Novel Finite‐Volume Complete Flux Approximation Schemes for the Incompressible Navier–Stokes Equations

Abstract

We construct novel flux approximation schemes for the semidiscretized incompressible Navier–Stokes equations by finite‐volume method on a staggered mesh. The calculation of the cell‐face fluxes has been done by solving appropriate local non‐linear boundary value problems (BVP). Consequently, the cell‐face fluxes are represented as the sum of a homogeneous and an inhomogeneous flux; the homogeneous part represents the contribution of convection and viscous‐friction, while the inhomogeneous part represents the contribution of the source terms. We derive three flux approximation schemes to include the impact of the source terms on the numerical fluxes. The first one is based on a homogeneous 1‐D local BVP without source. The second scheme is based on an inhomogeneous 1‐D local BVP considering only the pressure gradient term in the source. Finally, a complete flux scheme is derived which is based on an inhomogeneous 2‐D local BVP. It takes into account both the gradient of the cross‐flux and the pressure gradient in the source term. The numerical validation of the schemes is done for the benchmark lid‐driven cavity flow for considerably high numbers along with a numerical convergence test for the exact solution of the Taylor–Green vortex problem.