Modeling And Applications Of Dynamic Characteristics In Combustion System Of Hypersonic High Temperature Tunnel

Combustion-heated hypersonic high-temperature tunnel is the main equipment of hypersonic propulsion,aerodynamic characteristics/propulsion integrative hypersonic flight vehicle,as well as thermal-structure test.Once combustion-heated system,as the core subsystem,has problems of systematic dynamics such as low-frequency oscillation combustion or overshoot,it will affect the performance as well as the safe and normal operation of the tunnels.This will be one of the technical difficulties and risks of the development of the tunnels.The largest Combustion-heated hypersonic high-temperature tunnel in the world has being developed in CARDC.To reduce risks,it is necessary to study on dynamic characteristics of combustion-heated system.Considering the combination and operating feature of combustion system,the thesis develops dynamics modeling for components with dynamic characteristics based on the dynamics theories and research results of liquid rocket engine.A simulation tool is developed and verified by analytical and experimental results.The thesis also performs applied research on typical engineering problems.The main task includes:(1)Developing dynamics model suitable to combustion-heated system.The components compose of normal temperature liquid/air pipeline model,low temperature pipeline model,branch and vessel model,valve and pore plate model,oxygen/air blender model,venturi model,injector model,combustor model,nozzle model as well as filling and blow model.(2)Contrasting and testing the calculation methods and models based on the shock tube Riemann problem and pipeline filling water hammer problem and explores the feasibility of modularize simulation.It is found out that the distribution of density,velocity,pressure and temperature in shock tube calculation is well consistent with analytical solution and precisely catches shocks and contact discontinuity.In the problem of pipeline filling water hammer,the calculated pressure-time lines are well correspond to test results.The results show that block simulation can be realized when combined with Simulink S-function,which can be applied in engineering.(3)Developing simulating analysis of three typical engineering problems,namely dynamic responding characteristics of press-leading tube and cold state adjusting and burning state starting of combustion system.The thesis also develops parts of contrasting tests.The results show that simulating tools based on Simulink environment can reliably realize dynamic characteristic simulation of a number of systems with complicated components,and helps to optimize the design and debugging of combustion system.