CALIBRATION is a documented comparison of the measurement device to be calibrated against a traceable reference standard or device
Need of calibration:
Making sure that instrument making consistent measurement and displaying the correct readings
Establishing the instruments reliability
Maintaining adherence to industry standards , govt regulations , quality assurance norms like current good manufacturing practice
Determining the precision , deviation , and reliability of measurements
Wind tunnels are large tubes with air blowing through them
Need of wind tunnel:
tunnels are used to replicate the actions of an object flying through the air or moving along the ground
researchers use wind tunnels to learn more about how aircraft will fly
the wind tunnel moves air around an object making it seem as if the object is really flying
CALIBRATION is a documented comparison of the measurement device to be calibrated against a traceable reference standard or device
Need of calibration:
Making sure that instrument making consistent measurement and displaying the correct readings
Establishing the instruments reliability
Maintaining adherence to industry standards , govt regulations , quality assurance norms like current good manufacturing practice
Determining the precision , deviation , and reliability of measurements
Wind tunnels are large tubes with air blowing through them
Need of wind tunnel:
tunnels are used to replicate the actions of an object flying through the air or moving along the ground
researchers use wind tunnels to learn more about how aircraft will fly
the wind tunnel moves air around an object making it seem as if the object is really flying
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
A brief description of Automobile wind tunnels, icing tunnels, and propeller tunnels are contained in this presentation. history, design, and operation of each wind tunnel contains in this presentation.
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.
The flow across an airfoil is studied for different angle of attack. The CFD analysis results are documented and studied for different angle of attack using fluent & gambit.
What are the elements of aircraft performance?
How much thrust do you need?
How fast and how slow can you fly?
#WikiCourses
http://wikicourses.wikispaces.com/Topic+Performance+of+aerospace+vehicles
Pressure Distribution on an Airfoil
The team conducted the experiment to determine the effects of pressure distribution on lift and pitching moment and the behavior of stall for laminar and turbulent boundary layers in the USNA Closed-Circuit Wing Tunnel (CCWT) with an NACA 65-012 airfoil at a Reynolds number of 1,000,000. The airfoil was tested in a clean configuration at angles of attack of 0, 5, 8, 10, and 12 degrees. Tape added to the leading edge tripped the boundary layer, and pressure distributions were taken at 8, 10, and 12 degrees angle of attack. Experimental results showed a suction peak at less than 1% of chord, providing a beneficial test article for contrast between smooth and laminar boundary layer behavior at the stall condition. The maximum lift coefficient for the clean airfoil was 0.9 at 10 degrees angle of attack, and tripped airfoil reached a maximum lift coefficient of 1.03 at 12 degrees angle of attack, a 14% increase. These data were 10% lower than the empirical airfoil data found in Theory of Wing Sections from Abbott and von Doenhoff. Pitching moment coefficient about the quarter chord remained near zero below stall as expected for a symmetrical airfoil, but rapidly became negative after stall for experimental and empirical data. The airfoil exhibited a leading edge stall for both laminar and turbulent boundary layers.
For Video Lecture of this presentation: https://youtu.be/NAjezfbWh4Y
The topics covered in this session are, drag, categories of drag, drag polar equation and drag polar graph, drag polar derivation, induced drag coefficient.
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
ME 438 Aerodynamics is a course taught by Dr. Bilal Siddiqui at DHA Suffa University. This set of lectures start from the basic and all the way to aerodynamic coefficients and center of pressure variations with angle of attack.
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
A brief description of Automobile wind tunnels, icing tunnels, and propeller tunnels are contained in this presentation. history, design, and operation of each wind tunnel contains in this presentation.
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.
The flow across an airfoil is studied for different angle of attack. The CFD analysis results are documented and studied for different angle of attack using fluent & gambit.
What are the elements of aircraft performance?
How much thrust do you need?
How fast and how slow can you fly?
