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Old   March 16, 2006, 13:10
Default Separation of Flow problems
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Simon c
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Hello all, an aerofoil iam looking into is showing some odd results, namely the flow is far to attached to the aerofoil where the flow has slowed. From experience and using xfoil i should expect to see a seperation of the flow. is there any way of forcing fluent to stop being so generous in attaching the flow. Any ideas would be welcome, iam using standard K-e model with Y+ values all between 30-70 and with a very low speed of 15m/s. Yours S
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Old   March 16, 2006, 15:01
Default Re: Separation of Flow problems
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MOHAMMED
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try to increase the velocity to 80 m/s and the angle of attack and see what will happen

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Old   March 16, 2006, 16:16
Default Re: Separation of Flow problems
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Razvan
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The answer to your problem is very simple: switch standard k-e with SST-kw. The underprediction of separated flows is a well known problem of standard k-e turbulence model. Another advice would be to use a y+=1 mesh instead, the results will surely improve.

Razvan

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Old   March 19, 2006, 13:05
Default Re: Separation of Flow problems
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Simon c
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Thanks for the replys. Should have mentioned thats its a car aerofoil so that pressure drag dominates even at 0 angle of attack. Changed the value of length scale within the inlet boundary condition and iam now seeing what i expected. I thought orginally that I should insert a value of L= to my aerofoil length, but using a smaller value I get results I expected. Why is this?? I will have a go with the other turbulence model but my results are good enough now to prove my evaluation of how poor this aerofoil is! Thanks again Yours Simon
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