The Calculation Of Basic Flow Of Hypersonic Flat-plate Boundary Layer With The Real Gas Effects

Significant high temperature will appear on aircrafts in hypersonic flight, which isbecause of the effect from shock compression and viscous friction. With thetemperature growing high, the internal vibrational degrees of freedom in themolecules are excitation, and then dissociation, ionization chemical reaction exists,which, in a whole, form the “real gas effects”. Analysis of the “real gas effects” onfluid field and accurate computation of the aerodynamic force and heating is ofimportant significance for aircraft design; On the other hand, these features also havegreat effects on the accuracy of the transition prediction. So, it is necessary to developthis research which concerns the “real gas effects” on the computation of hypersonicbasic flow under particular high temperature.In this paper, the “real gas effects” was considered in a hypersonic flat-plateboundary layer, and the research was focused on the thermochemical equilibrium flow.Three kinds of methods (forward solver, similarity solution, direct numericalsimulation) were used in this paper to obtain the basic flow. Conclusions of thecomputation are as follows:1. The real gas does not obey the perfect gas model at all. Obvious differences areobserved in the velocity and temperature profiles compared to perfect gas onesunder hypersonic basic flow.2. When considering the “real gas effects”, the thickness of the boundary layerbecomes thinner, and the temperature in the boundary layer becomes lower thanthose use perfect gas model.3. Similar solution of thermochemical equilibrium flow is presence in the flat-plateboundary layer. More satisfied solution of the forward solver may obtain, if theinitial profile is given as good as possible.