#WikiCourses
http://wikicourses.wikispaces.com/Topic+Performance+of+aerospace+vehicles
Pressure Distribution on an Airfoil
The team conducted the experiment to determine the effects of pressure distribution on lift and pitching moment and the behavior of stall for laminar and turbulent boundary layers in the USNA Closed-Circuit Wing Tunnel (CCWT) with an NACA 65-012 airfoil at a Reynolds number of 1,000,000. The airfoil was tested in a clean configuration at angles of attack of 0, 5, 8, 10, and 12 degrees. Tape added to the leading edge tripped the boundary layer, and pressure distributions were taken at 8, 10, and 12 degrees angle of attack. Experimental results showed a suction peak at less than 1% of chord, providing a beneficial test article for contrast between smooth and laminar boundary layer behavior at the stall condition. The maximum lift coefficient for the clean airfoil was 0.9 at 10 degrees angle of attack, and tripped airfoil reached a maximum lift coefficient of 1.03 at 12 degrees angle of attack, a 14% increase. These data were 10% lower than the empirical airfoil data found in Theory of Wing Sections from Abbott and von Doenhoff. Pitching moment coefficient about the quarter chord remained near zero below stall as expected for a symmetrical airfoil, but rapidly became negative after stall for experimental and empirical data. The airfoil exhibited a leading edge stall for both laminar and turbulent boundary layers.
For Video Lecture of this presentation: https://youtu.be/NAjezfbWh4Y
The topics covered in this session are, drag, categories of drag, drag polar equation and drag polar graph, drag polar derivation, induced drag coefficient.
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
ME 438 Aerodynamics is a course taught by Dr. Bilal Siddiqui at DHA Suffa University. This set of lectures start from the basic and all the way to aerodynamic coefficients and center of pressure variations with angle of attack.
Design and Fabrication of Subsonic Wind TunnelIJMERJOURNAL
ABSTRACT: A Wind Tunnel is a tool used in aerodynamic research to study the effects of air moving past the solid objects. Wind tunnels were first as a means of studying vehicles (primarily airplanes) in free flight. A Wind tunnel is used to find the aerodynamics and also to measure drag and down force of airfoils. The wind tunnel is composed of a contraction cone, test section and diffuser, with nessary instrumentation to measure the drag and downforce acting on the vehicles. Our project aims at using hand fabricated wind tunnel to test aerodynamics of scaled models and also to calculate the drag in them. It is very important nowadays to consider the aerodynamics of any vehicles whiles designing, this helps in improving the efficiency and reduces the fuel consumption. With this hand fabricated wind tunnel it makes the checking of aerodynamics and calculation of drag for scaled models very easy. This reduces the time taken for designing and production
basic aerodynamic design consideration of automobile, importance of car aerodyanamic design, various aerodynamic devices use in car body,different tools require for anlysis of aerodynamic
Numerical Investigation of Single Stage of an Axial Flow Compressor for Effec...IJERA Editor
In present work, a compressor configuration is taken from literature which will be studied for aspect ratio (ratio between length of blade to chord length) influence over performance. Performance in the sense is pressure ratio of compressor. The aspect ratio of the blade is an important parameter and has a strong influence on the performance of axial flow compressor. There are so many literatures available on influence of design parameters of axial flow compressor over its performance. Few literatures only are available for effects of aspect ratio of blade over performance of compressor. A study is proposed to be carried out to verify the effect of aspect ratio on the performance of single stage subsonic compressor through ANSYS-CFX software. The analysis will be carried out for the constant tip diameter of the compressor rotor blade having an aspect ratio 1, 2 and 3 and to obtain the pressure loss and flow parameters of the compressor stage. Further increase in aspect ratio will lead to structural problem of compressor. Therefore, there will be optimum aspect ratio between 2 and 3. Simulation will be conducted to aspect ratios of 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8 and 2.9 to find optimum ratio using ANSYS-CFX commercial CFD software.
