A RESIDUAL ESTIMATOR AS THE ADAPTIVE MESH DRIVER FOR INCOMPRESSIBLE FLOWS

摘要

Numerical simulation of fluid flow inevitably has some error. Indeed, error reduction is crucial in the CFD context. Adaptive mesh refinement (AMR) is a technique for reducing the error by refining the mesh in the regions of dramatically varying physical properties. The error indicator is the component that drives the adaptation process by designating the regions needing refinement. Unfortunately, there is no error indicator which is generally applicable to finite volume simulations of incompressible laminar flows. This paper is an attempt toward establishing a generally applicable error indicator for these simulations. The premise of this paper is that the cell-based residual of the numerical solution is a good candidate for being a general error indicator. First, we develop a method for estimating the residual for incompressible laminar flow simulations. Then, we implement the proposed error indicator in an isotropic adaptation scheme. The results for the lid-driven cavity flow affirms the effectiveness of the method. The error on the adapted mesh proves to be remarkably lower than that of the corresponding uniform mesh with the same number of control volumes. The use of such an error indicator is beneficial, since it is computationally inexpensive and does not require user intervention.