Validation of 2D CFD model with 3D wind tunnel Data
 

Hello,
I completed a 2D bluff body turbulent model in Ansys Fluent. I am getting a satisfactory drag coefficient and Strouhal's number. However, when I am trying to validate my results with the 3D wind tunnel data for the fluctuating drag and lift, I have a problem. The 2D wind tunnel data is comparatively very high for the RMS and the peak.
So, my question is,
Can we validate 2D CFD data with 3D wind tunnel data? Or we have to make a 3D model for the comparison?
I hope you can help in this regard. Thank You in advance.
With best regards,
Saugat

2D Planar
 

You mentioned that the drag coefficient and Strouhal number are satisfactory. Since you also mention that the drag and lift are not matching with the wind tunnel data, could you explain in what sense are they satisfactory; are those values stable and numerically converged or are those matching with some other results?

You can compare 2D with 3D provided the assumptions in the 2D are valid for the 3D model it represents. A 3D model is 3D if it has three-dimensional effects taken into account. E.g., when airfoil profiles are tested in a wind-tunnel then their width is kept rather large as compared to chord length to avoid 3D effects. However, if the wind tunnel data are for 3D, then the results should match only for the boundaries normal to the axes involved in the simulation and not for the whole model. Even for the normal boundaries results would match if the variation across the third dimension is insignificant, which it never is if the wind tunnel model is 3D in the sense explained above.