Tom Allen is one of my colleagues and he sends me here. I will look at John and Bert's work - thank you!nIn the Geometry, I simply dragged and placed a Sphere object and changed the Solid text to Hollow .Has this changed the sphere to a hollpw ball ? nOtherwise,I have read so much on how to create a hollow ball and it seems so hard to create one. By the way, I am using Ansys 2020 R2.nIs there any way I could not use Fluent but physics of rigid objects?.