Accurate Immersed-Boundary Reconstructions for Viscous Flow Simulations

Immersed-boundary reconstruction schemes for enforcing boundary conditions on surfaces not aligned with grid lines are presented. The flow dynamics in the near-wall regions is fundamental to correctly predict the overall flow, especially in the presence of turbulence. In the current approach, geometrical information and physical conservation constraints are used to build accurate solution reconstructions; in addition, the issue of consistent discretization in the cells crossed by the immersed boundary is treated. A novel interpolation method based on momentum balance and mass conservation based on finite volume method are introduced to correctly predict the velocity and pressure field in the vicinity of the boundaries. The assessment of the solution quality is based on calculations of Taylor decaying vortices. Examples of laminar and turbulent How calculations are also reported.