tD
D
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
2
2
1
Acceleration Of The Fluid
1
e
2
e
3
e
r
u
duu +
dr
Material Derivatives = = Derivative Along A Fluid Path (Streamline)tD
D
Hydrodynamic Field
36. 36
FLUID DYNAMICS
1. MATHEMATICAL NOTATIONS (CONTINUE)
VECTOR NOTATION CARTESIAN TENSOR NOTATION
1.10 MATERIAL DERIVATIVES (CONTINUE)
d u
u
t
dt dr u
= + ⋅∇
∂
∂
du
u
t
dt dx
u
x
i
i
k
i
k
= + ⋅
∂
∂
∂
∂
rdrdDtd
t
u
xd
xd
xd
x
u
x
u
x
u
x
u
x
u
x
u
x
u
x
u
x
u
t
u
t
u
t
u
ud
ud
ud
ikik
Ω++=
=
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
3
2
1
3
3
2
3
1
3
3
2
2
2
1
2
3
1
2
1
1
1
3
2
1
3
2
1
d u
u
t
d t
u
x
u
x
d x
u
x
u
x
d x
i
i
Translation
i
k
k
i
Dilation
k
i
k
k
i
Rotation
k
= +
+ +
+ −
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
1
2
1
2
( )
( )
( )
( )[ ] Dilationrduu
rdurdu
urdrdurdu
rdurdurdD
T
u
u
ik
⇒⋅∇+∇=
⋅∇+⋅∇=
∇⋅−⋅∇+⋅∇=
××∇−⋅∇=
2
1
2
1
2
1
2
1
2
1
2
1
( )Ωik dr u dr Rotation
= ∇ × × ⇒
1
2
SOLO
37. 37
REYNOLDS’ TRANSPORT THEOREM
-any system of coordinatesOxyz
- any continuous and differentiable
functions in
( ) ( )trtr OO ,,, ,,
ηχ
( )tandrO,
( )trO ,,
ρ - flow density at point
and time t
Or,
SOLO
- mass flow through the element .mdsdVS
=⋅− ,ρ sd
- any control volume, changing shape, bounded by a closed surface S(t)v (t)
- flow velocity, relative to O, at point and time t( )trV OOflow ,,,
Or,
- position and velocity, relative to O, of an element of surface, part of the
control surface S(t).
OSOS Vr ,, ,
- area of the opening i, in the control surface S(t).iopenS
- gradient operator in O frame.O,∇
- flow relative to the opening i, in the control surface S(t).OSiOflowSi VVV ,,,
−=
- differential of any vector , in O frame.
O
td
d ζ
ζ
FLUID DYNAMICS
38. 38
Start with LEIBNIZ THEOREM from CALCULUS:
( ) ( )
ChangeBoundariesthetodueChange
tb
ta
tb
ta td
tad
ttaf
td
tbd
ttbfdx
t
txf
dxtxf
td
d
LEIBNITZ
−+= ∫∫ )),(()),((
),(
),(::
)(
)(
)(
)( ∂
∂
and generalized it for a 3 dimensional vector space on a volume v(t) bounded by the
surface S(t).
Using LEIBNIZ THEOREM followed by GAUSS THEOREM (GAUSS 4):
( ) ( )
( ) ( )
∫∫∫∫∫
⋅∇+∇⋅+=⋅+
→
=
tv
OSOOOSGAUSS
Opotolative
dsofMovement
thetodueChage
tS
OS
tv
O
LEIBNITZ
O
tv
vdVV
t
GAUSS
sdVvd
t
vd
td
d
,,,,)4(
intRe
)(
,
χχ
∂
χ∂
χ
∂
χ∂
χ
This is REYNOLDS’ TRANSPORT THEOREM
OSBORNE
REYNOLDS
1842-1912
SOLO
GOTTFRIED WILHELM
von LEIBNIZ
1646-1716
REYNOLDS’ TRANSPORT THEOREM
FLUID DYNAMICS
1. MATHEMATICAL NOTATIONS (CONTINUE)
39. 39
FLUID DYNAMICS
1. MATHEMATICAL NOTATIONS (CONTINUE)
1.11 REYNOLDS’ TRANSPORT THEOREM (CONTINUE)
VECTOR NOTATION CARTESIAN TENSOR NOTATION
( )
∫∫∫
∫∫∫∫∫∫∫∫
⋅∇+∇⋅+=
⋅+=
)(
,,,,)4(
,
)()()(
tv
OSOOOS
O
GAUSS
OS
tStv
O
LEIBNITZ
O
tv
vdVV
t
GAUSS
sdVvd
t
vd
td
d
χχ
∂
χ∂
χ
∂
χ∂
χ
∫∫∫
∫∫∫∫∫∫∫∫
++=
+=
)(
,
,)4(
,
)()()(
tv k
kOS
i
k
i
kOS
i
GAUSS
kkOS
tS
i
tv
i
LEIBNITZ
tv
i
vd
x
V
x
V
t
GAUSS
sdVvd
t
vd
td
d
∂
∂
χ
∂
χ∂
∂
χ∂
χ
∂
χ∂
χ
SOLO
40. 40
FLUID DYNAMICS
1. MATHEMATICAL NOTATIONS (CONTINUE)
1.11 REYNOLDS’ TRANSPORT THEOREM (CONTINUE)
VECTOR NOTATION CARTESIAN TENSOR NOTATION
O
OOS
td
Rd
uV
== ,,
CASE 1 (CONTROL VOLUME vF ATTACHED TO THE FLUID)
kkOS
uV =,
( )
∫∫∫
∫∫∫∫∫∫∫∫
⋅∇+∇⋅+=
⋅+=
)(
,,,)4(
,
)()()(
tv
OOO
O
GAUSS
O
tStv
OO
tv
F
FFF
vduu
t
GAUSS
sduvd
t
vd
td
d
χχ
∂
χ∂
χ
∂
χ∂
χ
∫∫∫
∫∫∫∫∫∫∫∫
++=
+=
)(
)4(
)()()(
tv k
k
I
k
I
k
I
GAUSS
kK
tS
I
tv
I
tv
I
F
FFF
vd
x
u
x
u
t
GAUSS
sduvd
t
vd
td
d
∂
∂
χ
∂
χ∂
∂
χ∂
χ
∂
χ∂
χ
SOLO
41. 41
FLUID DYNAMICS
1. MATHEMATICAL NOTATIONS (CONTINUE)
1.11 REYNOLDS’ TRANSPORT THEOREM (CONTINUE)
VECTOR NOTATION CARTESIAN TENSOR NOTATION
1&,
== χkkOS
uV1&, == χuV OS
CASE 2 (CONTROL VOLUME vF ATTACHED TO THE FLUID AND )1=χ
∫∫∫∫∫∫∫∫ ⋅∇=⋅==
)(
,,
)(
,
)(
)(
tv
OO
tS
O
tv
F
FFF
vdusduvd
td
d
td
tvd
∫∫∫∫∫∫∫∫ ===
)()()(
)(
tv k
k
k
tS
k
tv
F
FFF
dv
x
u
dsudv
td
d
td
tvd
∂
∂
=⋅∇
→ td
tvd
tv
u F
F
tv
OO
F
)(
)(
1
lim0)(
,,
=
→ td
tvd
tvx
u F
F
tv
k
k
F
)(
)(
1
lim0)(∂
∂
EULER 1755
SOLO
42. 42
FLUID DYNAMICS
1. MATHEMATICAL NOTATIONS (CONTINUE)
1.11 REYNOLDS’ TRANSPORT THEOREM (CONTINUE)
VECTOR NOTATION CARTESIAN TENSOR NOTATION
CASE 3 (CONTROL VOLUME vF ATTACHED TO THE FLUID AND )
ρχ == &, kkOS uVρχ == &, uV OS
ρχ =
or, since this is true for any attached volume vF(t)
( )∫∫∫
∫∫∫∫∫ ∫∫∫
⋅∇+=
⋅+===
)(
,,
)(
,
)( )(
)(
0
tv
OO
tS
O
tv tv
F
FF F
vdu
t
sduvd
t
vd
td
d
td
tmd
ρ
∂
ρ∂
ρ
∂
ρ∂
ρ
( )∫∫∫
∫∫∫∫∫ ∫∫∫
+=
+===
)(
)()( )(
)(
0
tv
k
k
tS
kk
tv tv
F
FF F
vdu
xt
sduvd
t
dv
td
d
td
tmd
ρ
∂
∂
∂
ρ∂
ρ
∂
ρ∂
ρ
Because the Control Volume vF is attached to the fluid and they are not sources or sinks,
the mass is constant.
( ) OOOOOO uu
t
u
t
,,,,,,0
⋅∇+∇⋅+=⋅∇+= ρρ
∂
ρ∂
ρ
∂
ρ∂
( )
k
k
k
k
k
x
u
x
u
t
u
xt ∂
∂
ρ
∂
ρ∂
∂
ρ∂
ρ
∂
∂
∂
ρ∂
++=+=
0
SOLO
43. 43
FLUID DYNAMICS
1. MATHEMATICAL NOTATIONS (CONTINUE)
1.11 REYNOLDS’ TRANSPORT THEOREM (CONTINUE)
VECTOR NOTATION CARTESIAN TENSOR NOTATION
CASE 4 (CONTROL VOLUME WITH FIXED SHAPE C.V. )0,
=OS
V
Define
∫∫∫∫∫∫ =
.... VC
OO
VC
vd
t
vd
td
d
∂
χ∂
χ
∫∫∫∫∫∫ =
.... VC
i
VC
i vd
t
vd
td
d
∂
χ∂
χ
( ) ( ) ( )
χ ρ ηr t r t r t, , ,≡ ( ) ( ) ( )χ ρ ηi k k i kx t x t x t, , ,≡
( )∫∫
∫∫∫∫∫∫
⋅+
+=
)(
,
)()(
tS
OS
tv
OO
tv
sdV
vd
tt
vd
td
d
ηρ
∂
ρ∂
η
∂
η∂
ρηρ
k
tS
kOSi
tv
i
i
tv
i
sdV
vd
tt
vd
td
d
FF
∫∫
∫∫∫∫∫∫
+
+=
)(
,
)()(
ηρ
∂
ρ∂
η
∂
η∂
ρηρ
We have
but
( ) ( )OOOO
u
t
u
t
,,,,
0
ρη
∂
ρ∂
ηρ
∂
ρ∂
⋅∇−=⇒=⋅∇+
( ) ( )k
k
iik
k
u
xt
u
xt
ρ
∂
∂
η
∂
ρ∂
ηρ
∂
∂
∂
ρ∂
−=⇒=+ 0
CASE 5 ( ) ( ) ( )
χ ρ ηr t r t r t, , ,≡
SOLO
44. 44
FLUID DYNAMICS
1. MATHEMATICAL NOTATIONS (CONTINUE)
1.11 REYNOLDS’ TRANSPORT THEOREM (CONTINUE)
VECTOR NOTATION CARTESIAN TENSOR NOTATION
We have
( )
( )
( ) ( )[ ]
( )
( )[ ]∫∫∫∫∫=
∫∫
∫∫∫
∫∫
∫∫∫∫∫∫
⋅−+
⋅+
⋅∇+∇⋅−
∇⋅+=
⋅+
⋅∇−=
+
+
)(
,,
)(
4
.
)(
,
)(
,,,,,,
)(
,
)(
,,
)(
tS
OOS
tv
O
MDG
DerMat
GAUSS
tS
OS
tv
OOOOOO
O
tS
OS
tv
OO
OO
tv
sduVvd
tD
D
sdV
vduuu
t
sdV
vdu
t
vd
td
d
ρηρ
η
ρη
ρηηρη
∂
η∂
ρ
ρη
ρηρ
∂
η∂
ρη ( )
( )
( ) ( )
( )
( )[ ]∫∫∫∫∫=
∫∫
∫∫∫
∫∫
∫∫∫∫∫∫
−+
+
+−
+=
+
−=
+
+
)(
,
)(
4
.
