Research On Stage Hot Separation Of Boost Glide Missile And Its Influence At Low Altitude

The trajectory of boost-glide missile is more complex than that of traditional missile,which has directly influence on the stage-separation safety and flight stability.Hot stage separation is an impoartant mode of missile stage separation when the aerodynamic disturbance exists.Hot stage separation under low altitude and high velocity is one of the key problems of boosting phase design of a boost-glide missile.The hot stage separation of the boost-glide missle typifies the intense aerodynamic disturbance,uncertain influence factor and coupled multi physical process.This process and its influence are researched systematically and deeply in this paper.The lateral disturbance characteristic imposed on the missile attitude motion by the complex flow during hot stage separation of the glide-boost missile is studied.As shown by the results,the initial flow field of stage separation can be divided into two parts by the separation gap: internal nozzle jet flow field and external lateral jet interfered flow field.The asymmetric high-pressure regions of flow separation both in internal flow and external flow are the principle sources of missile atttitude disturbance effect.The interference characteristic between the separation gap jet and supersonic incoming flow is studied numerically.The influence by the incoming flow factors,jet flow factors and stage separation motion factors are analyzed.The flow separation and side load characteristics of both conical nozzle and thrust-optimized parabolic nozzle during staging are obtained.The influence by the asymmetric staging motion is investigated.The interval-non-stochastic robustness analysis and design method is studied and applied in the missile control system during stage separation phase.The interval robustness of control system is modeled.The precision of interval robustness indexes of stage separation control system calculated by first order perturbation method,second order perturbation method and sub-interval perturbation method are compared.The optimization model of control system interval robustness is built.The optimization of control system interval robustness of the boost-glide missile is carried out by the sub-interval method and sequence approximate optimization method.The numerical virtual flight technology is studied.A novel framework of numerical virtual flight is proposed in this paper to fully couple the closed-loop controlling 6DOF flight simulation with unsteady numerical simulation of flow field.The numerical virtual flight system is built based on the collaborative simulation of simulation softwares of different disciplines,and applied to simulate stage separation process of a two-stage boost-glide missile with fluid,separation motion and control coupled.This paper provides important basis theory and analysis technology for the design and prediction of the hot stage separation process of the boost-glide missile at low altitude.At the same time,the research fields of lateral jet interfere,nozzle flow separation and side loads,robustness analysis of control system,and numerical virtual flight are explored and in this paper,getting some valuable conclusions.