1. Design and Analysis
of Subsonic Wind
Tunnel and Prototype
Generation
Abc name Roll no.123
Def name Roll no.456
Ghi name Roll no.789
Mentor: JKL name

2. Abstract:
• This is a study of very small-scale open-loop wind tunnel design and involves tests
related to it. It will be helpful to explain aerospace engineering fundamentals to pre-
college students
• The designed wind tunnel will be composed by a settling chamber, a contraction
section, a test section, a diffuser as well as a fan.
• We will be measuring flow-field and drag force. Turbulence intensity at different
cross-sections of test chamber will be determined.
• A preliminary test will be on a 3d printed basic shapes and airfoil.
• The result should prove to be compatible with the practical aerodynamic properties
of the body and also follow the same results as some scientific literature. Thus, the
wind tunnel results may be used to calibrate and verify computational fluid
dynamics mathematical models.

3. Content:
• Introduction
• Problem statement
• Aim and objectives
• Classification of Wind Tunnel
• Components of Wind Tunnel
• Manufacturing Procedure
• Software and Hardware Used
• Testing of flow over Airfoil and Other Shapes
• Calculations and Comparison
• Scaling
• Time plan
• Cost
• Limitations and challenges
• Future Work

4. Working On:
1. Wind Tunnel Creation
2. Velocity Profile Generation
3. Lift and Drag coefficient calculation on different bodies
4. Tell at which angle airfoil create the greatest lift

5. Introduction:
The wind tunnel is an aerodynamic device used
to test and analyze the behavior, movement and
flow of air around any engineering object to
facilitate its design process more smoothly and
more comprehensively.

6. Problem
Statement:
• To provide an alternative working
environment for simulations and
get the same results.
• To study aerodynamics in a very
practical way .

7. Aim and Objectives:
Aim:
• Design and manufacture a subsonic wind tunnel to be as a project.
• It helps to do experiments and researches on a small scale and get reliable
results such as lift and drag forces.
Objectives:
• Studying the characteristics of flow in the tunnel.
• Studying the effect of winds in different structures.
• Comparing CFD results to the experimental data from the
prototyped wind tunnel .

8. Classification of Wind Tunnel:
 According to the Velocity
1. Subsonic wind tunnel
2. Supersonic wind tunnel
3. Hypersonic wind tunnel
4. Transonic wind tunnel
 According to the Shape
1. Open circuit wind tunnel
2. Closed circuit wind tunnel

9. Open Circuit
Wind Tunnel
• Air is drawn in from the
laboratory environment,
passes through the test
section and is returned back
to the lab through the tunnel
exhaust.
Fig1. Open circuit wind tunnel

10. Closed Circuit
Wind Tunnel
• Air is conducted from the
exit of the test section back to
the fan by a series of turning
vanes.
• Same air recirculated inside
the wind tunnel.
Fig.2 Closed Circuit wind Tunnel

11. Subsonic
Wind Tunnel
• Low-speed wind tunnels are
used for operations at very
low Mach Number (up to
M=0.4) with speeds in the test
section up to 480 km/h (~ 134
m/s ,M= 0.4)
• Open Circuit and Closed
circuit wind tunnels comes in
its type
Fig.3 Open circuit wind tunnel
Fig.4 Closed circuit wind tunnel

12. Supersonic
Wind Tunnel
• High speed wind tunnels are
used for operations at Mach
Number (0.2<M<5)
• Nozzle geometry determines
Mach number and Reynold
number values
• Needs a drying or a pre-
heating facilities
• A large power demand, so
mostly designed for intermittent
instead of continuous
operation.
Fig.5 Supersonic Wind Tunnel

13. Hypersonic
Wind Tunnel
• High speed wind tunnels
are used for operations at
Mach Number (5<M<15)
Fig.6 Hypersonic Wind Tunnel

14. Transonic
Wind Tunnel
• Wind tunnels are used for
operations at Mach Number
(0.3<M<1.3)
Fig.7 Transonic Wind Tunnel
Fig. 8 Transonic Wind Tunnel

15. Components of Wind Tunnel:
1. Settling Camber
2. Contraction Cone
3. Test Section
4. Diffuser
5. Drive Section
Four main components of
open circuit wind tunnel:
Fig.9 Subsonic Wind Tunnel

16. CAD model of Wind Tunnel :
Fig.10a CAD Model of Subsonic Wind Tunnel using FUSION 360

17. CAD model of Wind Tunnel :
Fig.10b CAD Model of Subsonic Wind Tunnel using FUSION 360

18. Settling Chamber:
The Settling Chamber is at the very front of the wind tunnel, and is made up of
screens and honeycomb-shaped mesh, which straighten out the air and reduce
turbulence
Description Values
Material MDF board
Inlet area 42’’ * 42’’
Outlet area 42’’*42’’
Contraction ratio 1:1
Contraction angle 0
Length 6’’
Fig.11 Settling Chamber

19. Contraction Cone:
The Contraction Cone forces a large volume of air through a
small opening in order to increase the wind velocity in the
tunnel
Fig.12 Contraction Cone
Description Values
Input area of cross-section 42’’*42’’
Output area of cross-section 12’’*12’’
Contraction ratio 12.25
Length 42’’