)(
,
)(
)(
,
)()(
tS
kkkOSi
tv
i
MDG
DerMat
GAUSS
tS
kkOSi
tv k
k
i
k
i
k
k
i
k
i
tS
kkOSi
tv k
k
i
i
tv
i
sduVvd
tD
D
sdV
vd
x
u
x
u
x
u
t
sdV
vd
x
u
t
vd
td
d
ρηρ
η
ρη
∂
ρ∂
η
∂
η∂
ρ
∂
η∂
∂
η∂
ρ
ρη
∂
ρ∂
ηρ
∂
η∂
ρη
CASE 5 ( ) ( ) ( )
χ ρ ηr t r t r t, , ,≡
SOLO
45. 45
FLUID DYNAMICS
1. MATHEMATICAL NOTATIONS (CONTINUE)
1.11 REYNOLDS’ TRANSPORT THEOREM (CONTINUE)
VECTOR NOTATION CARTESIAN TENSOR NOTATION
REYNOLDS 1
( )[ ]
⋅−+= ∫∫∫∫∫
∫∫∫
)(
,,
)(
)(
tS
OOS
tv
O
O
tv
sduVvd
tD
D
vd
td
d
ρηρ
η
ρη
( )[ ]
−+= ∫∫∫∫∫
∫∫∫
)(
,
)(
)(
tS
kkkOSi
tv
i
tv
i
sduVvd
tD
D
dv
td
d
ρηρ
η
ρη
REYNOLDS 2
( )[ ]
=
⋅−+
∫∫∫
∫∫∫∫∫
)(
)(
,,
)(
tv
O
tS
OSO
O
tv
vd
tD
D
sdVuvd
td
d
ρ
η
ρηρη
( )[ ]
=
−+
∫∫∫
∫∫∫∫∫
)(
)(
,
)(
tv
i
tS
kkOSki
tv
i
vd
tD
D
sdVuvd
td
d
ρ
η
ρηρη
CASE 5 ( ) ( ) ( )
χ ρ ηr t r t r t, , ,≡
SOLO
46. 46
FLUID DYNAMICS
1. MATHEMATICAL NOTATIONS (CONTINUE)
1.11 REYNOLDS’ TRANSPORT THEOREM (CONTINUE)
VECTOR NOTATION CARTESIAN TENSOR NOTATION
REYNOLDS 3
CASE 1 (CONTROL VOLUME ATTACHED TO THE FLUID vF(t) )
kkOS
uV =,
∫∫∫∫∫∫ =
)()( tv
OO
tv FF
vd
tD
D
vd
td
d
ρ
η
ρη
∫∫∫∫∫∫ =
)()( tv
i
tv
i
FF
vd
tD
D
vd
td
d
ρ
η
ρη
SOLO
O
OOS
td
Rd
uV
== ,,
( ) ( ) ( )
χ ρ ηr t r t r t, , ,≡
CASE 4 (CONTROL VOLUME WITH FIXED SHAPE C.V. )0,
=OS
V
REYNOLDS 4
( )
⋅+= ∫∫∫∫∫
∫∫∫
..
,
..
..
SC
O
O
VC
VC
O
sduvd
td
d
vd
tD
D
ρηρη
ρ
η
( )
+= ∫∫∫∫∫
∫∫∫
....
..
SC
kki
VC
i
VC
i
sduvd
td
d
vd
tD
D
ρηρη
ρ
η
Return to Table of Content
47. 47
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS
THE FLUID DYNAMICS IS DESCRIBED BY THE FOLLOWING FIVE LAWS:
SOLO
(1) CONSERVATION OF MASS (C.M.)
(2) CONSERVATION OF LINEAR MOMENTUM (C.L.M.)
(3) CONSERVATION OF MOMENT OF MOMENTUM (C.M.M.)
(4) THE FIRST LAW OF THERMODYNAMICS
(5) THE SECOND LAW OF THERMODYNAMICS
Return to Table of Content
48. 48
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.1) CONSERVATION OF MASS (C.M.)
Control Volume attached to the fluid
(containing a constant mass m) bounded by
the Control Surface SF (t).
( )tvF
( )tr,
ρ ( )3
/mkgFlow density
SOLO
Because vF(t) is attached to the fluid and there are no sources or sinks in this volume,
the Conservation of Mass requires that:
d m t
d t
( )
= 0
( ) ( )trVtru OfluidO ,, ,,
= Flow Velocity relative to a predefined
Coordinate System O (Inertial or
Not-Inertial) ( )sm/
49. 49
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.1) CONSERVATION OF MASS (CONTINUE - 1)
VECTOR NOTATION CARTESIAN TENSOR NOTATION
d m t
d t
( )
= 0
( )∫∫∫=
∫∫∫∫∫ ∫∫∫
⋅∇+
⋅+===
)(
,,
1
)(
,
)( )(
)(
0
tv
OO
GAUSS
tS
O
tv tv
REYNOLDS
F
FF F
vdu
t
sduvd
t
dv
td
d
td
tmd
ρ
∂
ρ∂
ρ
∂
ρ∂
ρ
( )∫∫∫=
∫∫∫∫∫ ∫∫∫
+
+===
)(
1
)()( )(
)(
0
tv
k
k
GAUSS
tS
kk
tv tv
REYNOLDS
F
FF F
vdu
xt
sduvd
t
dv
td
d
td
tmd
ρ
∂
∂
∂
ρ∂
ρ
∂
ρ∂
ρ
The Control Volume mass rate is zero as long as vF(t) is attached to the fluid and
therefore contains the same amount of mass.
0),,,(
)(
=∫∫∫
tvF
vdtzyx
td
d
ρ is true in any Coordinate System (O) and so is:
( ) ( ) ( ) ( )( ) 0,,,,,,
,,,
,,,
)(
,,
)(
=
⋅∇+= ∫∫∫∫∫∫
tv
OO
tv FF
vdtzyxutzyx
t
tzyx
vdtzyx
td
d
ρ
∂
ρ∂
ρ
SOLO
50. 50
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.1) CONSERVATION OF MASS (CONTINUE - 2)
VECTOR NOTATION CARTESIAN TENSOR NOTATION
For any Control Volume v (t) (not necessarily attached to the fluid)
The following is true for any Coordinate System (for points that are not sources or
sinks – mathematically equivalent to analytic) ( )OO u
t
,,,
ρ
∂
ρ∂
⋅∇
( ) OOOOOO uu
t
u
t
,,,,,,0
⋅∇+∇⋅+=⋅∇+= ρρ
∂
ρ∂
ρ
∂
ρ∂
( )
k
k
k
kO
k
x
u
x
u
t
u
xt ∂
∂
ρ
∂
ρ∂
∂
ρ∂
ρ
∂
∂
∂
ρ∂
++=+= ,0
( )
( ) 0
)(
,,
4
).(
,
).()(
≠=
⋅∇+
⋅+
∫∫∫=
∫∫∫∫∫=∫∫∫
mvdV
t
sdVvd
t
vd
td
d
tv
OSO
GAUSS
tS
OS
tv
LEIBNITZ
tv
ρ
∂
ρ∂
ρ
∂
ρ∂
ρ
( ) 0
)(
,
4
).(
,
).()(
≠=
+
+
∫∫∫=
∫∫∫∫∫=∫∫∫
mvdV
xt
sdVvd
t
vd
td
d
tv
kOS
k
GAUSS
tS
kkOS
tv
LEIBNITZ
tv
ρ
∂
∂
∂
ρ∂
ρ
∂
ρ∂
ρ
The integral above is not zero because the mass in v (t) is not constant.
SOLO
51. 51
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.1) CONSERVATION OF MASS (CONTINUE - 3)
Material Derivative of vdmd ρ=
Let use EULER’s 1755 expression ( ) ( )
( ) ( )vd
tD
D
vdtd
tvd
tv
u F
F
tv
OO
F
11
lim
0
,, =
=⋅∇
→
and the (C.M.):
to develop the following:
( ) 0,,
=⋅∇+ OO
u
t
ρ
∂
ρ∂
( ) ( )
( ) 0,,,,,,
,,,,
=
⋅∇+
∂
∂
=
⋅∇+∇⋅+
∂
∂
=
⋅∇+
∇⋅+
∂
∂
=+==
vdu
t
vduu
t
uvdvdu
t
vd
tD
D
vd
tD
D
vd
tD
D
tD
mD
OOOOOO
OOOO
ρ
ρ
ρρ
ρ
ρρ
ρ
ρ
ρ
ρ
SOLO
52. 52
FLUID DYNAMICS
∑+=
openings
i
iopenW SCSCSC ....
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.1) CONSERVATION OF MASS (CONTINUE – 4)
SOLO
Control Volume with fixed shape C.V. and boundary C.S. in O Coordinates( ) 0,
=OS
V
There are no sources or sinks in the volume C.V. The change in the mass of the
system is due only to the flow through the surface openings C.Sopen i (i=1,2,…). The
surface C.S. can be divided in:
• C.Sw the impermeable wall through which the fluid can not escape .
=−= 0
0
,,,
OSOs
VuV
• C.Sopen i the openings (i=1,2,…) through which the fluid enters or exits .( )0>m ( )0<m
∑∑ ∫∫∫∫∫∫∫∫∫ =⋅−⋅−=⋅−==
openings
i
i
openings
i
m
SC
O
SC
O
SC
O
VC
msdusdusduvd
td
d
td
md
i
iopenw
.
,
.
0
,
..
,
..
ρρρρ
Therefore
where is the flow rate entering through the opening Sopen i.∫∫ ⋅−=
iopenSC
Oi
sdum
.
,
ρ
Return to Table of Content
53. 53
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.2) CONSERVATION OF LINEAR MOMENTUM (C.L.M.)
-Fluid density at he point and time t( )tr,
ρ
r ( )3
/ mKg
-Fluid inertial velocity at the point
and time t
( )tru I
,,
r
( )sec/m
-Surface Stress ( )2
/ mNT
-Pressure (force per unit surface) of the surrounding
on the control surface ( )2
/ mN
p
-Stress tensor (force per unit surface) of the surrounding
on the control surface ( )2
/ mN
σ~
-Body forces acceleration
-(gravitation, electromagnetic,..)
G
( )2
sec/m
nnpnT ˆ~ˆˆ~ ⋅+−=⋅= τσ
Consider a volume vF(t) attached to the fluid, bounded by the closed surface SF(t).
SOLO
-unit vector normal to the surface S(t) and pointing outside the volume v (t)nˆ
vF (t)
m
SF (t)
O
x
y
z
r u,O
np ˆ−
nˆ~⋅τ
nˆ~⋅σ
dSnˆ
-Shear stress tensor (force per unit surface) of the surrounding on the control
surface ( )2
/ mN
τ~
54. 54
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.2) CONSERVATION OF LINEAR MOMENTUM (CONTINUE - 1)
Derivation From Integral Form
The LINEAR MOMENTUM of the Constant Mass in vF(t) is given by:
∫∫∫=
)(
,
tv
I
F
vduP
ρ
The External Forces acting on the mass are Body and Surface Forces:
( )
ForcesSurface
tS
ForcesBody
tv
external
FF
sdTvdGF ∫∫∫∫∫∑ +=
)(
ρ
According to NEWTON’s Second Law, for a constant mass in vF(t), we have:
I
external
td
Pd
F
=∑
SOLO
55. 55
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.2) CONSERVATION OF LINEAR MOMENTUM (CONTINUE - 2)
VECTOR NOTATION CARTESIAN TENSOR NOTATION
( )
I
IMomentumLinear
tv
I
REYNOLDS
tv
I
I
ForcesSurface
tS
ForcesBody
tv
external
P
td
d
vdu
td
d
vd
tD
uD
sdvdGF
FF
FF
===
⋅+=
∫∫∫∫∫∫
∫∫∫∫∫∑
)(
,
3
)(
,
)()(
~
ρρ
σρ
i
tv
i
REYNOLDS
tv
i
tS
kik
tv
iiex
P
td
d
vdu
dt
d
vd
tD
uD
dsvdGF
FF
FF
===
+=
∫∫∫∫∫∫
∫∫∫∫∫∑
)(
3
)(
)()(
_
ρρ
σρ
C.L.M.-1
T ds n ds ds
ds n ds
= ⋅ ⋅
=
=~ ~σ σ T ds n ds dsi ik k
ds n ds
ik k
k k
=
=
=σ σ
C.L.M.-2
( )∫∫∫
∫∫∫∫∫∫∫∫
⋅∇+=
⋅+=
)(
,
)()()(
,
~
~
tv
I
tStvtv
I
I
F
FFF
vdG
sdvdGvd
tD
uD
σρ
σρρ
∫∫∫
∫∫∫∫∫∫∫∫
+=
+=
)(
)()()(
tv i
ik
i
tS
kik
tv
i
tv
i
F
FFF
vd
x
G
sdvdGvd
tD
uD
∂
σ∂
ρ
σρρ
SOLO
Derivation From Integral Form (Continue)
56. 56
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.2) CONSERVATION OF LINEAR MOMENTUM (CONTINUE - 3)
VECTOR NOTATION CARTESIAN TENSOR NOTATION
C.L.M.-2
Since this is true for all volumes vF (t) attached to the fluid we can drop the volume integral.
