Wind tunnel

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Wind tunnel

  1. 1. Gayon, Jio RossGayon, Jio RossGodfrey S.Godfrey S.Oarde, Kevin Victor L.Oarde, Kevin Victor L.Zaide, John Chester A.Zaide, John Chester A.Wind TunnelWind Tunnel
  2. 2. 2/26Frank WenhamFrank WenhamBenjamin RobinsBenjamin RobinsGeorge CayleyGeorge CayleyOsborne ReynoldsOsborne ReynoldsHiram MaximHiram MaximWright BrothersWright Brothers
  3. 3. 3/26IntroductionIntroductionWhat is a Wind Tunnel?AE 412Introduction Classifications Elements Types Shapes Flow Visualization a facility that provides a controllableflow field for investigating various flowphenomena and testing aerodynamicmodels a tool used in aerodynamic researchto study the effects of air moving pastsolid objects*** Advantage: experiments can be performed under well-controlledflow circumstances compared to open environment experiments
  4. 4. 4/26National Full-Scale Aerodynamics Complex ,NASA Ames Research Center, United States
  5. 5. 5/26Aeronautical Wind TunnelsAutomobile TunnelsAeroacoustic TunnelsClassifications of Wind TunnelClassifications of Wind TunnelIntroduction Classifications Elements Types Shapes Flow VisualizationAE 412
  6. 6. 6/26Aeronautical Wind TunnelsAeronautical Wind TunnelsHigh Reynold’s Number TunnelsPressurized TunnelsHeavy Gas TunnelsCryogenic TunnelsHigh-altitude TunnelsV/STOL TunnelsSpin TunnelsIntroduction Classifications Elements Types Shapes Flow VisualizationAE 412
  7. 7. 7/26Tunnels are also classified by flow speed:Subsonic (M<.8),Transonic (.8<M<1.2),Supersonic (1.2<M<5.0), orHypersonic (M>5.0)Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
  8. 8. 8/26Wind tunnels may also be classified according to theirair pressure:atmosphericvariable- densityor their size:ordinaryfull-scaleIntroduction Classifications Elements Types Shapes Flow VisualizationAE 412
  9. 9. 9/26Elements of aElements of aWind TunnelWind TunnelIntroduction Classifications Elements Types Shapes Flow VisualizationAE 412
  10. 10. 10/26 straightens the airflow*** The less turbulence there is, thebetter the wind tunnel will simulateactual flying conditions usually includes a honeycomb flowstraightener and wire meshsmoothing screens that produce asmooth airflow; effective at reducingswirling currents in the tunnel airflowIntroduction Classifications Elements Types Shapes Flow VisualizationAE 412
  11. 11. 11/26*** purpose: take a large volume of low-velocityair and reduce it to a small volume of high-velocity airIntroduction Classifications Elements Types Shapes Flow VisualizationAE 412
  12. 12. 12/26 models of wings or planes are placed here*** As airflow is brought to thedesired velocity, sensors measureforces, 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 theairflow. An engine must overcome this force to move aplane through the air.Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
  13. 13. 13/26Shapes of Test SectionShapes of Test SectionRectangular (General Purpose)Circular (Axisymmetric Model)Elliptical (Aircraft Model)AE 412Introduction Classifications Elements Types Shapes Flow Visualization
  14. 14. 14/26
  15. 15. 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 frictionIntroduction Classifications Elements Types Shapes Flow VisualizationAE 412
  16. 16. 16/26 provides the force that causes air to movethrough the tunnel*** Fan drive: provide apressure increase offlow, to overcome thepressure loss in thetunnel circuit.Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
  17. 17. 17/26Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
  18. 18. 18/26Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
  19. 19. 19/26Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
  20. 20. 20/26Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
  21. 21. 21/26Types of Wind TunnelTypes of Wind TunnelClosed-typeOpen-typeIntroduction Classifications Elements Types Shapes Flow VisualizationAE 412BlowdownShock Tube
  22. 22. 22/26Open-type Wind TunnelOpen-type Wind Tunnel also called an Eiffel tunnel open on both ends and draws airfrom the room into the test sectionIntroduction Classifications Elements Types Shapes Flow VisualizationAE 412
  23. 23. 23/26Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
  24. 24. 24/26AdvantagesAdvantagesLow construction cost.Superior design for propulsion and smokevisualization. There is no accumulation of exhaustproducts in an open tunnelDisadvantagesDisadvantagesPoor flow quality possible in the test sectionHigh operating costsNoisy operationIntroduction Classifications Elements Types Shapes Flow VisualizationAE 412
  25. 25. 25/26Closed-type Wind TunnelClosed-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 circulatedIntroduction Classifications Elements Types Shapes Flow VisualizationAE 412
  26. 26. 26/26Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
  27. 27. 27/26Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
  28. 28. 28/26Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
  29. 29. 29/26AdvantagesAdvantagesSuperior flow quality in the test sectionLow operating costsQuiet operationDisadvantagesDisadvantagesHigher construction costInferior design for propulsion and smoke visualizationHotter running conditions than an open return tunnelIntroduction Classifications Elements Types Shapes Flow VisualizationAE 412
  30. 30. 30/26has a high pressure vessel upstream of the testsection and a low pressure reservoir downstreamof the test sectionused for supersonic testing.Blowdown Wind TunnelBlowdown Wind Tunnelused for hypersonic testingShock TubeShock TubeIntroduction Classifications Elements Types Shapes Flow VisualizationAE 412
  31. 31. 31/26Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
  32. 32. 32/26AdvantagesAdvantagesHigh Mach capabilityLower construction and operating costs.Superior design for propulsion and smoke visualizationSmaller loads on model during startup because of fasterstartsDisadvantagesDisadvantagesShorter test times require faster (often more expensive)instrumentation.Need for pressure regulator valves.Noisy operation.Introduction Classifications Elements Types Shapes Flow VisualizationAE 412
  33. 33. 33/26used 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 flowphenomena and gas phase combustion reactionsShock TubeShock TubeIntroduction Classifications Elements Types Shapes Flow VisualizationAE 412
  34. 34. 34/26Flow VisualizationFlow Visualization aids the people to see the movement of air whileinside the wind tunnel used to make the flow patterns visible
  35. 35. 35/26QualitativeSmokeTuftsEvaporating SuspensionsOilFogSublimationQuantitativeParticle Tracking VelocimetryParticle Image VelocimetryLaser Speckle VelocimetryOpticalShadowgraphSchlieren PhotographyInterferometry
  36. 36. 36/26Shadowgraph-Schlieren PhotographyInferometryOptical MethodsOptical Methods
  37. 37. 37/26Smoke-Tufts-Oil-Qualitative MethodsQualitative MethodsEvaporating SuspensionsFog-
  38. 38. 38/26Quantitative MethodsQuantitative MethodsParticle Tracking VelocimetryParticle Image VelocimetryLaser Speckle Velocimetry

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