I am trying to set up a small Ahmed Body simulation for use in a derivative work. My first step was to try and match experimental measurements with my model. I have tried multiple configurations (40m/s, 60m/s, 12.5deg, 25deg, 35deg), but my drag values are always much higher than what is reported in literature. For example, my most recent case for a 35deg slant at 40m/s solved to approximately Cd=0.502 which should be approximately 0.250 per Ahmed and multiple other case studies. Below is a link to my project in SimScale:
I have also looked at other work on SimScale regarding the Ahmed body by @jousefm and the nice simulation by @sjoshi. According to the Project Spotlight on the Ahmed Body (Ahmed Body), the drag coefficient was calculated at 0.280 (about 2% error to experiment). When I pull the data results into Paraview though I calculate a Pressure Drag of 0.352 without including the additional Viscous Drag.
Something seems off with all of these results as this should be a fairly simple project overall but the results are not matching with my expectations. Can anyone give me some advice on what I may be doing wrong?