[ ] [ ] [ ]τσ
τρσρ
∂
∂
ρ
∂
∂
ρρ
~~
~~
2
1
,,,
,
2
,
,
.).(
+−=
⋅∇+∇−=⋅∇+=
×∇×−
∇+=
∇⋅+=
Ip
pGG
uuu
t
u
uu
t
u
tD
uD
III
II
I
I
I
DM
I
ikikik
i
ik
i
i
i
ik
i
k
i
k
i
j
jjj
i
i
k
i
k
i
DM
i
p
xx
p
G
x
G
x
u
u
x
u
uuu
xt
u
x
u
u
t
u
tD
uD
τδσ
∂
τ∂
∂
∂
ρ
∂
σ∂
ρ
∂
∂
∂
∂
∂
∂
∂
∂
ρ
∂
∂
∂
∂
ρρ
+−=
+−=+=
⋅−⋅−
+=
⋅+=
2
1
.).(
SOLO
Derivation From Integral Form (Continue)
( )∫∫∫
∫∫∫∫∫∫∫∫
⋅∇+=
⋅+=
)(
,
)()()(
,
~
~
tv
I
tStvtv
I
I
F
FFF
vdG
sdvdGvd
tD
uD
σρ
σρρ
∫∫∫
∫∫∫∫∫∫∫∫
+=
+=
)(
)()()(
tv i
ik
i
tS
kik
tv
i
tv
i
F
FFF
vd
x
G
sdvdGvd
tD
uD
∂
σ∂
ρ
σρρ
57. 57
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.2) CONSERVATION OF LINEAR MOMENTUM (CONTINUE - 4)
Derivation From a Cartesian Differential Volume
VECTOR NOTATION CARTESIAN TENSOR NOTATION
σ
∂ σ
∂
xx
xx
x
dx+
1
2
σ
∂ σ
∂
xx
xx
x
dx−
1
2
τ
∂ τ
∂
yx
yx
y
dy+
1
2
τ
∂ τ
∂
yz
yz
y
dy−
1
2
τ
∂τ
∂
zx
zx
z
dz+
1
2
τ
∂τ
∂
zx
zx
z
dz−
1
2
τ
∂ τ
∂
xy
xy
x
dx+
1
2
τ
∂ τ
∂
xy
xy
x
dx−
1
2
σ
∂ σ
∂
yy
yy
y
dy+
1
2
σ
∂ σ
∂
yy
yy
y
dy−
1
2
τ
∂τ
∂
zy
zy
z
dz+
1
2
τ
∂τ
∂
zy
zy
z
dz−
1
2
τ
∂ τ
∂
xz
xz
x
dx−
1
2
τ
∂ τ
∂
yz
yz
y
dy+
1
2
τ
∂ τ
∂
yx
yx
y
dy−
1
2
σ
∂ σ
∂
zz
zz
z
dz+
1
2
σ
∂ σ
∂
zz
zz
z
dz−
1
2
z
y
x
dy
dx
dz
O
τ
∂ τ
∂
xz
xz
x
dx+
1
2
∂σ
∂
∂τ
∂
∂τ
∂
ρ ρ
∂τ
∂
∂σ
∂
∂τ
∂
ρ ρ
∂τ
∂
∂τ
∂
∂σ
∂
ρ ρ
xx yx zx
xB x
xy yy zy
yB y
xz yz zz
zB z
x y z
G a
x y z
G a
x y z
G a
+ + + =
+ + + =
+ + + =
CAUCHY’s First Law of Motion
I
tD
uD
a
aG
=
=+⋅∇ ρρσ~
tD
uD
a
aG
x
i
i
ii
i
ij
=
=+ ρρ
∂
σ∂
SOLO
AUGUSTIN LOUIS
CAUCHY
)1789-1857(
58. 58
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.2) CONSERVATION OF LINEAR MOMENTUM (CONTINUE-5)
Derivation For Any Control Volume v (t)
(the velocity of an element of surface is )d s
IS
V ,
V(t)
b
ds
V*(t)
I
T d s= ⋅~σ
G
m
u Use REYNOLDS’ Transport Theorem (REYNOLDS 2)
with and O = I, and then the Conservation
of Linear Momentum (C.L.M.)
I
u,
=η
VECTOR NOTATION CARTESIAN TENSOR NOTATION
( )[ ]
( ) ( )
( )
∑∫∫∫∫∫
∫∫∫∫∫∫
∫∫∫∫∫
=⋅+=
⋅∇+==
⋅−+
iexternal
tStv
tv
I
MLC
tv
I
REYNOLDS
tS
ISII
I
tv
I
FsdvdG
vdGvd
tD
uD
sdVuuvdu
td
d
FF
FF
FF
)()(
)(
,
...
)(
2
)(
,,,
)(
,
~
~
σρ
σρρ
ρρ ( )
( ) ( )
∑∫∫∫∫∫
∫∫∫∫∫∫
∫∫∫∫∫
=+=
+==
−+
iexternal
tS
kik
tv
i
tv k
ik
i
MLC
tv
i
REYNOLDS
tS
kkISki
tv
i
FsdvdG
vd
x
Gvd
tD
uD
sdVuuvdu
td
d
)()(
)(
...
)(
2
)(
,
)(
σρ
∂
σ∂
ρρ
ρρ
SOLO
Return to Table of Content
59. 59
( ) ( ) PdRRvdVRRHd OOO
×−=×−= ρ,
2. BASIC LAWS IN FLUID DYNAMICS
(2.3) CONSERVATION OF MOMENT-OF-MOMENTUM (C.M.M.)
SOLO
The Absolute Angular Momentum, of the differential mass
and Inertial Velocity ,relative to a reference point O is defined as
vdmd ρ=
V
The Absolute Angular Momentum of the mass
enclosed by C.V. is defined as
( ) ( )∫∫∫∫∫∫ ×−=×−=
....
,
VC
O
VC
OOCV
PdRRvdVRRH
ρ
Let differentiate the Absolute Angular Momentum
and use Reynolds’ Transport Theorem
( ) ( ) ( ) ( )∫∫∫∫∫∫∫∫ ⋅−×−+
×−
=×−=
..
,
....
,
SC
md
SO
VC
I
O
REYNOLDS
I
VC
O
I
OCV
sdVVRRvd
tD
VRRD
vdVRR
td
d
td
Hd
ρρρ
We have ( ) ( )
( ) ( ) ( ) VV
tD
VD
RRVVV
tD
VD
RR
V
tD
RD
tD
RD
tD
VD
RR
tD
VRRD
O
I
OO
I
O
I
O
II
O
I
O
×−×−=×−+×−=
×
−+×−=
×−
FLUID DYNAMICS
60. 60
( ) ( ) ( ) int,
: fdRRfdRRvd
tD
VD
RRMd OextO
I
OO
×−+×−=×−= ρ
( ) ( ) ( ) ( )∫∫∫∫∫∫∫∫∫∫∫ ⋅−×−+×−×−=×−=
..
,
......
,
SC
md
SO
P
VC
O
VC
I
O
REYNOLDS
I
VC
O
I
OCV
sdVVRRvdVVvd
tD
VD
RRvdVRR
td
d
td
Hd
CV
ρρρρ
2. BASIC LAWS IN FLUID DYNAMICS
(2.3) CONSERVATION OF MOMENT-OF-MOMENTUM (C.M.M.)
SOLO
The Moment, of the differential mass dm = ρdv, relative to a reference
point O is defined as
Therefore
Let integrate this equation over the control volume C.V.
( ) ( ) ( )
0
..
int
....
, ∫∫∫∫∫∫∫∫∫∑ ×−+×−=×−=
VC
O
VC
extO
VC
I
OOCV
fdRRfdRRvd
tD
VD
RRM ρ
Using the differential of Angular Momentum equation we obtain
( ) ( ) ( )∫∫∫∫∫∑∫∫∫ ⋅−×−+×−=×−=
..
,
..
,
..
,
SC
md
SO
P
VC
OOCV
I
VC
O
I
OCV
sdVVRRvdVVMvdVRR
td
d
td
Hd
CV
ρρρ
( ) ( ) ( ) ( ) ( ) ∑∑∫∫∫∫∫∫∫∫∑ +×−++−×−+×−=×−=
=⋅
k
k
j
jOj
SC
sdTsd
O
VC
O
VC
extOOtCV MFRRsdtfnpRRvdgRRfdRRM
......
, 11
σ
ρ
Also
( )∑ ×−
j
jOj FRR
- Moment, relative to O, of discrete forces exerting by the surrounding at point jR
- Discrete Moments exerting by the surrounding.∑
k
k
M
FLUID DYNAMICS
61. 61
( ) ( ) ( )
∑∑∫∫∫∫∫∫∫∫ +×+×+×=×+⋅−×−×
k
k
j
jO
tv
O
tv
extO
P
VC
O
SC
md
SO
I
VC
O MFrfdrfdrvdVVsdVVrvdVr
td
d
CV
,
0
int,,
....
,,
..
, ρρρ
2. BASIC LAWS IN FLUID DYNAMICS
(2.3) CONSERVATION OF MOMENT-OF-MOMENTUM (C.M.M.)
SOLO
Let find the equation of moment around the
turbomachine axis.
We shall use polar coordinates , where z is
the turbomachine axis.
zr ,,θ
zzrrrO
ˆˆ, +=
zVVrVV zr
ˆˆˆ ++= θθ
zFFrFF zr
ˆˆˆ ++= θθ
( ) zVrVrVzrVz
VVV
zr
zr
Vr zrz
zr
O
ˆˆ0
ˆˆˆ
, θ
θ
θ
+−+−==×
( ) ( )
∑∑∫∫∫∫ ++=×+⋅−−
k
kz
j
j
tv
extCVO
SC
S
VC
MFrdfrPVsdVVrvdVr
td
d
θθθθ ρρ
0
..
,
..
The moment of momentum equation around the turbomachine z axis.
Example
FLUID DYNAMICS
62. 62
2. BASIC LAWS IN FLUID DYNAMICS
(2.3) CONSERVATION OF MOMENT-OF-MOMENTUM (C.M.M.)
SOLO
( )
( ) ( ) ( ) ( )
( )
systemoutsidefromexertedTorque
M
l
lz
j
j
tv
ext
AVVrAVVr
SC
S
statesteady
VC
zSnSn
MFrdfrsdVVrvdVr
td
d
∑∑∫∫∫∫ ++=⋅−−
+−−→
θθ
ρρ
θθ
θθ
ρρ
22,21111,122
..
,
0
..
We obtain
( ) ( )[ ] zflow
MQVrVr =− 111122
ρθθ
or
( ) ( ) ( ) ( ) ( ) ( )[ ] ( ) zSnSnSn
MAVVrVrAVVrAVVr =−=− 11,1112211,11122,222
ρρρ θθθθ
Euler Turbine Equation
ρ1 - mean fluid density one inlet (1) of area A1.
where
ρ2 - mean fluid density one outlet (2) of area A2.
(Vθ )1, r1 - mean fluid tangential velocity and radius one inlet (1) of area A1.
(Vθ )2, r2 - mean fluid tangential velocity and radius one outlet (2) of area A2.
(V,Sn )1 - mean fluid normal velocity (relative to A1) one inlet (1) of area A1.
(V,Sn )2 - mean fluid normal velocity (relative to A2) one outlet (2) of area A2.
- mean flow rate one outlet (1) of area A1.( ) 11,1 : AVQ Snflow =
FLUID DYNAMICS
Return to Table of Content
63. 63
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.4) CONSERVATION OF ENERGY (C.E.)
– THE FIRST LAW OF THERMODYNAMICS (DIFFERENTIAL FORM)
-Fluid mean velocity [m/sec[( )
u r t,
-Body Forces Acceleration
-(gravitation, electromagnetic,..)
