The Unsteady Numerical Simulation Research On The Stage Separation Of Hypersonic Vehicle

The paper conducts the stage separation problems of hypersonic vehicles as theresearch object. CFD unsteady numerical simulation is taken as the main means of theresearch, two kinds of numerical methods of the multi-body relative motion problem areused flexibly, which are the structured chimera grid technology and non-structuralDescartes grid technology coupled with Euler equation and6-Dof equation.The accuracy and feasibility of the calculation results from the non-structuralCartesian grid technology coupled the Euler equation and6Dof movement equation areverified, as well as the the structured chimera grid technology.Firstly, the stage separation analysis models of the hypersonic vehicle are built,including two-dimensional approximate HyFly model, three-dimensional axisymmetricmodel, the waverider-based precursor model based on the grid fin. With the highaccuracy of unsteady numerical simulation, the separation process of2-D HyFly modelis simulated accurately, revealling the mutual interference between the two-bodyseparation process which brings the unsteady flow field characteristics.Secondly, in the unsteady separation process, in order to examine thecharacteristics of the interference between the two bodies, the paper takes the angles ofattack when separation begins, the initial relatively separation velocity of the separationinto consideration.The flow field of the hypersonic vehicle is complex enough with the interstagesegment due to the two-body mutual aerodynamic interference. So the unsteadyaerodynamic analysis of the separation process has great importantance.In order to improve the aerodynamic characteristics of the booster stage so as toimprove the the longitudinal aerodynamic characteristics of the entire hypersoniccombination vehicle, this paper introduces the application of grid fin, which is a keyissue in this study and shows excellent performance.At last, this paper makes use of the fast, efficient, and credible non-structuralCartesian grid technology to get unsteady aerodynamic characteristics of themulti-separation problem, which shows great potential.