Boundary condition in fluid-solid interaction.

jinwon park

I am solving an internal explosion in a water-filled cylinder. To reduce computational cost, I asummed axisymmetric flow and am solving half-cylinder section with the aluminum cylinder wall. To impose the fluid loading, the fluid pressure on the interface between the fluid and the solid is imposed on the external loading to the solid, then the interface displacement is given to imply the deformation of fluid domain. Questions are about the B.C in this case. Variables except the velocity are extrapolated from adjacent fluid nodes while velocities are copied from the solid interface. However, it did not perform well. Could anyone advice me how to impose the velocity in the fluid?

Thanks in advance!