hemisphere in channel flow

kirill

Hi dear all,

I would like to ask for your ideas:

My problem: I need to model a hemisphere lying on the bottom of the channel with aim to obtain drag and lift coeficients for the Re-number range from 1e+4 to 2e+5. The flow is fully developed, so as inflow boundary condition i give the log velocity profile.

Here it comes: in reality the bottom of the channel is covered with big roughness elements (their size is comparable with the hemisphere size), the hemisphere is lying on the top of them. I give the modified velosity profile as inflow and consider the top of roughness elements as fictive bottom (moving wall boundary condition). Do you think I can get a reasonable estimation of forces acting on the hemisphere and is the bottom boundary condition appropriate?

Thanks a lot for any help

Kirill