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how to set turbulence model and inflation layers in analysis of an aircraft

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Old   April 22, 2013, 15:06
Unhappy how to set turbulence model and inflation layers in analysis of an aircraft
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santosh kumar
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i am mechanical engineering student and i am doing a cdf modelling of v22 osprey,US tilt rotor aircraft as a part of my college project.Although we donno the exact wing profile of the plane we are focussing on the methods of cfd modelling therefore we are using a naca 63(3)-418 profile.The other dimensions of the model were taken from wikipage and decent model of plane was made.It is 1/147th scaled model and we are analysing it using ansys14 academic licensed version.The problems we are facing are:
1)i think that the cl of the aircraft after analysis should be around .4 since the airfoil design cl is .4 am i right in thinking so? and the cd should be of order 10^-2(for any aircraft that is usual cd range).But my results are cl=.17 and cd is of order 10^-1.
2)my y+ values range from almost 1 to 92.I tried using k epsilon realizable, then after going through some cfd blogsI changed the model to spalart almacus 1 eqn model and increased the inflation layers to 15.Although i got slight improvement. i still think results are not right.Can anyone tell me which changes could probably bring better results?Quick help would be highly appreciated.Thanks in advance
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Old   April 24, 2013, 15:26
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Sijal Ahmed Memon (turboenginner@gmail.com)
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You should be able to get the accurate Cl but drag is tricky to get accurate. You should check your refernce values.
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Old   April 24, 2013, 20:26
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thanku FAR for ur reply.finally someone replied! my reference values are that of area of wing for my scaled wing
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