G
-Surface Stress [N/m2
[T
nnpnT ˆ~ˆˆ~ ⋅+−=⋅= τσ
m
V(t)
G
q
T n= ⋅~σ
d E
d t
∂
∂
Q
t
uu
d s n ds=
-Internal Energy of Fluid molecules
(vibration, rotation, translation per
mass [W/kg[
e
- Rate of Heat transferred to the Control Volume
(chemical, external sources of heat) [W/m3
[
∂
∂
Q
t
- Rate of Work change done on fluid by the surrounding (rotating shaft, others)
positive for a compressor, negative for a turbine) [W[td
Ed
SOLO
Consider a volume vF(t) attached to the fluid, bounded by the closed surface SF(t).
-Rate of Conduction and Radiation of Heat from the Control Surface
(per unit surface) [W/m3
[
q
64. 64
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.4) CONSERVATION OF ENERGY (C.E.)
– THE FIRST LAW OF THERMODYNAMICS (CONTINUE - 1)
- The Internal Energy of the molecules of the fluid plus the
Kinetic Energy of the mass moving relative to an
Inertial System (I)
The FIRST LAW OF THERMODYNAMICS
CHANGE OF INTERNAL ENERGY + KINETIC ENERGY =
CHANGE DUE TO HEAT + WORK + ENERGY SUPPLIED BY SUROUNDING
SOLO
The energy of the constant mass m in the volume vF(t) attached to the fluid,
bounded by the closed surface SF(t) is
This energy will change due to
- The Work done by the surrounding
- Absorption of Heat
- Other forms of energy supplied to the mass
(electromagnetic, chemical,…)
65. 65
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.4) CONSERVATION OF ENERGY (C.E.)
– THE FIRST LAW OF THERMODYNAMICS (CONTINUE - 2)
VECTOR NOTATION CARTESIAN TENSOR NOTATION
C.E.-1
systementering
td
Qd
tSv
systemontnmenenvirobydone
td
Wd
shaft
tSv
v
REYNOLDS
KineticInternal
tv
FF
FF
FF
sdqvd
t
Q
td
Wd
ForcesSurface
sdTu
ForcesBody
vdGu
vdue
tD
D
vdue
td
d
∫∫∫∫∫
∫∫∫∫∫
∫∫∫∫∫∫
⋅−+
+⋅+⋅=
+=
+
+
)(
)(
2
)3(
)(
2
2
1
2
1
∂
∂
ρ
ρρ
systementering
td
Qd
tS
kk
tv
systemontnemnoenvirbydone
td
Wd
shaft
tS
kk
tv
kk
tv
REYNOLDS
KineticInternal
tv
FF
FF
FF
dsqvd
t
Q
td
Wd
ForcesSurface
sdTu
ForcesBody
vdGu
vdue
tD
D
vdue
td
d
∫∫∫∫∫
∫∫∫∫∫
∫∫∫∫∫∫
−+
++=
+=
+
+
)()(
)()(
)(
2
)3(
)(
2
2
1
2
1
∂
∂
ρ
ρρ
SOLO
66. 66
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.4) CONSERVATION OF ENERGY (C.E.)
– THE FIRST LAW OF THERMODYNAMICS (CONTINUE - 3)
VECTOR NOTATION CARTESIAN TENSOR NOTATIONC.E.-2
( ) ( )
∫∫∫∫∫∫
∫∫∫∫∫∫∫∫∫
∫∫∫∫∫
∫∫∫∫∫∫∫
∫∫∫
⋅∇−+
⋅⋅∇+⋅∇−⋅=
⋅−+
⋅⋅+⋅−⋅=
+
+
)()(
)()()(
)1(
)()(
)()()(
)(
2
~
~
2
1
tvtv
tvtvtv
GAUSS
td
Qd
tStv
td
Wd
tStStv
tv
FF
FFF
FF
FFF
F
vdqvd
t
Q
vduvdupvdGu
sdqvd
t
Q
sdusdupvdGu
KineticInternal
vdue
tD
D
∂
∂
τρ
∂
∂
τρ
ρ
( ) ( )
∫∫∫∫∫∫
∫∫∫∫∫∫∫∫∫=
∫∫∫∫∫
∫∫∫∫∫∫∫
∫∫∫
−+
+−
−+
+−=
+
+
)()(
)()()(
)1(
)()(
)()()(
)(
2
2
1
tV s
s
tV
tV
k
k
iki
tV
k
k
k
tV
kk
GAUSS
td
Qd
tS
kk
tV
td
Wd
tS
kiki
tS
kk
tV
kk
KineticInternal
tV
vd
x
q
vd
t
Q
ds
x
u
ds
x
up
vdGu
dsqvd
t
Q
dsudsupvdGu
vdue
tD
D
∂
∂
∂
∂
∂
τ∂
∂
∂
ρ
∂
∂
τρ
ρ
T n pn n ds n ds= ⋅ = − + ⋅ =~ ~ &σ τ0=
td
Wd shaft
assume and use
SOLO
67. 67
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.4) CONSERVATION OF ENERGY (C.E.)
– THE FIRST LAW OF THERMODYNAMICS (CONTINUE-4)
VECTOR NOTATION CARTESIAN TENSOR NOTATIONC.E.-3
Since the last equation is valid for each vF(t) we can drop the integral and obtain:
( ) ( )
q
t
Q
uGuupue
tD
D
⋅∇−+
⋅+⋅⋅∇+⋅−∇=
+
∂
∂
ρτρ ~
2
1 2 ( ) ( )
k
k
kk
k
iik
k
k
x
q
t
Q
uG
x
u
x
up
ue
tD
D
∂
∂
∂
∂
ρ
∂
τ∂
∂
∂
ρ
−+
++−=
+ 2
2
1
Multiply (C.L.M.-2) by
u
τρρ ~⋅∇⋅+∇⋅−⋅=⋅ upuuG
tD
uD
u
( )
k
ik
i
k
kkk
i
i
x
u
x
p
uuGu
tD
D
tD
uD
u
∂
τ∂
∂
∂
ρρρ +−== 2
Subtract this equation from (C.E.-3)
C.E.-4
( )[ ]ρ τ τ
∂
∂
D e
D t
p u u u
Q
t
q
= − ∇⋅ + ∇⋅ ⋅ − ⋅∇⋅
+ −∇⋅
~ ~
Φ
ρ
∂
∂
τ
∂
∂
∂
∂
∂
∂
D e
D t
p
u
x
u
u
x
Q
t
q
x
k
k
ik
i
k
k
k
=− +
+ −
Φ
( )Φ ≡ ∇⋅ ⋅ − ⋅∇ ⋅ >~ ~τ τ
u u 0
Φ ≡ >τ
∂
∂
ik
i
k
u
x
0
(Proof of inequality given later)
SOLO
68. 68
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.4) CONSERVATION OF ENERGY (C.E.)
– THE FIRST LAW OF THERMODYNAMICS (CONTINUE - 5)
VECTOR NOTATION CARTESIAN TENSOR NOTATION
Enthalpy
Use this result and (C.E.-4)
C.E.-5
ρ
p
eh +=:
( )
tD
pD
up
tD
hD
u
p
tD
pD
tD
hD
tD
Dp
tD
pD
tD
hD
tD
pD
tD
hD
tD
eD
−⋅∇−=⋅∇−+−=
+−=
−=
ρρ
ρ
ρ
ρ
ρ
ρ
ρ
ρ
ρ
ρ
ρρρ 2
tD
pD
x
u
p
tD
hD
x
up
tD
pD
tD
hD
tD
pDp
tD
hD
tD
pD
tD
pD
tD
hD
tD
eD
k
k
k
k
−−=
−+−=
+−=
−=
∂
∂
ρ
∂
∂
ρ
ρ
ρ
ρ
ρ
ρ
ρ
ρ
ρ
ρρρ 2
Φ++⋅∇−=
t
Q
q
tD
pD
tD
hD
∂
∂
ρ
Φ++−=
t
Q
x
q
tD
pD
tD
hD
k
k
∂
∂
∂
∂
ρ
SOLO
( )Φ ≡ ∇⋅ ⋅ − ⋅∇ ⋅ >~ ~τ τ
u u 0
Φ ≡ >τ
∂
∂
ik
i
k
u
x
0
69. 69
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.4) CONSERVATION OF ENERGY (C.E.)
– THE FIRST LAW OF THERMODYNAMICS (CONTINUE - 6)
VECTOR NOTATION CARTESIAN TENSOR NOTATION
Total Enthalpy
Use this result and (C.E.-3)
C.E.-6
22
2
1
2
1
: u
p
euhH ++=+=
ρ
( )
t
p
up
tD
HD
tD
pD
up
tD
HD
p
tD
D
tD
HD
ue
tD
D
∂
∂
ρρ
ρ
ρρρ
−⋅∇−=−⋅∇−=
−=
+
2
2
1
( )
t
p
up
xtD
HD
tD
pD
x
u
p
tD
HD
p
tD
D
tD
HD
ue
tD
D
kk
k
∂
∂
∂
∂
ρ
∂
∂
ρ
ρ
ρρρ
−−=−−=
−=
+
2
2
1
( ) q
t
Q
uGu
t
p
tD
HD
⋅∇−+⋅+⋅⋅∇+=
∂
∂
ρτ
∂
∂
ρ ~ ( )
k
k
kk
k
iik
x
q
t
Q
uG
x
u
t
p
tD
HD
∂
∂
∂
∂
ρ
∂
τ∂
∂
∂
ρ −+++=
SOLO
Return to Table of Content
70. 70
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
SOLO
THERMODYNAMIC PROCESSES
1. ADIABATIC PROCESSES
2. REVERSIBLE PROCESSES
3. ISENTROPIC PROCESSES
No Heat is added or taken away from the System
No dissipative phenomena (viscosity, thermal, conductivity, mass diffusion,
friction, etc)
Both adiabatic and reversible
(2.5) THE SECOND LAW OF THERMODYNAMICS AND ENTROPY PRODUCTION
71. 71
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.5) THE SECOND LAW OF THERMODYNAMICS AND ENTROPY PRODUCTION
2nd
LAW OF THERMODYNAMICS
Using GAUSS’ THEOREM
0
)()(
≥+ ∫∫∫∫∫
tStv FF
Ad
T
q
vds
td
d
ρ
00
)(
)1(
)()(
≥
⋅∇+⇒≥+ ∫∫∫∫∫∫∫∫
tv
GAUSS
tStv FFF
vd
T
q
tD
sD
Ad
T
q
vd
tD
sD
ρρ
- Change in Entropy per unit volumed s
- Local TemperatureT [ ]K
- Fluid Densityρ [ ]3
/ mKg
d e q w T ds pdv= + = −δ δ d s
d e
T
p
T
dv= +
SOLO
For a Reversible Process
- Rate of Conduction and Radiation of Heat from the System
per unit surface
q
[ ]2
/ mW
72. 72
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.5) THE SECOND LAW OF THERMODYNAMICS (CONTINUE - 1)
d e q w T ds pdv= + = −δ δ d s
d e
T
p
T
dv= +
u
T
p
tD
eD
T
u
T
p
tD
eD
T
tD
D
T
p
tD
eD
TtD
D
T
p
tD
eD
TtD
vD
T
p
tD
eD
TtD
sD
u
tD
D
MC
v
⋅∇+=
⋅∇+=
−+=
+=+=
⋅∇−=
=
ρ
ρ
ρ
ρρ
ρ
ρ
ρρ
ρ
ρρρρ
ρ
ρ
ρ
ρ
2
.).(
2
1
1
11
The Energy Equation (C.E.-4) is
( )
k
i
ik
x
u
oruu
t
Q
qup
tD
eD
∂
∂
τττ
∂
∂
ρ =Φ⋅∇⋅−⋅⋅∇=ΦΦ++⋅∇−⋅∇−= ~~
Tt
Q
TT
q
up
tD
eD
TtD
sD Φ
++
⋅∇
−=
⋅∇+=
∂
∂
ρ
11
or
Φ++⋅−∇=
t
Q
q
tD
sD
T
∂
∂
ρ
SOLO
73. 73
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.5) THE SECOND LAW OF THERMODYNAMICS (CONTINUE - 2)
Define
ρ
∂
∂
T
D s
Dt
q
Q
t
= −∇ ⋅ + +
Φ
Θ ≡ + ∇ ⋅
≥ρ
Ds
Dt
q
T
0 Entropy Production Rate per unit volume
Therefore
( )
Θ
Φ
Θ= −
∇ ⋅
+ + + ∇ ⋅
≥∫∫∫
q
T T
Q
t T
q
T
dv
V t
1
0
∂
∂
&
SOLO
or
0
1
≥Φ++⋅∇⋅−=Θ
nDissipatio
System
toadded
Heat
System
from
Radiation
