An octree-based solution-adaptive Cartesian grid generator and Euler solver for the simulation of three-dimensional inviscid compressible flows

摘要

Cartesian grid generation methods are especially designed algorithms to generate automatic grids for complex geometries and to simulate flows around such geometries regardless of the body shape. Cartesian grids are generated by constructing an octree-based data structure for the purpose of connecting the Cartesian cells to each other. Entire algorithm is implemented in object-oriented FORTRAN programming language. Some special Cartesian algorithms, namely, Ray-Casting method and cut-cell adaptation are used around three-dimensional closed bodies. The flow field around the solid body is obtained by employing Euler equations which are discretised by using finite volume method. Validation of the numerical results is accomplished by comparison with the experimentally obtained data from the flow around ONERA M6 wing. Employing the solution adaptation techniques, pressure coefficients and contours of the flow around the wing have verified and captured two shock waves (weak leading edge shock and midchord shock) by the developed grid-generator-with-eULER-solver-for-3D-applications (GeULER3D) code.