I am trying to convert my CFD pressure data to my FEM model. My FEM model is unstructured using FEMAP/UAI NASTRAN and my CFD package is a lower order panel based code. I would like to know how to accurately put my pressures obtained with my CFD code into my FEM grid? My CFD grid is more course than my FEM grid. Any help would be greatly appreciated!

What you need is essentially a projection from your panel mesh (MF) to the structure mesh (MS). I take it you will integrate the pressures on MS to get the nodal forces. There are 2 suggestions I have:

1. When performing the load integrations on MS, project the quadrature points from MS onto MF, then interpolate the values at projected points using conventional finite element shape functions (corresponding to elements/panels of MF).

2. Solve a least squares problem to obtain nodal pressures on MS. This will again require projections similar in nature to step 1.

Hope this helps.