The simulation of two-dimensional high speed inviscid/viscous reacting flows with real gas effect.

摘要

This dissertation presents a study of hypersonic nonequilibrium flows for partially supporting the aero-optics and aerothermodynamics analysis in the KEW (Kinetic Energy Warhead) endoatmospheric technology program. The analysis is limited to two-dimensional inviscid/viscous hypersonic flows including chemical and thermal nonequilibrium with real-gas effects.; A new computational fluid dynamics code is developed for the study of high speed and high temperature flows. The code employs a semi-implicit, flux splitting, finite-difference scheme based on a total variation diminishing (TVD) algorithm developed by Yee and Shinn, sometimes referred to as the "point implicit TVD MacCormack" scheme, for solving Navier-Stokes equations in generalized coordinates. Finite-rate chemical reactions are fully coupled with the gas dynamical equations. Park's and Dunn/Kang's five- and eleven-species chemistry models for air are used for the present study in aero-optics. The simplified vibrational model is included as well. For viscous calculations, the code utilizes real-gas corrections to viscosity, thermal conductivity and diffusivity.; The hypersonic, endothermic blunt-body reacting flows are selected for the present study to verify the capability of the numerical method, to achieve high resolution in shock layers and to overcome the stiffness in near-equilibrium conditions without resulting in cumbersome calculations. Subsequent work will use these analyses to quantify the effects of thermochemical nonequilibrium on the problem of aero-optics.; The numerical approach demonstrated in current investigation helps to better understand the physics and provide guidelines to further our investigations for a specific aero-optics research.