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: Lecture # 3: Lecture # 3: Lecture # 3: Wind Tunnels and Water TunnelsWind Tunnels and Water TunnelsWind Tunnels and Water TunnelsWind Tunnels and Water Tunnels
AerE 545 - Lecture Notes
Copyright © by Dr. Hui Hu @ Iowa State University. All Rights Reserved!
Function of Wind Tunnels and Water TunnelsFunction of Wind Tunnels and Water TunnelsFunction of Wind Tunnels and Water TunnelsFunction 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 TunnelsTypes of Wind TunnelsTypes of Wind TunnelsTypes of Wind Tunnels
Based on Flow Speed:
• Subsonic or low speed wind tunnels (M<<1.0)
• Transonic wind tunnels (M≈≈≈≈1.0)
• 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 TunnelOpen Circuit Wind TunnelOpen Circuit Wind TunnelOpen 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!
Closed circuit wind tunnelClosed circuit wind tunnelClosed circuit wind tunnelClosed circuit wind tunnel
Copyright © by Dr. Hui Hu @ Iowa State University. All Rights Reserved!
Components of a Wind TunnelComponents of a Wind TunnelComponents of a Wind TunnelComponents 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
∆V1
∆V2
V2
A2
10%
2
1
1
A
Ac = 001.0
100
1.01
1
1
2
2
2==
∆=
∆
V
V
cV
V1.0
1
1=
∆
V
Vif
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Icing Wind TunnelsIcing Wind TunnelsIcing Wind TunnelsIcing Wind Tunnels
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Water TunnelsWater TunnelsWater TunnelsWater Tunnels
Copyright © by Dr. Hui Hu @ Iowa State University. All Rights Reserved!
Towing TankTowing TankTowing TankTowing Tank
