Reynolds Averaged Navier-Stokes Analysis for Civil Transport Aircraft using Structured and Unstructured grids

The current study deals with the two different mesh generation strategies demonstrated for the RANS simulations over a typical civil transport aircraft near transonic regime. The commercial grid generator ICEM-CFD is used for meshing and High Resolution Flow Solver on Unstructured Meshes (HiFUN)[Ref.1] is used as a solver for the numerical computations. The accurate prediction of aerodynamic coefficients is an important design parameter in preliminary design phase of civil transport aircraft. The hybrid tetrahedral & prismatic unstructured mesh and mapped hexahedral mesh are generated. In the absence of experimental results, the simulated results are compared with the CFD (RANS) data available from Computational Research Laboratories (CRL)[Ref.2] , Pune. It is reported in the literature that any grid used for computing in such flow regime should not only be fine near the body but also in the region sufficiently away from the body in order to capture the shock strength precisely. An attempt has been made to satisfy the aforementioned criteria by placing a far-field boundary condition sufficiently away (typically about hundreds chords) from the body. The results presented in the paper thoroughly demonstrate the unstructured grid methodology developed with minimal number of cells that matches reasonably well between twice the number of in-housed generated mapped hexahedral cells and CRL unstructured mesh