20. Test Section:
Test Section is the place where a model is mounted on
sensors
Fig.13 Test Section
Description Values
Material used MDF Board
Length 24’’
Input area of cross-section 12’’*12’’
Output area of cross-section 12’’*12’’

21. Diffuser :
The Diffuser is mounted at the end of the Test Section, and keeps
the air running smoothly as it goes toward the back. It also
increases in volume in order to slow the air down as it exits the
tunnel.
Fig.14 Diffuser
Description Values
Input area of cross-section 12’’*12’’
Output area of cross-section 22’’*22’’
Diffuser ratio 3.36
Diffuser length 63’’
Expansion angle 4.54 °

22. Drive Section:
The Drive Section is at the very back of the wind tunnel and it is where the fan is
housed. It will draw air into the wind tunnel by blowing air out of it
Fig.15 Drive Section
FAN Description Values
Input area of cross-section 22’’*22’’
Output area of cross-section 22’’*22’’
Length 6’’
Material Used MDF Board

23. Manufacturing Procedure:
Design and
Calculations of
wind tunnel parts
Design of airfoil
and use CFD
Selection of
materials
Fabrication of
parts
Assembly of parts
Testing of airfoil
with air as
medium
Profile view on
airfoil with smoke
as medium
Reading and
calculations

24. Software and Hardware Used:
Software:
Hardware :
• Mdf board
• Exhaust Fan
• Fog Machine
• Load Cell
• 3D Printed parts
• Fusion 360
• ANSYS 2019 R2

25. Software and Hardware Used:
Fig.1 Mdf board Fig.2 Exhaust fan Fig.3 Fog machine
Fig.4 Load cell Fig.5 3D printed airfoil

26. Basic information about Airfoils:
• An airfoil is the cross-sectional shape of a
wing or blade. 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.
Fig.16 Aeroplane
Fig.17 Flow over airfoil

27. Types and Terminologies of Airfoils:
Types:
1. Symmetrical airfoil: Chord line and camber line coincides.
2. Unsymmetrical airfoil: Chord line and camber line do not
coincides.
Terminologies:
1. Angle of attack(AOA)- The angle measured
between the resultant relative wind and chord
line.
2. Chord line—a straight line intersecting leading
and trailing edges of the airfoil
3. Mean camber line—a line drawn halfway
between the upper and lower surfaces of the
airfoil.
4. Thickness: It is measured perpendicular to the
camber line.
Fig.18 Symmetrical and
Unsymmetrical airfoil
Fig.19 Terminologies of airfoil
Unsymmetrical
Symmetrical

28. Airfoil used for Project:
Airfoil used: NACA0012
Description of NACA0012 Values
Type Symmetrical
Maximum camber 0% at 0% chord
Maximum thickness 12% at 30% chord
Fig.20 Airfoil NACA0012 in Airfoiltools
Fig.21 Airfoil NACA0012 in
Design modular

29. Calculations and Comparison:
Reynolds number calculations:
The Reynolds number is a dimensionless value that measures the ratio of
inertial forces to viscous forces and describes the degree of laminar or
turbulent flow. Systems that operate at the same Reynolds number will
have the same flow characteristics even if the fluid, speed and
characteristic lengths vary.

30. Animation of rotating airfoil: Giving conditions:
Air velocity= 10m/s
Angle of rotation=360degrees

31. Hand written Calculations and Formulas:
Fig.38 Components of Velocity
vector of air striking on Airfoil
Fig.39 Components of Drag
and lift forces

32. Hand written Calculation and Formulas:

36. Prototype Created:
Fig.40 Settling Chamber with Contraction Cone attached Fig.41 Test section

37. Prototype Created:
Fig.42 Assembly 1 Fig.43 Assembly 2

38. Cost:
Sr No. Product Description Cost (INR)
1 MDF Board 2500
2 Load Cells * 2 (5kg each) 600
3 3D Printed Parts 500
4 Straws 300
5 Fan 1000
6 Mountings 200
7 Arduino UNO 500
TOTAL COST 5600

39. Limitations and Challenges:
• Wind Tunnel Covers large area
• Errors in the sensors readings
• Actual results do not match with simulation results
• The results of the simulation programs are inaccurate because they
depend on Density and accuracy of mesh and Computer efficiency ,
CPU time and mesh type
• Corona virus

40. Future Work:
• Ability to control and monitor remotely using the Internet .
• Use of sheet metal
• Control the fan speed to obtain results at different values of air speed.
• Use AC Fan for give a high speeds and PLC and VFD to better control .
• Use more accurate and effective measuring tools.

41. References:
• https://flight.engr.ucdavis.edu/facilities/aeronautical-wind-tunnel/
• https://www.sciencebuddies.org/science-fair-projects/references/how-to-build-a-wind-
tunnel#testing/
• http://www.airfoiltools.com/airfoil/details?airfoil=naca0012h-sa#polars/
• https://www.grc.nasa.gov/WWW/K-12/WindTunnel/wandering_windtunnel.html

42. Thank You