QinetiQ’s long-arm centrifuge facility enables astronauts and fast-jet pilots to train for launch and landing, monitoring their health and performance during G-exposure and G-acceleration. For more info @ http://www.qinetiq.com/services-products/air/Pages/air-test-facilities.aspx
PROJECT: TEST RIG FOR HYDRAULIC FLUID (A3987)
The test rig is used to test the anti-wear properties and the aging
behaviour of hydraulic fluids under defined and reproducible
conditions. For this purpose, a vane pump Vickers 35VQ25A-11*20
for ASTM D6973-2014 and a Bent Axis type axial piston pump
A2F10 for JCMAS P 045 are used as test objects. The subsequent
investigation of the wear inserts and oil condition then allows
conclusions about the performance of the tested fluids, especially
their ability to avoid wear and resist oxidation. The modern and
ergonomically designed test rig meets all the specifications of the
European Machinery Directive 2006/42/EG to a high standard or
equivalent Indian Standard. The test rig is used to determine the
wear characteristics and oxidation/ aging of non-petroleum and
petroleum hydraulic fluids. For this purpose, a rotary vane pump
generates a test pressure under specific boundary conditions. The
result obtained is the total mass loss from the cam ring and the ten
vanes (ASTM D6973-2014) after the test. For indicating oxidation
stability or aging behaviour of hydraulic fluids this test bench, uses a
bent axis pump A2FO10 and a pressure relief valve DBDS 10
K1X/400V as load at high temperatures. The test takes place under
the influence of air and a copper catalyst. This procedure allows for
an accelerated aging rate using a real hydraulic component. The test
rig parameters meet the specifications according to ASTM D6973-
2014 and JCMAS P 045. Additionally, it is capable of carrying out the
evaluation of hydraulic fluid for frictional characteristics and energy
efficiency performance under indigenously developed and
industrially simulated test methods by varying load, speed,
temperature, pressure, flow rate etc.
Experimental investigation of damping force of twin tube shock absorberIJERA Editor
A shock absorber is a mechanical device to damp shock impulse and convert kinetic energy into thermal energy. The damping effect of shock absorber depends on damping force and damping force is affected by various process parameters. In this analysis three process parameters damping diameter(A), number of holes(B) and suspension velocity(C) were considered and their effect on damping force of shock absorber was studied and accordingly suitable orthogonal array was selected by taguchi method. Experiment conducted on servo hydraulic testing machine and after conducting experiments damping force was measured and with the help of S/N ratio, ANOVA, Regression analysis optimum parameter values can be obtained and confirmation experiments was carried out. Twin tube shock absorber was used to carry out experimentation.
Solution includes design of systems architectures and mechanical and electrical installations, instrumentation of the integrated systems, and certification for ground and flight tests. visit for more info @ http://www.qinetiq.com/services-products/air/Pages/aircraft-system-integration-and-upgrades.aspx
CFD Based Investigation on Effects of Compression Surface At Fighter Aircraft...IJERA Editor
The purpose of the intake of an aircraft is to supply the engine with a proper airflow during various flight conditions. A good intake design is characterized by providing high pressure recovery and low distortion. Therefore it is essential to divert as much of the boundary layer as possible since it is a factor which affect the quality of the airflow. On aircrafts with engines installed on wing pylons, which is the most common configuration on transport and passenger aircraft, the inlet is short and leads directly to the engine and the pressure recovery is good. For engines that are integrated with the body, for example on fighter aircrafts, the airflow is travelling along the body of the aircraft before it reaches the air intake. A boundary layer builds up along the body, something which is not desirable, especially in the part of the flow that supplies the engines. The pressure recovery is lower because of this, something that has a negative effect upon engine thrust. There are, however, ways to prevent the boundary layer from entering the inlet, or at least to minimize the amount that does. It is common to use a boundary layer diverter. It affects the aircraft performance in so many ways. So, it needs some other provision or technology to overcome intake problem in fighter crafts. In the present work, a well-designed compression surface is installed in the entry of the engine intake to redirect boundary layer and create shock wave for getting desired flow in the compressor (When a flow crosses a shock wave, its velocity got reduced, which in term increases pressure). The compression surface is placed at the entry of the diffuser to perform the above mentioned operation. The work extents to, a comparative investigation is proposed for with and without compression surface. ANSYS-Fluent is a commercial CFD code which will be used for performing the simulation and the simulation configuration contains two different Mach speeds (0.7 & 2) with three different angles of attacks (0°, 7.5° and 15°). The simulation results are evaluated to find out pressure recovery in the engine intake between with and without compression surface.
