| Box-type launching technology has been gradually adopted by various missile systems because of its advantages such as improving the storage reliability of the missile,easy maintenance,and rapid combat response.The missile's thermal launch process is accompanied by high-pressure,high-speed,high-temperature gas flow and gas-air multiphase flow,with complex flow conditions,which cause severe thermal and dynamic shocks to the launch box,and even lead to launch failure.The in-depth study of the flow characteristics of the gas jet during the thermal launch of the missile,and the analysis of the influence mechanism of the fluid pressure load and temperature load on the launch box are of guiding significance for the thermal launch technology and launch box structure design.Therefore,an enterprise established a school-enterprise cooperation project with Guizhou University to study the impact of the gas jet on the launch box during the missile launch process.In this paper,a certain type of launch box designed by an enterprise is taken as the research object,a 1/4 symmetric model is established,and the coupling between the gas and the launch box during the launch of the missile is studied in depth using theoretical analysis and unidirectional fluid-solid coupling research methods.The main research contents are as follows:(1)Based on the modeling ideas and modeling steps,establish a fluid-structure coupling model of gas and tank during the missile launching process.Block mesh generation technology is used to divide the grid,the boundary of the missile during the launch process is deformed,and domain dynamic layering technology is used to update the grid.(2)Based on fluid dynamics technology,the impact effect of the gas jet on the launch box during the missile launch process is studied,and the non-stationary flow field in the launch box during the thermal launch of the missile is numerically simulated to analyze the launch box when the shock is opened.The flow characteristics of the missile,the flow characteristics inside and outside the launch box when the missile moves,and the impact flow characteristics when the missile flies away from the mouth of the launch box.The research results show that the thermal impact of the gas jet on the inner and outer walls of the launch box is relatively serious.The temperature of the inner and outer walls of the launch box is high.The maximum temperature of the inner box wall is 2920 K and the maximum temperature of the outer box wall is 2850 K.As the missile moves out of the box,the gas The jet has a large dynamic impact on the front end of the launch box.When the distance of the rocket from the nozzle of the launch box is 1m,the impact force of the gas jet on the air surface of the launch box is the largest.(3)Based on the unidirectional fluid-solid coupling,unidirectional thermo-solid coupling,and unidirectional thermo-fluid-solid coupling technologies,the mechanical stress,thermal stress,coupled stress,Distribution rules of mechanical deformation,thermal deformation,and coupling deformation,and the improvement measures of the launch box are proposed according to the coupling analysis results.The research results show that the pressure load and the temperature load have an effect on the structure of the launch box,the mechanical pressure generated by the fluid pressure load has a small effect on the launch box,and the thermal stress generated by the temperature load has a greater impact on the launch box.Under the pressure load,the launch box structure meets the performance and usage requirements;under the temperature load,the launch box produces cracks and plastic deformation;under the simultaneous action of the pressure load and the temperature load,the launch box produces cracks and plastic deformation.The effectiveness of the improvement measures was verified through experiments and applied to production practice. |
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