Download - Wind Tunnel Inroduction
-
7/26/2019 Wind Tunnel Inroduction
1/38
Gayon Jio Ross Godfrey S.
Oarde Kevin Victor L.
Zaide John Chester A.
AE 412
6/17/2013
Wind unnel
-
7/26/2019 Wind Tunnel Inroduction
2/38
2/26
Frank Wenham
Benjamin Robins
George Cayley
Osborne Reynolds
Hiram Maxim
Wright Brothers
-
7/26/2019 Wind Tunnel Inroduction
3/38
3/26
Introduction
What is a Wind Tunnel?
AE 412Introduction Classifications Elements Types Shapes Flow Visualization
a facility that provides a controllableflow field for investigating variousflow phenomena and testing
aerodynamic models a tool used in aerodynamic research
to study the effects of air moving pastsolid objects
*** Advantage: experiments can be performed under well-controlledflow circumstances compared to open environment experiments
-
7/26/2019 Wind Tunnel Inroduction
4/38
4/26
National Full-Scale Aerodynamics Complex ,
NASA Ames Research Center, United States
-
7/26/2019 Wind Tunnel Inroduction
5/38
5/26
n Aeronautical Wind Tunnelsn Automobile Tunnels
n Aeroacoustic Tunnels
Classifications of Wind Tunnel
Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
-
7/26/2019 Wind Tunnel Inroduction
6/38
6/26
Aeronautical Wind Tunnels
High Reynolds Number TunnelsPressurized TunnelsHeavy Gas TunnelsCryogenic Tunnels
High-altitude Tunnels
V/STOL TunnelsSpin Tunnels
Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
-
7/26/2019 Wind Tunnel Inroduction
7/387/26
Tunnels are also classified by flow speed:Subsonic (M
-
7/26/2019 Wind Tunnel Inroduction
8/388/26
Wind tunnels may also be classified according to theirair pressure: atmospheric
variable- densityor their size: ordinary full-scale
Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
-
7/26/2019 Wind Tunnel Inroduction
9/389/26
Elements of a Wind Tunnel
Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
-
7/26/2019 Wind Tunnel Inroduction
10/38
10/26
straightens the airflow
*** The less turbulence there is, thebetter the wind tunnel will simulate
actual flying conditions
usually includes a honeycomb flowstraightener and wire mesh
smoothing screens that produce asmooth airflow; effective at reducingswirling currents in the tunnel airflow
Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
-
7/26/2019 Wind Tunnel Inroduction
11/38
11/26
*** purpose: take a large volume of low-velocityair and reduce it to a small volume of high-velocity air
Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
-
7/26/2019 Wind Tunnel Inroduction
12/38
12/26
models of wings or planes are placed here
*** As airflow is brought to thedesired velocity, sensors measure
forces, such as lift and drag, on thetest article.
Lift is the force on the wing opposite the force of gravity.Lift holds a plane in the air.Drag is the force on the wing in the direction of the
airflow. An engine must overcome this force to move aplane through the air.
Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
-
7/26/2019 Wind Tunnel Inroduction
13/38
13/26
Shapes of Test Section
Rectangular (General Purpose)Circular (Axisymmetric Model)Elliptical (Aircraft Model)
AE 412Introduction Classifications Elements Types Shapes Flow Visualization
-
7/26/2019 Wind Tunnel Inroduction
14/38
14/26
-
7/26/2019 Wind Tunnel Inroduction
15/38
15/26
where the air coming out of the test sectionslows down prior to exhausting orrecirculating
a device to lower the air flow speed,
consequently reduce the pressure loss dueto friction
Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
-
7/26/2019 Wind Tunnel Inroduction
16/38
16/26
provides the force that causes air to movethrough the tunnel
*** Fan drive: provide apressure increase offlow, to overcome thepressure loss in the
tunnel circuit.
Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
-
7/26/2019 Wind Tunnel Inroduction
17/38
17/26Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
-
7/26/2019 Wind Tunnel Inroduction
18/38
18/26Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
-
7/26/2019 Wind Tunnel Inroduction
19/38
19/26Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
-
7/26/2019 Wind Tunnel Inroduction
20/38
20/26Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
-
7/26/2019 Wind Tunnel Inroduction
21/38
21/26
Types of Wind Tunnel
Closed-typeOpen-type
Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
Blowdown
Shock Tube
-
7/26/2019 Wind Tunnel Inroduction
22/38
22/26
Open-type Wind Tunnel
also called an Eiffel tunnel
open on both ends and draws airfrom the room into the test section
Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
-
7/26/2019 Wind Tunnel Inroduction
23/38
23/26Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
-
7/26/2019 Wind Tunnel Inroduction
24/38
24/26
Advantages
Low construction cost.Superior design for propulsion and smokevisualization. There is no accumulation of exhaustproducts in an open tunnel
Disadvantages
Poor flow quality possible in the test section
High operating costsNoisy operation
Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
-
7/26/2019 Wind Tunnel Inroduction
25/38
25/26
Closed-type Wind Tunnel
also called an Prandtl tunnel or Gottingen tunnel
*** Air is conducted from the exit of the test sectionback to the fan by series of turning vanes; air isreturned to the contraction section and back to thetest section; air is continuously circulated
Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
-
7/26/2019 Wind Tunnel Inroduction
26/38
26/26Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
-
7/26/2019 Wind Tunnel Inroduction
27/38
27/26Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
-
7/26/2019 Wind Tunnel Inroduction
28/38
28/26Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
-
7/26/2019 Wind Tunnel Inroduction
29/38
29/26
Advantages
Superior flow quality in the test sectionLow operating costsQuiet operation
Disadvantages
Higher construction cost
Inferior design for propulsion and smoke visualizationHotter running conditions than an open return tunnel
Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
-
7/26/2019 Wind Tunnel Inroduction
30/38
30/26
has a high pressure vessel upstream of the testsection and a low pressure reservoir downstreamof the test sectionused for supersonic testing.
Blowdown Wind Tunnel
used for hypersonic testing
Shock Tube
Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
-
7/26/2019 Wind Tunnel Inroduction
31/38
31/26Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
-
7/26/2019 Wind Tunnel Inroduction
32/38
32/26
Advantages
High Mach capability
Lower construction and operating costs.Superior design for propulsion and smoke visualizationSmaller loads on model during startup because of fasterstarts
Disadvantages
Shorter test times require faster (often more expensive)instrumentation.
Need for pressure regulator valves.Noisy operation.
Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
-
7/26/2019 Wind Tunnel Inroduction
33/38
33/26
used to study aerodynamic flow under a widerange of temperatures and pressures that are difficultto obtain in other types of testing facilities;
are also used to investigate compressible flow
phenomena and gas phase combustion reactions
Shock Tube
Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
Fl Vi li ti
-
7/26/2019 Wind Tunnel Inroduction
34/38
34/26
Flow Visualization
aids the people to see the movement of air while
inside the wind tunnel used to make the flow patterns visible
-
7/26/2019 Wind Tunnel Inroduction
35/38
35/26
QualitativeSmokeTuftsEvaporating SuspensionsOil
FogSublimation
Quantitative
Particle Tracking VelocimetryParticle Image VelocimetryLaser Speckle Velocimetry
OpticalShadowgraphSchlieren PhotographyInterferometry
-
7/26/2019 Wind Tunnel Inroduction
36/38
36/26
Shadowgraph-
Schlieren Photography
Inferometry
Optical Methods
-
7/26/2019 Wind Tunnel Inroduction
37/38
37/26
Smoke-
Tufts-
Oil-
Qualitative Methods
Evaporating Suspensions
Fog-
-
7/26/2019 Wind Tunnel Inroduction
38/38
Quantitative Methods
Particle Tracking Velocimetry
Particle Image VelocimetryLaser Speckle Velocimetry