Heat
t
Q
Tq
T
T
∂
∂
74. 74
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.5) THE SECOND LAW OF THERMODYNAMICS (CONTINUE - 3)
q q q
q conduction rate per unit surface
q radiation rate per unit surfacec r
c
r
= +
q K T K FOURIER s Conduction Lawc = − ∇ > 0 '
( )−
∇ ⋅
+ ∇ ⋅
= −
∇ ⋅
+ ∇ ⋅ + ⋅∇
= ⋅∇
= − ∇ + ⋅∇
= − ∇ ⋅ − ∇
+ ⋅∇
=
∇
+ ⋅∇
q
T
q
T
q
T T
q q
T
q
T
K T q
T
K T
T
T q
T
K
T
T
q
T
r
r r
1 1 1 1
1 1 1
2
2
Θ
Φ
Φ=
∇
+ + + ⋅∇
>
>
>
K
T
T T T
Q
t
q
T
K
T
r
2
1 1
0
0
0
∂
∂
Θ
Φ
≡ + ∇⋅
=
∇
+ + + ⋅∇
≥ρ
∂
∂
D s
D t
q
T
K
T
T T T
Q
t
q
Tr
2
1 1
0
SOLO
JEAN FOURIER
1768-1830
75. 75
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.5) THE SECOND LAW OF THERMODYNAMICS (CONTINUE - 4)
SOLO
Gibbs Function
Helmholtz Function
sThG ⋅−=:
sTeH ⋅−=:
Josiah Willard Gibbs
(1839-1903)
Hermann Ludwig Ferdinand
von Helmholtz
(1821 – 1894)
Using the Relations
vdpsdTed ⋅−⋅=
( ) pdvsdTvpdedhd ⋅+⋅=⋅+=vpe
p
eh ⋅+=+=
ρ
:
pdvTdssdTTdshdGd ⋅+⋅−=⋅−⋅−=
vdpTdsTdssdTedHd ⋅−⋅−=⋅−⋅−=
dv
T
p
T
ed
sd +=
76. 76
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.5) THE SECOND LAW OF THERMODYNAMICS (CONTINUE - 5)
SOLO
Maxwell’s Relations
vdpsdTed ⋅−⋅=
pdvsdThd ⋅+⋅=
pdvTdsGd ⋅+⋅−=
vdpTdsHd ⋅−⋅−=
Ts
pv
v
F
p
v
e
s
h
T
s
e
∂
∂
=−=
∂
∂
∂
∂
==
∂
∂
vp
Ts
T
F
s
T
G
p
G
v
p
h
∂
∂
=−=
∂
∂
∂
∂
==
∂
∂
ps
vs
s
v
p
T
s
p
v
T
∂
∂
=
∂
∂
∂
∂
−=
∂
∂
vT
pT
T
p
v
s
T
v
p
s
∂
∂
=
∂
∂
∂
∂
−=
∂
∂
James Clerk Maxwell
(1831-1879)
Return to Table of Content
77. 77
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.6) CONSTITUTIVE RELATIONS FOR GASES
(2.6.1) NEWTONIAN FLUID DEFINITION – NAVIER–STOKES EQUATIONS
[ ] τσ ~~ +−= Ip
Stress
NEWTONIAN FLUID:
The Shear Stress on
A Surface Parallel
To the Flow =
Distance Rate of
Change of Velocity
SOLO
CARTESIAN TENSOR NOTATION
ikikik p τδσ +−=
VECTOR NOTATION
- Stress tensor (force per unit surface) of the surrounding
on the control surface ( )2
/ mN
σ~
-Shear stress tensor (force per unit surface) of the surrounding on the control
surface ( )2
/ mN
τ~
78. 78
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.6) CONSTITUTIVE RELATIONS
(2.6.1) NEWTONIAN FLUID DEFINITION – NAVIER–STOKES EQUATIONS
M. NAVIER 1822
INCOMPRESSIBLE FLUIDS
(MOLECULAR MODEL)
G.G. STOKES 1845
COMPRESSIBLE FLUIDS
(MACROSCOPIC MODEL)
VECTOR NOTATION CARTESIAN TENSOR NOTATION
[ ] [ ] ( )[ ] [ ]IuuuIpIp
T
∇+∇+∇+−=+−= λµτσ ~~
ik
k
k
i
k
k
i
ikikikik
x
u
x
u
x
u
pp δ
∂
∂
λ
∂
∂
∂
∂
µδτδσ +
++−=+−=
( )[ ] [ ]( ) ( ) ( ) µλλµλµτ
3
2
32~0 −=⇒∇+∇=∇+∇+∇== utrutrIutruutrtr
T
( ) µλ
∂
∂
λµδ
∂
∂
λ
∂
∂
µτ
3
2
0322 −=⇒=+=+=
i
i
ik
k
k
i
i
ii
x
u
x
u
x
u
SOLO
STOKES ASSUMPTION µλ
3
2
−=0~ =τtrace
μ, λ - Lamé parameters from Elasticity
79. 79
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.6) CONSTITUTIVE RELATIONS
(2.6.1) NAVIER–STOKES EQUATIONS (CONTINUE)
(2.6.1.2) VECTORIAL DERIVATION
I
x
y
z
T n= ⋅~σ
d s n ds=
r
dru
u +du( )unrdtd
t
u
urdtd
t
u
ud
∇⋅+=∇⋅+= 1
∂
∂
∂
∂
( ) ( ) ( ) rdnurdnuuntd
t
u
ud
RotationnTranslatio
1
2
1
1
2
1
1 ××∇+
××∇−∇⋅+=
∂
∂
OR
DEFINITION OF NEWTONIAN FLUID, NAVIER-STOKES EQUATION
( ) ( ) nnunuunnpT
nTranslatio
1~11
2
1
121 ⋅=⋅∇+
××∇−∇⋅+−≡ σλµ
CONSERVATION OF LINEAR MOMENTUM EQUATIONS
SOLO
80. 80
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.6) CONSTITUTIVE RELATIONS
(2.6.1) NAVIER–STOKES EQUATIONS (CONTINUE)
(2.6.1.2)VECTORIAL DERIVATION (CONTINUE) I
x
y
z
T n= ⋅~σ
d s n ds=
r
dru
u + du
CONSERVATION OF LINEAR MOMENTUM
EQUATIONS
( ) ( )
( ) ( ) ( )
( )
( )
( )
( )
( )
( )
( )
∫∫∫
∫∫∫∫∫∫∫∫∫∫∫
∫∫∫∫∫∫∫∫∫∫∫∫∫∫∫
⋅∇∇+×∇×∇+∇⋅∇+∇−=
=⋅∇+×∇×+∇⋅+−=
⋅∇+
××∇−∇⋅+⋅−=+=
)(
)()()()()(
)()()()()()(
251
2
2
2
11
2
1
121
tV
GAUSS
tStStStStV
tStStVtStVtV
vd
GAUSS
u
GAUSS
u
GAUSS
u
GAUSS
pG
usdusdusdsdpvdG
sdnunuunsdnpvdGdsTvdGvd
tD
uD
λµµρ
λµµρ
λµρρρ
BUT
( ) ( ) ( )∇× ∇× ≡ ∇ ∇⋅ − ∇⋅ ∇2 2 2µ µ µ
u u u
( ) ( ) ( ) ( )∇⋅ ∇ + ∇× ∇× = ∇ ∇⋅ − ∇× ∇×2 2µ µ µ µ
u u u u
THEN
SOLO
81. 81
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
I
x
y
z
T n= ⋅~σ
d s n ds=
r
dru
u + du
THEREFORE
( ) ( ) ( ){ }∫∫∫∫∫∫ ⋅∇∇+×∇×∇−⋅∇∇+∇−=
)()(
2
tVtV
vduuupGvd
tD
uD
λµµρρ
OR
( ) ( )[ ]uupG
tD
uD
⋅∇+∇+×∇×∇−∇−= µλµρρ 2
SOLO
(2.6) CONSTITUTIVE RELATIONS
(2.6.1) NAVIER–STOKES EQUATIONS (CONTINUE)
(2.6.1.2)VECTORIAL DERIVATION (CONTINUE)
82. 82
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
VECTOR NOTATION CARTESIAN TENSOR NOTATION
CONSERVATION OF LINEAR MOMENTUM
( ) ( )[ ]∇ ⋅ = − ∇ − ∇ × ∇ × + ∇ + ∇ ⋅~σ µ µ λp u u
2 ( )
++
++−=
k
k
ii
k
k
i
iii
ik
x
u
xx
u
x
u
xx
p
x ∂
∂
λµ
∂
∂
∂
∂
∂
∂
µ
∂
∂
∂
∂
∂
σ∂
2
( ) ( )[ ]
ρ ρ σ
ρ µ µ λ
Du
Dt
G
G p u u
= + ∇ ⋅
= − ∇ − ∇ × ∇ × + ∇ + ∇ ⋅
~
2 ( )
++
++−=
+=
k
k
ii
k
k
i
ii
i
i
ik
i
i
x
u
xx
u
x
u
xx
p
G
x
G
tD
uD
∂
∂
λµ
∂
∂
∂
∂
∂
∂
µ
∂
∂
∂
∂
ρ
∂
σ∂
ρρ
2
USING STOKES ASSUMPTION tr ~τ λ µ= ⇒ = −0
2
3
( )
⋅∇∇+×∇×∇−∇−=
⋅∇+=
uupG
G
tD
uD
µµρ
σρρ
3
4
~
+
++−=
+=
k
k
ki
k
k
i
ii
i
i
ik
i
i
x
u
i
xx
u
x
u
xx
p
G
x
G
tD
uD
∂
∂
µ
∂
∂
∂
∂
∂
∂
µ
∂
∂
∂
∂
ρ
∂
σ∂
ρρ
3
4
SOLO
(2.6) CONSTITUTIVE RELATIONS
(2.6.1) NAVIER–STOKES EQUATIONS (CONTINUE)
83. 83
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
VECTOR NOTATION CARTESIAN TENSOR NOTATION
Euler Equations are obtained by assuming Inviscid Flow
0
3
2
0~ =−=⇒= µλτ
pG
tD
uD
∇−=
ρρ
i
i
i
x
p
G
tD
uD
∂
∂
ρρ −=
SOLO
(2.6) CONSTITUTIVE RELATIONS
(2.6.2) EULER EQUATIONS
Leonhard Euler
(1707-1783)
pGuu
t
u
∇−=
∇⋅+
∂
∂
ρρ
i
i
k
i
k
i
x
p
G
x
u
u
t
u
∂
∂
ρρ −=
∂
∂
+
∂
∂
or or
84. 84
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.6.1.3) COMPUTATION
BUT
Φ
Φ = = +
= +
=
=
τ
∂
∂
τ
∂
∂
τ
∂
∂
τ
∂
∂
∂
∂
τ
τ τ
ik
i
k
ik
i
k
ki
k
i
ik
i
k
k
i
ik ik
u
x
u
x
u
x
u
x
u
x
D
ik ki1
2
1
2
τ µ λ δik ik kk ikD D= +2
HENCE ( )Φ = = +τ µ λ δik ik ik kk ik ikD D D D2
OR
( )[ ] ( )[ ]
( )[ ] ( )
Φ = + + + + + + +
+ + + + + + + + + + ⇒
=
2 2
2 2
11 11 22 33 11 22 11 22 33 22
33 11 22 33 33 12
2
21
2
13
2
31
2
23
2
32
2
µ λ µ λ
µ λ µ
D D D D D D D D D D
D D D D D D D D D D D
D Dij ji
( ) ( )Φ = + + + + + + + +2 2 2 211
2
22
2
33
2
12
2
13
2
23
2
11 22 33
2
µ λD D D D D D D D DOR
SOLO
(2.6) CONSTITUTIVE RELATIONS
(2.6.1) NAVIER–STOKES EQUATIONS (CONTINUE)
85. 85
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.6.1.3) COMPUTATION (CONTINUE)
USING STOKES ASSUMPTION: tr ~τ λ µ= ⇒ = −0
2
3
Φ
( ) ( )Φ = + + + + + + + +2 2 2 211
2
22
2
33
2
12
2
13
2
23
2
11 22 33
2
µ λD D D D D D D D D
( ) ( ) ( )
( )
( )
( )
Φ = + + − + + + + +
+ + + − + +
+ +
2
3
4
3
4
3
4
2
3
11 22 33
2
11 22 11 33 22 33 11
2
22
2
33
2
2
12
2
13
2
23
2
11 22 33
2
11
2
22
2
33
2
µ µ µ
µ
µ
λ
µ
D D D D D D D D D D D D
D D D D D D
D D D
OR
( ) ( ) ( )[ ] ( )Φ = − + − + − + + + >
2
3
4 011 22
2
11 33
2
22 33
2
12
2
13
2
23
2µ
µD D D D D D D D D
SOLO
(2.6) CONSTITUTIVE RELATIONS
(2.6.1) NAVIER–STOKES EQUATIONS (CONTINUE)
86. 86
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.6.1.4) ENTROPY AND VORTICITY
From (C.L.M.)
