Hypersonic Vehicle Investigations at High Altitudes, Enhancement of Aerodynamic Efficiency

In this work, the problem of designing a hypersonic vehicle with high lift-drag ratio in hypersonic rarefied regimes is investigated. At high altitudes, the assumption of continuity employed in the Navier Stocks equations is no longer true and is not possible to simulate the problem with conventional CFD routines. The Direct Simulation of Monte Carlo (DSMC) which is a particle-based method was employed to simulate the hypersonic rarefied regimes of hypersonic vehicles. In the first step, based on momentum theory, a simple definition for increasing aerodynamic efficiency was provided. According to this definition, a two-dimensional body under considerations of hypersonic-rarefied flow regimes was analyzed using the DSMC code of DS2V. According to the facts obtained from this analysis, we considered a typical three-dimensional body, and developed the configurations of high aerodynamic efficiencies. The simulations were conducted in three-dimensional space by the DSMC program of DS3V showed that the abovementioned definition is applicable to three-dimensional geometries. Finally, based on authenticated definitions, we exemplified a three-dimensional body, which is capable to produce high aerodynamic efficiencies in hypersonic regimes at high altitudes.