The numerical study of 3-dimensional laminar hypersonic blunt-fin interactions

摘要

The three-dimensional numerical simulation of a Mach 6.7 perfect gas, with a unit Reynolds number of 7.6 x 106m-1, over several configurations of a blunt-fin attached to a flat plate are carried out. The resulting interference flowfield is reported in this thesis.The laminar Navier-Stokes code developed by Narvarro-Martinez [47] has been modified to solve any general three-dimensional problem, and the complete Navier-Stokes equations. The numerical scheme is operator split, allowing independent numerical schemes to be used on each of the individual contributions to the Navier-Stokes, which can be combined later to advance the entire solution in time. The inviscid part uses a first order Godunov method with a HLLC approximate Riemann solver; second order accuracy is achieved through the MUSCL approach. The viscous contribution is modeled by a centered difference scheme. An iterative matrix solver is used to advance the implicit solution in time. To handle large three-dimensional grids, the code is implicit and run on a parallel computer cluster. The three-dimensional results from the various blunt-fins simulated show a complex rich three-dimensional structure, with several horseshoe vortices formed within the separated flow. Extremely large heat transfer rates have been measured along the path of these vortices on the plate surface, and on the leading edge of the unswept blunt-fin. In particular cases heat transfer rates as high as (h/hu)?60 were measured for the 5mm diameter fin. The 5mm fin results show remarkable similarity to the experimental results obtained by Schuricht [53]. The results obtained using a swept fin, and a fin of doubled fin diameter also show good agreement with the trends observed by Schuricht and others for a laminar interaction.