Deforming Grid Technique Applied to Unsteady Viscous Flow Simulation by a Fully Implicit Solver

摘要

The main objective of the present paper is to document the extension of a grid-movement approach to unsteady viscous flow simulations. The grid-deformation technique based on a modified TFI algorithm is employed to the grid displacements for the oscillating airfoil. This method can be seen as a perturbation method that is independent of the initial grid generation. The present work is intentionally placed into a multiblock framework although only a simple test case is performed. For each moving block, the grid deformation is determined by the TFI perturbations according to the displacement of the block boundaries. The advantages of using interpolated displacements are being fast and simple. Another important feature of the approach is that it allows the overall quality of the initial grid to be maintained. This method provides an efficient way of deforming the grid during an unsteady flow calculation. The current application mainly evaluates the deforming-grid technique for unsteady viscous flow simulation in multiblock grid system. The test results have shown that the deforming-grid technique is very effective and can be employed to the more general motions, for example, deforming airfoils. To demonstrate the performance of this method for the general multiblock case, the next work is to extend it to three-dimensional unsteady viscous flows about a complex multicomponent. configuration. This work is currently underway.