lecture # 3: wind tunnels and water tunnels · 2013. 6. 17. · title: microsoft powerpoint -...

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


Function of Wind Tunnels and Water TunnelsFunction of Wind Tunnels and Water Tunnels

• Producing the desired flow field with controlled conditions


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:


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.


Closed circuit wind tunnelClosed circuit wind tunnel


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


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


Water TunnelsWater Tunnels


Towing TankTowing Tank


Lab#02: Lab#02: Wind Tunnel Wind Tunnel Calibration

Test sectionTest section

Contraction Contraction sectionsection

AAEE

VV

Settling Settling chamberchamber


2

21*

*

VC

qCppp

T

EA

ρ=

=Δ=−



AAEE

VV


Lab#02: Lab#02: Wind Tunnel CalibrationWind Tunnel Calibration


2

21*

*

VC

qCppp

T

EA

ρ=

=Δ=−



AA

EE

VV


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


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.

lecture # 3: wind tunnels and water tunnels · 2013. 6. 17. · title: microsoft powerpoint -...

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