Hello, I have been trying to simulate air flow around a floorball (a ball with 26 1cm wide holes on it) and a smooth sphere, and to compare their drag coefficients at different Re.
My problem is mainly with the accuracy of the results from the smooth sphere, its Cd being at about half of the expected result. At around Re 0.95e5 its 0.26 while the expected Cd would be near 0.5. At the same Re the floorball has Cd of 0.55, much closer, but still not quite. The trend of smooth sphere having Cd half of the floorball seems to continue at other Re, with Cd increasing at lower Re but difference staying same.
Both simulations have exactly the same quality meshes and simulation setup, but the results are very different. The results don´t need to match real life values exactly, but rather be comparable with each other. There is probably something wrong with my simulation setup, so feel free check the project out.
I am quite new to CFD and SimScale, so any help would be appreciated.