6. 6
15 Hp. Dual
Centrifugal Blower
Exhaust
Exhaust
Louvers
for Speed
Adjustment
Test Section
18 inch Diameter
25 to 1 Contraction
Screens High Contraction Wind Tunnel
Top View
Diffuser
Open Return(Closed Section)
10. SUBSONIC TUNNELS
Low speed wind tunnels are used for
operations at very low mach
number(M<0.5), with speeds in the test
section up to 480 km/hThey may be of
open-return type with air moved by a
propulsion system.
10
14. TRANSONIC WIND TUNNELS
High subsonic wind tunnels (0.4 < M < 0.75)
or transonic wind tunnels (0.75 < M < 1.2)
are designed on the same principles as the
subsonic wind tunnels.
14
15. TRANSONIC WIND TUNNEL
Testing at transonic speeds presents
additional problems, mainly due to the
reflection of the shock waves from the walls
of the test section
15
16. 16
8x6 Functions & Capabilities
The 8x6 Foot Supersonic WindTunnel provides
customers with a Facility capable of testing large
scale aero propulsion hardware
Relative altitude 1000 - 35000 ft
Dynamic Pressure 3.6 - 4.8 x 106/f
Temperature 60 - 250oF
18. SUPERSONIC WIND TUNNELS
A supersonic wind tunnel is a wind tunnel
that produces supersonic speeds (1.2<M<5)
The Mach number and flow are determined
by the nozzle geometry.
18
22. HYPERSONIC WIND TUNNELS
A hypersonic wind tunnel is designed to
generate a hypersonic flow field in the
working section.
The speed of these tunnels vary from Mach
5 to 15.
22
25. AUTOMOBILE WIND TUNNELS
External flow tunnels - Used to study the
external flow through the chassis
Climatic tunnels - Used to evaluate the
performance of door systems, braking
systems etc. under various climatic
conditions.
25
27. TYPES OF WIND TUNNEL
TESTING
ForceTest
Force measurement requires a force to be
exerted (lift & drag forces so termed force
test)
The balance can measure only two forces:
lift & drag
27
29. TYPES OF WIND TUNNEL
TESTING
PressureTests
Insert tiny tubes into the model surface or
airstream and connect them to a pressure
measuring device
29
30. PressureTest:
Lowered pressure over the wing surface
reduced the pressure in the manometer
tubes and draws the water level up to a high
level
The lower the pressure, the higher the water
level goes
30
31. TYPES OF WIND TUNNEL
TESTING
Flow Patterns
Allow the streamlines of air flow to look at
the body’s aerodynamic properties
Tufting allows for the flow pattern
visualization
31
40. HOW ARE CARS TESTED IN
WIND TUNNELS??
It is used to quantify and validate what is going
on aerodynamically to the vehicle by
measuring forces exerted on the body through
a 6 component balance.
40
41. HOW ARE CARS TESTED IN
WIND TUNNELS??
Adding a rear wing to your car might gain you
down force, but a wind tunnel will tell you in
fact if it is, how much, and how it affected the
overall front to rear balance of your car.
41
42. HOW ARE CARS TESTED IN
WIND TUNNELS??
Each test will output the drag, down force
(front & rear), and side force (front &
rear), yaw/pitch/roll moments, in order to see
the big picture of what is really happening for
any given configuration.
42
45. COST OF A WIND TUNNEL
A high quality portable vertical wind tunnel
will cost you anywhere from 1.6crores to
4.1crores.This type of tunnel can
accommodate skydivers as well as tourists.
45
46. WIND TUNNELS IN THE
WORLD
1.Altitude IcingWindTunnel(Ontario Canada)
2.Wright BrothersWindTunnel(MIT
Massachusetts USA)
46