or
( ) ( )[ ]Du
Dt
u
t
u
u u G p u u
= + ∇
− × ∇ × = − ∇ − ∇ × ∇ × + ∇ + ∇ ⋅
∂
∂ ρ ρ
µ
ρ
λ µ
2
2
1 1 1
2
GIBBS EQUATION: T d s d h
d p
= −
ρ
∀
+⋅∇−
+⋅∇=
+⋅∇
→→→→
tld
pd
td
t
p
ldp
hd
td
t
h
ldh
sd
td
t
s
ldsT &
1
∂
∂
ρ∂
∂
∂
∂
Since this is true for all d l t
→
&
T s h
p
T
s
t
h
t
p
t
∇ = ∇ −
∇
= −
ρ
∂
∂
∂
∂ ρ
∂
∂
&
1
SOLO
(2.6) CONSTITUTIVE RELATIONS
(2.6.1) NAVIER–STOKES EQUATIONS (CONTINUE)
Josiah Willard Gibbs
(1903 – 1839)
87. 87
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.6.1.4) ENTROPY AND VORTICITY
from (C.L.M.)
or
GIBBS EQUATION: T d s d h
d p
= −
ρ
∀
+⋅∇−
+⋅∇=
+⋅∇
→→→→
tld
pd
td
t
p
ldp
hd
td
t
h
ldh
sd
td
t
s
ldsT &
1
∂
∂
ρ∂
∂
∂
∂
Since this is true for all d l t
→
&
T s h
p
T
s
t
h
t
p
t
∇ = ∇ −
∇
= −
ρ
∂
∂
∂
∂ ρ
∂
∂
&
1
SOLO
hsTG
p
Guuu
t
u
II
III
II
I
,,
,,,
,
2
,
~~
2
1
∇−∇+
⋅∇
+=
⋅∇
+
∇
−=
×∇×−
∇+
ρ
τ
ρ
τ
ρ∂
∂
ρ
p
hsT
dlpdp
dlhdh
dlsds
∇
−∇=∇→
⋅∇=
⋅∇=
⋅∇=
88. 88
Luigi Crocco
1909-1986
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.6.1.4) ENTROPY AND VORTICITY (CONTINUE)
Define
Let take the CURL of this equation
Vorticityu
×∇≡Ω
If , then from (C.L.M.) we get:
G = −∇Ψ
CRROCO’s EQUATION (1937)
( ) ( )
⋅∇×∇+
Ψ++∇×∇−∇×∇=×Ω×∇+×∇
Ω
τ
ρ∂
∂ ~1
0
2
2
u
hsTuu
t
SOLO
ρ
τ
∂
∂ ~
2
1 ,2
,,
⋅∇
+
Ψ++∇−∇=×Ω+
I
II
I
uhsTu
t
u
hsTGuuu
t
u
II
I
II
I
,,
,
,
2
,
~
2
1
∇−∇+
⋅∇
+=
×∇×−
∇+
ρ
τ
∂
∂
From
90. 90
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.6) CONSTITUTIVE RELATIONS
(2.6.1) NAVIER–STOKES EQUATIONS (CONTINUE)
(2.6.1.4) ENTROPY AND VORTICITY (CONTINUE)
( ) ( ) τ
ρ
~1
⋅∇×
∇−∇×∇+⋅∇Ω−∇⋅Ω=
Ω
sTuu
tD
D
FLUID WITHOUT VORTICITY WILL REMAIN FOREVER WITHOUT
VORTICITY IN ABSENSE OF ENTROPY GRADIENTS OR VISCOUS
FORCES
- FOR AN INVISCID FLUID ( )λ µ τ= = → =0 0~ ~
( ) ( ) sTuu
tD
D
INVISCID
∇×∇+⋅∇Ω−∇⋅Ω=
Ω =
0
~~τ
- FOR AN HOMENTROPIC FLUID
INITIALLY AT REST
s const everywhere i e s
s
t
. ; . . &∇ = =
0 0
∂
∂( )( )
Ω 0 0=
( )
D
Dt
s
Ω
Ω= = = ∇ =0 0 0 0 0~ ~
, ,τ
SOLO
Return to Table of Content
91. 91
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.6) CONSTITUTIVE RELATIONS
(2.6.2) STATE EQUATION
p - PRESSURE (FORCE / SURFACE)
V - VOLUME OF GAS
M - MASS OF GAS
R - 8314
- 286.9
T - GAS TEMPERATURE
- GAS DENSITY
[ ]m3
[ ]kg
[ ]J kg mol Ko
/ ( )⋅
[ ]J kg Ko
/ ( )⋅R
[ ]kgmol /−η
[ ]o
K
[ ]kg m/ 3
ρ
[ ]2
/ mN
IDEAL GAS
TRMVp η=
TMVp R=
DEFINE: ρ
ρ
= = =
∆ ∆M
V
v
V
M
&
1
pv T= R
p T= ρ R
OR
SOLO
92. 92
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
IDEAL GAS TMVp R=
SOLO
(2.6) CONSTITUTIVE RELATIONS
(2.6.2) STATE EQUATION
Return to Table of Content
93. 93
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.6) CONSTITUTIVE RELATIONS
(2.6.3) THERMALLY PERFECT GAS AND CALORICALLLY PERFECT GAS
A THERMALLY PERFECT GAS IS DEFINED AS A GAS FOR WHICH THE
INTERNAL ENERGY e IS A FUNCTION ONLY OF THE TEMPERATURE T.
( ) ( )h e T p e T RT h T= + = + =/ ( )ρ THERMALLY PERFECT GAS
DEFINE
C
C
v
V V
p
p p p p
e
T
q
T
h
T
de pdv v d p
d T
de pdv
d T
dq
d T
= =
= = = =
+ +
+
∆
∆
∂
∂
∂
∂
∂
∂
A CALORICALLY PERFECT GAS IS DEFINED AS A GAS FOR WHICH Cv
IS CONSTANT CALORICALLY PERFECT GASe C Tv=
SOLO
94. 94
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.6) CONSTITUTIVE RELATIONS
(2.6.3) CALORICALLLY PERFECT GAS (CONTINUE)
A CALORICALLY PERFECT GAS IS DEFINED AS A GAS FOR WHICH Cv
IS CONSTANT CALORICALLY PERFECT GASe C Tv=
FOR A CALORICALLY PERFECT GAS
( )h C T RT C R T C T C C Rv v p p v= + = + = → = +
γ
γ
γ γ
= ⇒ =
−
⇒ =
−
= + = −∆ C
C
C R C
Rp
v
C C R
p
R C C
v
p v p v
1 1
γ air = 14.
SOLO
95. 95
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.6) CONSTITUTIVE RELATIONS
(2.6.3) CALORICALLLY PERFECT GAS (CONTINUE)
(2.6.3.1) ENTROPY CALCULATIONS FOR A CALORICALLLY PERFECT GAS
pv T= R p T= ρ R IDEAL GAS
( )
ds
de pdv
T
de pdv vdp vdp
T
dh vdp
T
=
+
=
+ + −
=
−∆
ds C
dT
T
R
dv
v
s s C
T
T
R
v
v
C
T
T
Rv v v= + → − = + = −2 1
2
1
2
1
2
1
2
1
ln ln ln ln
ρ
ρ
1
2
1
2
12 lnln
p
p
R
T
T
Css
p
dp
R
T
dT
Cds pp −=−→−=
s s C
p
p
R C
p
p
Cv v p2 1
2
1
1
2
2
1
2
1
2
1
− = ⋅
− = −ln ln ln ln
ρ
ρ
ρ
ρ
ρ
ρ
ENTROPY
SOLO
96. 96
FLUID DYNAMICS
2. BASIC LAWS IN FLUID DYNAMICS (CONTINUE)
(2.6) CONSTITUTIVE RELATIONS
(2.6.3) CALORICALLLY PERFECT GAS (CONTINUE)
(2.6.3.1) ENTROPY CALCULATIONS FOR A CALORICALLLY PERFECT GAS
p
p
T
T
e
T
T
e
p
p
T
T
C
R s s
R
s s
R
isentropic
s s
p
2
1
2
1
2
1
1
2
1
2
1
12 1 2 1 2 1
=
=
=
−
− − −
− = −
⇒
γ
γ
γ
γ
ρ
ρ
ρ
ρ
γ
γ γ
2
1
2
1
2
1
1
1
2
1
2
1
1
12 1 2 1 2 1
=
=
=
−
− − −
− = −
⇒
T
T
e
T
T
e
T
T
C
R s s
R
s s
R
isentropic
s s
v
p
p
e e
p
p
C
C s s
R
s s
R
isentropic
s s
p
v
2
1
2
1
2
1
2
1
2
1
2 1 2 1 2 1
=
=
=
−
−
−
− =
⇒
ρ
ρ
ρ
ρ
ρ
ρ
γ γ
T
T
h
h
p
p
e
p
p
e
T
T
h
h
p
p
s s
C
s s
C
isentropic
s s
v p2
1
2
1
2
1
2
1
2
1
1
2
1
1
2
1
2
1
2
1
1
2
1
12 1 2 1
2 1
= = ⋅ =
=
= =
=
−
−
−
− −
−
=
−
−
⇒
ρ
ρ
ρ
ρ
ρ
ρ
γ
γ
γ
γ
γ
γ
ISENTROPIC CHAIN
SOLO
Return to Table of Content
98. 98
SOLO
Dimensionless Equations
Dimensionless Variables are:
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
Field Equations
(C.M.): ( )
00
0
0
U
l
u
t ρ
ρ
∂
ρ∂
=⋅∇+
( ) 2
00
0
~
3
4
U
l
uupGuu
t
u
ρ
µµρ
∂
∂
ρ
τ
⋅∇
⋅∇∇+×∇×∇−∇−=
∇⋅+(C.L.M.):
( ) ( ) 3
00
0~
U
l
Tk
t
Q
uGu
t
p
Hu
t
H
q
ρ∂
∂
ρτ
∂
∂
ρ
∇⋅∇−+⋅+⋅⋅∇+=
∇⋅+
∂
∂
(C.E.):
( )
( )
( ) 0
/
/
00
0
00
0
=
⋅∇+
U
u
l
lUt
ρ
ρ
∂
ρρ∂
( )
( ) ( )
( ) ( )
⋅∇∇
+
×∇×∇
−
∇−=
∇⋅+
0
00
000
0
0
0
0
0
000
0
2
00
02
0
0
00
0
000
0
0
3
4
/
/
U
u
ll
UlU
u
ll
Ul
U
p
l
g
G
U
lg
U
u
l
U
u
lUt
Uu
ρ
µ
µ
µ
ρ
µ
ρρ
ρ
∂
∂
ρ
ρ
( ) ( )
( )
( )
( ) ( )
∇⋅∇
−+⋅+
⋅⋅∇+
∂
∂
=
2
0
0
0
0
0
0
000
0
2
00000
2
0
0
0
2
00
02
0000
2
00000 /
~
// U
CT
l
k
k
l
C
k
UlU
Q
lUtU
u
g
G
U
gl
U
u
U
l
U
p
lUtU
H
lUtD
D p
pµρ
µ
∂
∂
ρ
ρ
ρ
τ
ρρρ
ρ
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 =
Reference Quantities: ρ0(density), U0(velocity), l0 (length), g (gravity), μ0 (viscosity),
k0 (Fourier Constant), λ0 (mean free path)
0/
~
λλλ =
99. 99
SOLO
Dimensionless Equations
Dimentionless 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
=
100. 100
SOLO
Dimensionless Equations
Constitutive Relations
TRp ρ=
2
2
1
uTCH p +=
Tkq ∇−=
TCh p=
−
== 2
00
2
00
2
00
1
U
TC
U
TC
C
R
U
p pp
p ρ
ρ
γ
γ
ρ
ρ
ρ
=
2
0
2
0 U
TC
U
h p
2
0
2
0
2
0 2
1
+
=
U
u
U
TC
U
H p
( )
∇
−= 2
0
0
00
0
000
0
3
00 U
TC
l
k
k
C
k
UlU
q p
p µρ
µ
ρ
( ) [ ]3
3
2~ Iuuu T
⋅∇−∇+∇= µµτ [ ]3
0
0
0000
0
0
0
0
0
0000
0
00 3
2~
I
U
u
l
UlU
u
l
U
u
l
UlU
T
⋅∇
−
∇+∇
=
µ
µ
ρ
µ
µ
µ
ρ
µ
ρ
τ
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 =
101. 101
SOLO
Dimensionless Equations
Dimensionless Constitutive Relations
2~
2
1~~
uTH +=
Tp
~~1~ ρ
γ
γ −
= Ideal Gas
( ) [ ]3
~~~
3
2~~~~~~~ Iu
R
uu
R e
T
e
⋅∇−∇+∇=
µµ
τ Navier-Stokes
Th
~~
= Calorically Perfect Gas
Tk
PR
q
re
~~~11~
∇−=
Fourier Law
Reynolds:
0
000
µ
ρ lU
Re =
Prandtl:
0
0
k
C
P
p
r
µ
=
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 =
Return to Table of Content
102. 102
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
103. 103
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
behaviour of flows above Mach 1. Sharp edges, thin aerofoil-
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
105. 105
where
ρ = air density
V = true speed
l = characteristic length
μ = absolute (dynamic) viscosity
υ = kinematic viscosity
Reynolds:
υµ
ρ ρ
µ
υ
lVlV
Re
=
==
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
106. 106
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
107. 107
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 these two types of Boundary-Layer Flow
SOLO AERODYNAMICS
108. 108
Normalized Velocity profiles within a Boundary-Layer, comparison between
Laminar and Turbulent Flow.
