A sliding mesh technique for the finite element simulation of fluid–solid interaction problems by using variable-node elements

• We proposed an efficient sliding mesh technique to prevent severe fluid mesh distortion.
• Fluid meshes can slide each other to accommodate a rotational motion of the solid.
• Fluid mesh outside the sliding interface can translate through a background fluid mesh.
• Variable node elements (VNEs) connect non-matching meshes sliding each.
• A fully coupled equation of FSI problems can be solved efficiently in a single computational domain.

A new sliding mesh technique for finite element simulation of fluid–solid interaction problems with large structural motions is presented in this paper. Fluid meshes surrounding a solid can slide each other to accommodate a rotational motion of the solid, and a fluid mesh outside the sliding interface can translate through a background fluid mesh. Because of relative motions of sliding fluid meshes and independently designed fluid and solid meshes, non-matching meshes occur at their common interfaces. The non-matching meshes are connected by using variable-node elements which guarantee the continuity, the compatibility and the force equilibrium across the interfaces.