lecture # 3: wind tunnels and water tunnels · 2013. 6. 17. · title: microsoft powerpoint -...
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Copyright Copyright ©© by Dr. Hui Hu @ Iowa State University. All Rights Reserved!by Dr. Hui Hu @ Iowa State University. All Rights Reserved!
Dr. HDr. Hui Huui Hu
Department of Aerospace EngineeringDepartment of Aerospace EngineeringIowa State University Iowa State University
Ames, Iowa 50011, U.S.AAmes, Iowa 50011, U.S.A
Lecture # 3: Lecture # 3: Wind Tunnels and Water TunnelsWind Tunnels and Water Tunnels
AerEAerE 334444 -- Lecture NotesLecture Notes
Copyright Copyright ©© by Dr. Hui Hu @ Iowa State University. All Rights Reserved!by Dr. Hui Hu @ Iowa State University. All Rights Reserved!
Function of Wind Tunnels and Water TunnelsFunction of Wind Tunnels and Water Tunnels
• Producing the desired flow field with controlled conditions
Copyright Copyright ©© by Dr. Hui Hu @ Iowa State University. All Rights Reserved!by Dr. Hui Hu @ Iowa State University. All Rights Reserved!
Types of Wind TunnelsTypes of Wind Tunnels
Based on Flow Speed:Based on Flow Speed:•• Subsonic or low speed wind tunnels (M<<1.0)Subsonic or low speed wind tunnels (M<<1.0)•• Transonic wind tunnels (MTransonic wind tunnels (M≈≈1.0)1.0)•• Supersonic wing tunnels (1.0 <M<5.0)Supersonic wing tunnels (1.0 <M<5.0)•• Hypersonic wind tunnels (M>5.0) Hypersonic wind tunnels (M>5.0)
Based on Shape:• Open circuit wind tunnel: • Closed circuit wind tunnel:
Copyright Copyright ©© by Dr. Hui Hu @ Iowa State University. All Rights Reserved!by Dr. Hui Hu @ Iowa State University. All Rights Reserved!
Open Circuit Wind Tunnel
•• Suction wind tunnel:Suction wind tunnel: With the inlet open to atmosphere, axial fan or With the inlet open to atmosphere, axial fan or centrifugal blower is installed after test section. centrifugal blower is installed after test section.
•• Blow down wind tunnel:Blow down wind tunnel: A blower is installed at the inlet of wind tunnel A blower is installed at the inlet of wind tunnel which throws the air into wind tunnel. which throws the air into wind tunnel.
Copyright Copyright ©© by Dr. Hui Hu @ Iowa State University. All Rights Reserved!by Dr. Hui Hu @ Iowa State University. All Rights Reserved!
Closed circuit wind tunnelClosed circuit wind tunnel
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Components of a Wind TunnelComponents of a Wind Tunnel•• Test section Test section •• Contraction sectionContraction section•• Diffuser sectionDiffuser section•• Setting chamberSetting chamber•• Screens and similar structuresScreens and similar structures•• Cooling system / radiatorsCooling system / radiators•• Motors /fans Motors /fans
Copyright Copyright ©© by Dr. Hui Hu @ Iowa State University. All Rights Reserved!by Dr. Hui Hu @ Iowa State University. All Rights Reserved!
Function of Contraction
A1
V1
ΔV1ΔV2
V2
A2
10%
2
11 A
Ac = 001.0100
1.01
1
12
2
2 ==Δ
=Δ
VV
cVV
1.01
1 =ΔVVif
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Water TunnelsWater Tunnels
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Towing TankTowing Tank
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Lab#02: Lab#02: Wind Tunnel Wind Tunnel Calibration
Test sectionTest section
Contraction Contraction sectionsection
AAEE
VV
Settling Settling chamberchamber
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2
21*
*
VC
qCppp
T
EA
ρ=
=Δ=−
Test sectionTest section
Contraction Contraction sectionsection
AAEE
VV
Settling Settling chamberchamber
Lab#02: Lab#02: Wind Tunnel CalibrationWind Tunnel Calibration
Copyright Copyright ©© by Dr. Hui Hu @ Iowa State University. All Rights Reserved!by Dr. Hui Hu @ Iowa State University. All Rights Reserved!
2
21*
*
VC
qCppp
T
EA
ρ=
=Δ=−
Test sectionTest section
Contraction Contraction sectionsection
AA
EE
VV
Settling Settling chamberchamber
0
20
40
60
80
100
120
140
0 20 40 60 80 100 120 140
Linear curve fittingExperimental data
ΔP = PA-PE (Pa)
q =0
.5*ρ
V2
Lab#02: Lab#02: Wind Tunnel CalibrationWind Tunnel Calibration
Copyright Copyright ©© by Dr. Hui Hu @ Iowa State University. All Rights Reserved!by Dr. Hui Hu @ Iowa State University. All Rights Reserved!
Before you do the LabsBefore you do the Labs……
•• Choose 1~2 member as the Lead OperatorsChoose 1~2 member as the Lead Operators
•• Bring you own flash drive for the data storage.Bring you own flash drive for the data storage.
•• Do not touch other research equipments in the wind Do not touch other research equipments in the wind tunnel laboratory.tunnel laboratory.
•• Keep the wind tunnel laboratory clean and organized.Keep the wind tunnel laboratory clean and organized.