SOLO
Boundary-Layer
AERODYNAMICS
110. 110
Relative Drag Force as a Function of Reynolds Number (Viscosity)
AERODYNAMICS
Drag CD0 due to
Flow Separation
SOLO
111. 111
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
112. 112
Parasite Drag
Pressure Differential,
Viscous Shear Stress,
and Separation
AERODYNAMICS
Relative Drag Force as a Function of Reynolds Number (Viscosity)
DragFrictionSkin
ET
EL
ll
ET
EL
uu
DragPressure
ET
EL
ll
ET
EL
uu
sdfsdf
sdpsdpD
∫∫
∫∫
++
+−=
..
..
..
..
..
..
..
..
coscos
sinsin
θθ
θθ
SOLO
113. 113
AERODYNAMICS
Relative Drag Force as a Function of Reynolds Number (Viscosity)
• Blunt Body: Most of Drag
is Pressure Drag.
• Streamlined Body:
Most of Drag is Skin
Friction Drag.
SOLO
116. 116
AERODYNAMICS
Relative Drag Force as a Function of Reynolds Number (Viscosity)
SOLO
Variation of total skin-friction coefficient with Reynolds number for a
smooth, flat plate.[From Dommasch, et al. (1967).]
117. 117
Typical Effect of Reynolds Number on Parasitic Drag
Flow may stay attached
farther at high Re,
reducing the drag
AERODYNAMICSSOLO
Return to Table of Content
118. 118
FluidsSOLO
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.
119. 119
FluidsSOLO
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 =
120. 120
FluidsSOLO
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 =
121. 121
FluidsSOLO
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 =
122. FluidsSOLO
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
Return to Table of Content
123. 123
AERODYNAMICS
Fluid flow is characterized by a velocity vector field in
three-dimensional space, within the framework of
continuum mechanics. Streamlines, Streaklines and
Pathlines are field lines resulting from this vector field
description of the flow. They differ only when the flow
changes with time: that is, when the flow is not steady.
• Streamlines are a family of curves that are
instantaneously tangent to the velocity vector of the
flow. These show the direction a fluid element will
travel in at any point in time.
• Streaklines are the locus of points of all the fluid
particles that have passed continuously through a
particular spatial point in the past. Dye steadily injected
into the fluid at a fixed point extends along a streakline
• Pathlines are the trajectories that individual fluid particles follow. These can be thought of as
a "recording" of the path a fluid element in the flow takes over a certain period. The direction
the path takes will be determined by the streamlines of the fluid at each moment in time.
• Timelines are the lines formed by a set of fluid particles that were marked at a previous
instant in time, creating a line or a curve that is displaced in time as the particles move.
The red particle moves in a flowing fluid; its pathline is
traced in red; the tip of the trail of blue ink released from
the origin follows the particle, but unlike the static pathline
(which records the earlier motion of the dot), ink released
after the red dot departs continues to move up with the flow.
(This is a streakline.) The dashed lines represent contours of
the velocity field (streamlines), showing the motion of the
whole field at the same time. (See high resolution version.
Flow Description
SOLO
124. 124
3-D Flow
Flow Description
SOLO
Steady Motion: If at various points of the flow field quantities (velocity, density, pressure)
associated with the fluid flow remain unchanged with time, the motion is said to be steady.
( ) ( ) ( )zyxppzyxzyxuu ,,,,,,,, === ρρ
Unsteady Motion: If at various points of the flow field quantities (velocity, density, pressure)
associated with the fluid flow change with time, the motion is said to be unsteady.
( ) ( ) ( )tzyxpptzyxtzyxuu ,,,,,,,,,,, === ρρ
Path Line: The curve described in space by a moving fluid element is known as its trajectory
or path line.
tt
tt ∆+
t
tt ∆+
tt ∆+ 2
t
tt ∆+
tt ∆+ 2
Path Line (steady flow)
t
tt ∆+
t
tt ∆+ 2
tt ∆+
t
Path Line (unsteady flow)
tt ∆+ 2
tt ∆+
t
125. 125
3-D Flow
Flow Description
SOLO
Path Line: The curve described in space by a moving fluid element is known as its trajectory
or path line.
t
tt ∆+ tt ∆+ 2
Streamlines: The family of curves such that each curve is tangent at each point to the
velocity direction at that point are called streamlines.
Consider the coordinate of a point P and the direction of the streamline passing
through this point. If is the velocity vector of the flow passing through P at a time t,
then and parallel, or:
r
rd
u
u
rd
0=×urd
( )
( )
( )
0
1
1
1111
=
−
−
−
=
zdyudxv
ydxwdzu
xdzvdyw
wvu
dzdydx
zyx
w
zd
v
yd
u
xd
==
Cartesian
t
u
r
rd
126. 126
3-D Flow
Flow Description
SOLO
Path Line: The curve described in space by a moving fluid element is known as its trajectory
or path line.
Streamlines: The family of curves such that each curve is tangent at each point to the
velocity direction at that point are called streamlines.
( ) ( ) ( )tzyxw
zd
tzyxv
yd
tzyxu
xd
,,,,,,,,,
==
t
u
r
rd
Those are two independent differential equations for a streamline. Given a point
the streamline is defined from those equations.( )0000 ,,, tzyxr
( )
( ) ( )
( )
( ) ( )tzyxw
zd
tzyxv
yd
tzyxv
yd
tzyxu
xd
,,,,,,
2
,,,,,,
1
=
=
( ) ( ) ( )
( ) ( ) ( ) 0,,,,,,,,,
0,,,,,,,,,
222
111
=++
=++
zdtzyxcydtzyxbxdtzyxa
zdtzyxcydtzyxbxdtzyxa
( ) ( )
( ) ( )21
21
22
11
•+•
•+•
βα
βα
0
22
11
≠
βα
βα
Pfaffian Differential Equations
For a given a point the solution of those equations is of the form:( )0000 ,,, tzyxr
( )
( ) 2,,,
1,,,
02
01
consttzyx
consttzyx
=
=
ψ
ψ
u
( )0
tr
rd
0t
( ) 11 cr =
ψ
( ) 22 cr =
ψ
Streamline
Those are two surfaces, the
intersection of which is the
streamline.
127. 127
3-D Flow
Flow Description
SOLO
Path Line: The curve described in space by a moving fluid element is known as its trajectory
or path line.
Streamlines: The family of curves such that each curve is tangent at each point to the
velocity direction at that point are called streamlines.
( ) ( ) ( )tzyxw
zd
tzyxv
yd
tzyxu
xd
,,,,,,,,,
==
t
u
r
rd
For a given a point the solution of those equations is of the form:( )0000 ,,, tzyxr
( )
( ) 2,,,
1,,,
02
01
consttzyx
consttzyx
=
=
ψ
ψ
u
( )0
tr
rd
0
t
( ) 11 cr =
ψ
( ) 22 cr =
ψ
Streamline
Those are two surfaces, the
intersection of which is the
streamline.
The streamline is perpendicular to the gradients (normals) of those two surfaces.
( ) ( ) ( )0201 ,, trtrVr
ψψµ ∇×∇=
where μ is a factor that must satisfy the following constraint.
( )( ) ( ) ( ) 0,, 0201 =∇×∇⋅∇=⋅∇ trtrVr
ψψµ
Return to Table of Content
128. 128
AERODYNAMICS
Streamlines, Streaklines, and Pathlines
Mathematical description
Streamlines
If the components of the velocity are written and those of the streamline as
we deduce
which shows that the curves are parallel to the velocity vector
Pathlines
Streaklines
where, is the velocity of a particle P at location and time t . The parameter , parametrizes the
streakline and 0 ≤ τP ≤ t0 , where t0 is a time of interest .
The suffix P indicates that we are following the motion of a fluid particle. Note that at point
the curve is parallel to the flow velocity vector where the velocity vector is evaluated at
the position of the particle at that time t .
SOLO
129. 129
∞V
Airfoil Pressure Field variation with α
AERODYNAMICS
Airfoil Velocity Field variation with αAirfoil Streamline variation with αAirfoil Streakline with α
Streamlines, Streaklines, and Pathlines
SOLO
134. 134
3-D Inviscid Incompressible Flow
Circulation
SOLO
Circulation Definition:
tV ∆
( ) tVV ∆∆+
S∆
Sn ∆1
V
×∇
t
r
∆
ttr ∆+∆
t
C
tt
C ∆+
∫ ⋅=Γ
C
rdV
:
Material Derivative of the Circulation
( )∫∫∫ ⋅+⋅=
⋅=
Γ
CCC
rd
tD
D
Vrd
tD
VD
rdV
tD
D
tD
D
From the Figure we can see that:
( ) tVrtVVr ttt
∆+∆=∆∆++∆ ∆+
( ) Vdrd
tD
D
V
t
rr t
ttt
=→∆=
∆
∆−∆ →∆
∆+
0
( ) 0
2
2
=
=⋅=⋅ ∫∫∫ CCC
V
dVdVrd
tD
D
V
Therefore:
∫ ⋅=
Γ
C
rd
tD
VD
tD
D
integral of an exact differential on a closed curve.
