Final Group Design Presentation 03 06 10

Final Group Design Presentation 03 06 10

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  MENG AEROSPACEENGINEERING LAMINAR FLOW CONTROL Supervisor: Dr Jian Wang Mandeep Phull Cecil Ng John Gane 03/06/2010
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  Presentation Content IntroductionWhy?, What?, How? Aims and Objectives Wind Tunnel Turbulence Testing Sphere Test Set up – manufacturing – results Hot wire Test Set up – manufacturing - results Flat & Wavy Surface Models Test Specification Model Specification /21 EGM064: Group Project
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  Introduction What weare doing? Laminar flow control Wind tunnel turbulence level Flat plates Wavy plates /21 EGM064: Group Project
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  Why? Background Laminarflow control Laminar flow Boundary layer forms Smooth flow Transition Point in which laminar flow turns to turbulent Turbulent Contains eddying motions Mechanical energy in flow goes into formation of eddies Higher drag Ref:http://www.aviation-history.com/theory/lam-flow.htm /21 EGM064: Group Project
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  Why? LFC Notnew technology P-51 WWII Natural laminar airfoil section Developed by NASA Outstanding speed and range A lot of research has been carried out Never enough interest Benefits Reduce CO 2 emissions Reduce fuel burn Reduce drag LFC EGM064: Group Project /21
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  What? Aims andobjectives Measure turbulence level of wind tunnel Sphere test Hot-wire Test Carry out transition measurements on flat plate with/without pressure gradient Carry out transition measurements on wavy plate with/without pressure gradient Design and manufacture the sample of flat plate Conduct experiments and numerical simulations on effects of wavy surfaces and flat plates on laminar flow and transition Validate the numerical model /21 EGM064: Group Project
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  How? Methodology Measureturbulence level Turbulent spheres Design bracket to mount spheres to support arm Hot wire test Design bracket to mount probe Design bracket to use in Traverse system Design the flat plate Design the wavy plate Investigate effects of wavy surface on laminar flow and transition experimentally and numerically Computational Fluid Dynamics /21 EGM064: Group Project
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  Wind Tunnel TurbulenceLevel Sphere Test Set up Manufacturing Results Hot Wire Test Set up Manufacturing Results /21 EGM064: Group Project
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  Sphere Test Set-upThere were 3 different sized spheres (6”, 8”, 10”) The spheres were mounted in the wind tunnel attached to a 6 axis balance capable of measuring drag There was no existing method to mount the spheres, so needed to manufacture a support or bracket, making sure the sphere would be mounted parallel to the incoming flow. EGM064: Group Project /21
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  Sphere Test ManufacturingEGM064: Group Project /21 CAD MODEL - BRACKET
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  Sphere Test EGM064:Group Project /21 BRACKET and TEST SET UP
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  Sphere Test -Results EGM064: Group Project /21 Results from Wind Tunnel test
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  Sphere Test -Analysis The average critical Reynolds Number for all spheres was 225,000 for a C D value of 0.3. TF = 385,000/Re c = 1.71 This was Turbulence factor compared to a graph to find intensity. The intensity of the wind tunnel was found to be 0.9% EGM064: Group Project /21
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  Hot Wire TestSet-up The hot wire probe uses a small wire with a current running through it, the rate at which it cools determines the speed of the air flow The hot wire probe and anemometer was provided courtesy of our supervisor The same problems arise of finding a means of mounting it into the flow EGM064: Group Project /21
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  Hot Wire TestManufacturing EGM064: Group Project /21
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  Hot-wire test procedureSetup We used the traverse to map a 7x7 grid of the wind tunnel measuring mean velocity. A velocity profile was built of the working section of the wind tunnel. Turbulence testing was then completed by taking readings in the middle of the test cell at different velocities. EGM064: Group Project /21
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  Hot Wire Test- Results EGM064: Group Project /21 With the hole not covered With the hole covered VELOCITY (m/s) TURBULENCE INTENSITY (%) 10 0.014 15 0.014 20 0.015 25 0.019 30 0.015 VELOCITY (m/s) TURBULENCE INTENSITY (%) 10 0.013 15 0.017 20 0.017 25 0.020 30 0.017
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  Hot Wire Test- Analysis The turbulence level read out by the hot wire is far too low compared to the turbulence spheres. Lack of experience Turbulence sphere test is more likely to be correct. EGM064: Group Project /21
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  Flat Plate DesignThe flat plate will be tested for transition point EGM064: Group Project /21
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  Flat Plate ManufacturingCannot be completed in the Kingston University labs due to machine sizing and tolerances. A quote was given by a specialized engineering company of £2000 (JNDC) for manufacturing. Due to lack of money and facilities for construction the flat plate was not built. EGM064: Group Project /21
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  Conclusions From thefirst wind tunnel test it was concluded that the turbulence level was 0.9%. Following on from this, the second wind tunnel was set up using hot wire anemometer. The turbulence level derived was at 0.02% There is a big discrepancy between the two tests hence requiring further testing. EGM064: Group Project /21
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  THANK YOU FORLISTENING ANY QUESTIONS?