| Hypersonic aircraft are now being designed. For that work to be completed, improved computational tools are required. This work seeks to provide the flow simulation capabilities which are needed. In order to accomplish this, features of several existing codes have been combined and enhanced.;The Compressible Navier-Stokes (CNS) computer code solves the thin-layer Navier-Stokes equations in three dimensions for arbitrary vehicle shapes. The solver can capture strong or weak shocks, and can model separated flow. Boundary-layer turbulence is accounted for empirically by use of the Baldwin-Lomax turbulence model. The code uses ideal gas assumptions or an equilibrium real gas model. Geometries are gridded in a zonal fashion, allowing for flexible convergence strategies and use of the best available equation set for each zone.;The grid on which the computations are performed is critical to the efficient generation of accurate solutions. Some of the criteria for grid quality are discussed, and a simple method of adapting grids to supersonic flow fields is presented.;The code has been tested against analytical, experimental, and numerical results, and shows excellent agreement for critical quantities such as heat transfer and skin friction. The zonal approach of the code and its modular structure allow for future inclusion of internal flow options, more complex geometrical models, nonequilibrium air chemistry, combustion chemistry, and other improvements. |