C – a closed curve
135. 135
3-D Inviscid Incompressible FlowSOLO
tV ∆
( ) tVV ∆∆+
S∆
Sn ∆1
V
×∇
t
r
∆
ttr ∆+∆
t
C
tt
C ∆+
S
∫ ⋅=Γ
tC
rdV
:
Material Derivative of the Circulation (second derivation)
Subtract those equations:
tVrdSn t
∆×=∆
1
( )∫∆+
⋅∆+=Γ∆+Γ
ttC
rdVV
:
( ) ( )∫∫∫∫ ∆⋅×∇=⋅∆+−⋅=Γ∆−
∆+ S
TheoremsStoke
CC
SnVrdVVrdV
ttt
1
'
S is the surface bounded by the curves Ct and C t+Δ t
( ) ( ) ( ) tVVrdtVrdVSnV
S
t
S
t
S
∆
×∇×⋅=∆×⋅×∇=∆⋅×∇=Γ∆− ∫∫∫∫∫∫
1
td
d
ttd
rd
t
V
ttD
D rdd
Γ
+
∂
Γ∂
=Γ∇⋅+
∂
Γ∂
=Γ∇⋅+
∂
Γ∂
=
Γ Γ∇⋅=Γ
Computation of:
∫ ⋅
∂
∂
=
∂
Γ∂
tC
rd
t
V
t
Computation of:
td
d Γ
136. 136
3-D Inviscid Incompressible FlowSOLO
tV ∆
( ) tVV ∆∆+
S∆
Sn ∆1
V
×∇
t
r
∆
tt
r ∆+
∆
t
C
tt
C ∆+
Material Derivative of the Circulation (second derivation)
( ) tVVrd
S
t
∆
×∇×⋅=Γ∆− ∫∫
When Δ t → 0 the surface S shrinks to the curve C=Ct and
the surface integral transforms to a curvilinear integral:
( ) ( ) ( )∫∫∫∫∫ ∇⋅⋅+
−=∇⋅⋅+
∇⋅−=×∇×⋅−=
Γ
C
t
CC
t
C
t
C
t
VVrd
V
dVVrd
V
rdVVrd
td
d
0
22
22
Computation of: (continue)
td
d Γ
Finally we obtain:
( ) ∫∫∫ ⋅=∇⋅⋅+⋅
∂
∂
=
Γ
+
∂
Γ∂
=
Γ
tt CC
t
C
rd
tD
VD
VVrdrd
t
V
td
d
ttD
D
137. 137
3-D Inviscid Incompressible FlowSOLO
tV ∆
( ) tVV ∆∆+
S∆
Sn ∆1
V
×∇
t
r
∆
tt
r ∆+
∆
t
C
tt
C ∆+
Material Derivative of the Circulation
We obtained:
∫ ⋅=
Γ
tC
rd
tD
VD
tD
D
Use C.L.M.: hsT
p
VV
t
V
tD
VD
II
I
G
II
II
,,
,
,,
~
∇−∇+
⋅∇
+Ψ∇=
∇⋅+=
τ
∂
∂
( ) ( )
0
,
,,
,
,
~~
∫∫∫∫ −Ψ+⋅
⋅∇
+∇=⋅∇−Ψ∇+⋅
⋅∇
+∇=
Γ
tttt CC
I
I
C
I
C
I
I
I
hddrd
p
sTrdhrd
p
sT
tD
D ττ
to obtain:
∫ ⋅
⋅∇
+∇=
Γ
tC
I
I
I
rd
p
sT
tD
D τ~
,
,
or:
Kelvin’s Theorem
William Thomson
Lord Kelvin
(1824-1907)
In an inviscid , isentropic flow d s = 0 with conservative
body forces the circulation Γ around a closed fluid line
remains constant with respect to time.
0
~~ =τ
Ψ∇=G
Return to Table of Content
1869
138. 138
3-D Inviscid Incompressible FlowSOLO
Circulation Definition: ∫ ⋅=Γ
C
rdV
:
C – a closed curve
Biot-Savart Formula
1820
Jean-Baptiste Biot
1774 - 1862
VorticityV
×∇≡Ω
∫ −
Ω
=
Space
dV
sr
A
π4
1
( )lddSn
sr
Ad
⋅
−
Ω
=
π4
1
The contribution of a length dl of the Vortex Filament
to isA
∫∫∫∫∫ ⋅Ω=⋅×∇=⋅=Γ
SS
Stokes
C
SdnSdnVrdV
:
If the Flow is Incompressible 0=⋅∇ u
so we can write , where is the Vector Potential. We are free to
choose so we choose it to satisfy .
AV
×∇=
A
A
0=⋅∇ A
We obtain the Poisson Equation that defines the Vector Potential A
Ω−=∇
A2
Poisson Equation Solution( ) ∫ −
Ω
=
Space
dv
sr
rA
π4
1
Félix Savart
1791 - 1841
Biot-Savart Formula
139. 139
3-D Inviscid Incompressible FlowSOLO
Circulation Definition: ∫ ⋅=Γ
C
rdV
:
C – a closed curve
Biot-Savart Formula (continue - 1)
1820
Jean-Baptiste Biot
1774 - 1862
VorticityV
×∇≡Ω
( )lddSn
sr
Ad
⋅
−
Ω
=
π4
1
We found
∫∫∫∫∫ ⋅Ω=⋅×∇=⋅=Γ
SS
Stokes
C
SdnSdnVrdV
:
also we have dlld
Ω
Ω
=
( ) ( ) ∫∫∫∫∫ ×
−
∇⋅Ω=⋅
−
Ω
×∇=×∇=
Γ
Ω
Ω
=
ld
sr
dSnlddSn
sr
AdrV r
S
dlld
v
rr
1
4
1
4
1
ππ
( ) ( )
∫ −
−×Γ
= 3
4 sr
srld
rV
π Biot-Savart Formula
Félix Savart
1791 - 1841
Biot-Savart Formula
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J.J. Bertin, M.L. Smith, “Aerodynamics for Engineering”, Prentice-Hall, 1979
H. Schlichting, E. Truckenbrodt, “Aerodynamics of Airpline”, 1969, McGraw-Hill, 1979, pg.113
J.J. Bertin, M.L. Smith, “Aerodynamics for Engineering”, Prentice-Hall, 1979, pg. 165
J.J. Bertin, M.L. Smith, “Aerodynamics for Engineering”, Prentice-Hall, 1979
H. Schlichting, E. Truckenbrodt, “Aerodynamics of Airpline”, 1969, McGraw-Hill, 1979
J.J. Bertin, M.L. Smith, “Aerodynamics for Engineering”, Prentice-Hall, 1979
H. Schlichting, E. Truckenbrodt, “Aerodynamics of Airpline”, 1969, McGraw-Hill, 1979
J.J. Bertin, M.L. Smith, “Aerodynamics for Engineering”, Prentice-Hall, 1979
H. Schlichting, E. Truckenbrodt, “Aerodynamics of Airpline”, 1969, McGraw-Hill, 1979, pg.119
J.J. Bertin, M.L. Smith, “Aerodynamics for Engineering”, Prentice-Hall, 1979,pg.170
H. Schlichting, E. Truckenbrodt, “Aerodynamics of Airpline”, 1969, McGraw-Hill, 1979, pg.119
J.J. Bertin, M.L. Smith, “Aerodynamics for Engineering”, Prentice-Hall, 1979,pg.170
H. Schlichting, E. Truckenbrodt, “Aerodynamics of Airpline”, 1969, McGraw-Hill, 1979, pg.119
J.J. Bertin, M.L. Smith, “Aerodynamics for Engineering”, Prentice-Hall, 1979,pg.170
H. Schlichting, E. Truckenbrodt, “Aerodynamics of Airpline”, 1969, McGraw-Hill, 1979, pg.119
J.J. Bertin, M.L. Smith, “Aerodynamics for Engineering”, Prentice-Hall, 1979,pg.170
H. Schlichting, E. Truckenbrodt, “Aerodynamics of Airpline”, 1969, McGraw-Hill, 1979, pg.119
J.J. Bertin, M.L. Smith, “Aerodynamics for Engineering”, Prentice-Hall, 1979,pg.170
H. Schlichting, E. Truckenbrodt, “Aerodynamics of Airpline”, 1969, McGraw-Hill, 1979
J.J. Bertin, M.L. Smith, “Aerodynamics for Engineering”, Prentice-Hall, 1979
H. Schlichting, E. Truckenbrodt, “Aerodynamics of Airpline”, 1969, McGraw-Hill, 1979
J.J. Bertin, M.L. Smith, “Aerodynamics for Engineering”, Prentice-Hall, 1979
H. Schlichting, E. Truckenbrodt, “Aerodynamics of Airpline”, 1969, McGraw-Hill, 1979
J.J. Bertin, M.L. Smith, “Aerodynamics for Engineering”, Prentice-Hall, 1979
H. Schlichting, E. Truckenbrodt, “Aerodynamics of Airpline”, 1969, McGraw-Hill, 1979
J.J. Bertin, M.L. Smith, “Aerodynamics for Engineering”, Prentice-Hall, 1979
H. Schlichting, E. Truckenbrodt, “Aerodynamics of Airpline”, 1969, McGraw-Hill, 1979
J.J. Bertin, M.L. Smith, “Aerodynamics for Engineering”, Prentice-Hall, 1979
H. Schlichting, E. Truckenbrodt, “Aerodynamics of Airpline”, 1969, McGraw-Hill, 1979
J.J. Bertin, M.L. Smith, “Aerodynamics for Engineering”, Prentice-Hall, 1979
H. Schlichting, E. Truckenbrodt, “Aerodynamics of Airpline”, 1969, McGraw-Hill, 1979
J.J. Bertin, M.L. Smith, “Aerodynamics for Engineering”, Prentice-Hall, 1979
H. Schlichting, E. Truckenbrodt, “Aerodynamics of Airpline”, 1969, McGraw-Hill, 1979, pp.121-122
J.J. Bertin, M.L. Smith, “Aerodynamics for Engineering”, Prentice-Hall, 1979,pp.173-1975
http://en.wikipedia.org/wiki/Vortex_lattice_method
H. Schlichting, E. Truckenbrodt, “Aerodynamics of Airpline”, 1969, McGraw-Hill, 1979
J.J. Bertin, M.L. Smith, “Aerodynamics for Engineering”, Prentice-Hall, 1979
J.J. Bertin, R.M. Cummings, “Aerodynamics for Engineering”, Pearson Prentice-Hall, 1979, 1989, 1998, 2002, 2009
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http://www.dept.aoe.vt.edu/~mason/Mason_f/CAtxtChap4.pdf
H. Schlichting, E. Truckenbrodt, “Aerodynamics of Airpline”, 1969, McGraw-Hill, 1979
J.J. Bertin, M.L. Smith, “Aerodynamics for Engineering”, Prentice-Hall, 1979
J.J. Bertin, R.M. Cummings, “Aerodynamics for Engineering”, Pearson Prentice-Hall, 1979, 1989, 1998, 2002, 2009
http://www.dept.aoe.vt.edu/~mason/Mason_f/CAtxtChap6.pdf
http://www.dept.aoe.vt.edu/~mason/Mason_f/CAtxtChap4.pdf
Spiegel, M.R., “Complex Variables with an introduction to Conformal Mapping and its applications”, Schaum’s Outline Series, McGraw-Hill, 1964, pp.191-192
Spiegel, M.R., “Complex Variables with an introduction to Conformal Mapping and its applications”, Schaum’s Outline Series, McGraw-Hill, 1964, pp.191-192
Spiegel, M.R., “Complex Variables with an introduction to Conformal Mapping and its applications”, Schaum’s Outline Series, McGraw-Hill, 1964, pp.191-192
Spiegel, M.R., “Complex Variables with an introduction to Conformal Mapping and its applications”, Schaum’s Outline Series, McGraw-Hill, 1964, pp.201-202
Spiegel, M.R., “Complex Variables with an introduction to Conformal Mapping and its applications”, Schaum’s Outline Series, McGraw-Hill, 1964, pp.191-192
Spiegel, M.R., “Complex Variables with an introduction to Conformal Mapping and its applications”, Schaum’s Outline Series, McGraw-Hill, 1964, pp.191-192
L.J. Clancy, “Aerodynamics”, Pitman, 1978, Appendix I, pp. 589-592
K. Karamcheti, “Principles of Idea-Fluid Aerodynamics”, John Wiley & Sons, 1966, Appendix E , pp. 624-627
L.J. Clancy, “Aerodynamics”, Pitman, 1978, Appendix I, pp. 589-592
K. Karamcheti, “Principles of Idea-Fluid Aerodynamics”, John Wiley & Sons, 1966, Appendix E , pp. 624-627
L.J. Clancy, “Aerodynamics”, Pitman, 1978, Appendix I, pp. 589-592
K. Karamcheti, “Principles of Idea-Fluid Aerodynamics”, John Wiley & Sons, 1966, Appendix E , pp. 624-627