Research On Cold Gas Simulation Rocket Stage Separation Test Technolog

Inter-stage separation is one of the core technologies in the process of solid rocket flight,and ground test is an important means to assess the reliability of inter-stage system separation.The current inter-stage separation test method has the disadvantages of high price,large cost and long cycle time for practical engineering development,and can only be used for system-level performance verification test,not for exploratory development test.Therefore,it is urgent to develop a new type of rocket inter-stage separation test and evaluation system.In this paper,a cold gas simulation rocket separation test method is proposed,which uses the rapid release of high pressure gas from a pressure storage tank to fill the inter-stage section instead of high speed gas,and can assess the kinetic performance of inter-stage separation with low cost and good repeatability.Through theoretical research,simulation calculation and experimental verification,the feasibility and validity of the proposed test technique were verified,filling the gap in the research of inter-stage separation test in domestic and international,and providing a new possibility for the ground test of rocket inter-stage separation ground test.The specific research work is as follows:1.Based on the lumped parameter method and Newton’s second law,a mathematical model of pressure and dynamics is established.The model is used to analyze the law of the change of peak pressure and peak time of the inter-stage separation process affected by various factors(initial pressure of the storage tank,volume of the storage tank,pipe diameter,and volume of the inter-stage section).The results show that the peak pressure increases with the increase of the initial pressure of the storage tank,volume of the storage tank,and pipe area,and decreases with the increase of the volume of the inter-stage section;The theoretical model can accurately describe the cold air simulation rocket inter-stage separation test process,and the pressure build-up speed of inter-stage separation obtained can meet the test requirements.2.The cold air simulation rocket inter-stage separation method is simulated and verified.The dynamic grid technology is used to simulate the flow field structure in the initial pressure holding stage and the whole separation process of the inter-stage separation,and reveal the change law of the flow field structure in the inter-stage section;The influence of the initial pressure of the pressure storage tank,the volume of the pressure storage tank,the area of the pipeline and the volume of the inter-stage on the gas pressure change is analyzed,which provides a reference for the design of the cold gas simulation inter-stage separation test;The feasibility of the simulation model and method is verified by comparing with the calculation results of the mathematical model and the formal test simulation results,which provides a reference for the design of the cold air simulation inter-stage separation test.3.The cold air simulation rocket inter-stage separation test system is designed and tested.The commissioning test results of the pressure-holding process and the separation process are compared with the results of the mathematical model and numerical simulation,respectively,to verify the test method proposed in this paper.The results show that the experimental results are highly consistent with the theoretical calculation results and the numerical simulation results,and can effectively meet the various dynamic evaluation criteria of the inter-stage separation process.