Hello Everyone ,
I am simulating a 3D airfoil .
The values of Lift coefficients are within the bounds of 10% error compared to the experimental values .
However , the values of drag coefficient I am getting have an error of above 20% compared to experimental values .
I am using SA turbulence model .
If the above discrepancy is due to the wake region/flow separation and wing tip vertices . How can I accurately capture these phenomena ?
A question with poor details!
Tell us about your domain? How big is it? Have you done any mesh sensibility analysis for your domain? SA turbulence model is not too much sensible to the boundary layer mesh but how is your boundary layer mesh? What about y+? did you use any limiter? What' your finite volume method? Cell-centroid or vertox centroid?
If you want to capture the phenamena in the boundary layer, it could be better to use SST k-w turbulence model. Please note that you need to choose different y+ due to the wall function you will consider to use.
Rooholamin Dargahi I have done both the domain and grid sensitivity analysis . My results are domain and mesh independent .
I have taken care of the y+ value too . I have taken the Y+ value of 1 and accordingly kept the first cell height .
I am using least square cell based method .
I have used SST Kw model its results are even bad compared to the SA model .
Re to using SST k-w,
I've not seen your model but have you ploted y+ on your airfoil to make sure y+ is lower than 5?
Is the source of your experimental data valid? from where it has come? do you know how it has measured? Is the model you've sketched influenced by "down-wash effect"?
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