Lecture # 3: Wind Tunnels and Water Tunnels · Cavitating propeller in a water tunnel experiment at...
Transcript of Lecture # 3: Wind Tunnels and Water Tunnels · Cavitating propeller in a water tunnel experiment at...
Copyright © by Dr. Hui Hu @ Iowa State University. All Rights Reserved!
Dr. Hui Hu
Department of Aerospace Engineering
Iowa State University
Ames, Iowa 50011, U.S.A
Lecture # 3: Wind Tunnels and Water Tunnels
AerE 344 - Lecture Notes
Copyright © by Dr. Hui Hu @ Iowa State University. All Rights Reserved!
Function of Wind Tunnels and Water Tunnels
• Producing the desired flow field with controlled conditions
Copyright © by Dr. Hui Hu @ Iowa State University. All Rights Reserved!
Types of Wind Tunnels
Based on Flow Speed:
• Subsonic or low speed wind tunnels (M<<1.0)
• Transonic wind tunnels (M1.0)
• Supersonic wing tunnels (1.0 <M<5.0)
• Hypersonic wind tunnels (M>5.0)
Based on Shape:
• Open circuit wind tunnel:
• Closed circuit wind tunnel:
Copyright © by Dr. Hui Hu @ Iowa State University. All Rights Reserved!
Open Circuit Wind Tunnel
• Suction wind tunnel: With the inlet open to atmosphere, axial fan or
centrifugal blower is installed after test section.
• Blow down wind tunnel: A blower is installed at the inlet of wind tunnel
which throws the air into wind tunnel.
Copyright © by Dr. Hui Hu @ Iowa State University. All Rights Reserved!
Components of a Wind Tunnel
• Test section
• Contraction section
• Diffuser section
• Setting chamber
• Screens and similar structures
• Cooling system / radiators
• Motors /fans
Copyright © by Dr. Hui Hu @ Iowa State University. All Rights Reserved!
Function of Contraction
A1
V1
ΔV1ΔV2
V2
A2
10%
2
11
A
Ac 001.0
100
1.01
1
1
2
2
2
V
V
cV
V1.0
1
1
V
Vif
Copyright © by Dr. Hui Hu @ Iowa State University. All Rights Reserved!
NASA Ames Wind Tunnel
(24.4m× 36.6m test section, 75GW power)
Copyright © by Dr. Hui Hu @ Iowa State University. All Rights Reserved!
Lab#02: Wind Tunnel Calibration
Test section
Contraction
section
A
E
V
Settling
chamber
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2
2
1*
*
VC
qC
ppp
T
EA
Test section
Contraction
section
A
E
V
Settling
chamber
Lab#02: Wind Tunnel Calibration
Copyright © by Dr. Hui Hu @ Iowa State University. All Rights Reserved!
2
2
1*
*
VC
qC
ppp
T
EA
Test section
Contraction
section
A
E
V
Settling
chamber
0
20
40
60
80
100
120
140
0 20 40 60 80 100 120 140
Linear curve fittingExperimental data
P = PA-P
E (Pa)
q =
0.5
*V
2
Lab#02: Wind Tunnel Calibration
Copyright © by Dr. Hui Hu @ Iowa State University. All Rights Reserved!
Before you do the Labs…
• Choose 1~2 member as the Lead Operators
• Bring you own flash drive for the data storage.
• Do not touch other research equipments in the wind tunnel laboratory.
• Keep the wind tunnel laboratory clean and organized.