Investigation of Structured and Unstructured Grid Topology and Resolution Dependence for Scale-Resolving Simulations of Axisymmetric Detaching-Reattaching Shear Layers

摘要

The sensitivity to grid changes of a detaching-reattaching shear layer flow over a generic space launch vehicle geometry is investigated with Improved Delayed Detached Eddy Simulation (IDDES). First and second order statistical moments of the flow are compared and show good agreement with experimental and numerical data from literature. A sufficient axial resolution in the initial shear layer region is found to be crucial for an accurate capturing of the spectral content of the flow. Results on a grid with prismatic elements compare well to those on grids with hexahedral elements. A finer circumferential resolution changes the flow field drastically and leads to a merging of the first and second recirculation region, also affecting the pressure field and spectral features. Additionally, an absolute and a directional grid sensors are used that are found to be well suited to support anisotropic grid refinement.