Numerical Simulation Of Lateral Gaseous Jet In Supersonic Flow

Gaseous lateral jet is widely applied in the control of aircraft. Under realconditions, the jet medium consists of different gases, if the jet problem is studied asthe real condition, the problem would be very complex. Thus, gaseous jet problem isalways simplified as air jet problem. This treatment can simplify the problem but theignorance of jet medium will bring other problems.The changes of the aerodynamic characteristic and flow structure under differentjet medium conditions were studied in this thesis. The gaseous jet simulation platformwhich can simulate two dimensional or three dimensinonal gaseous jet problems, isbased on the air jet simulation software,besides, the development,validation andapplication of the platform were focused on in this thesis.The investigations were conducted by solving the compressible binary-speciesNS equation, the species equation and the transport equation with single gas andmixed gas. Besides, the Runge-Kutta temporal method and2nd order upwind spacialscheme is employed to discretize the governing equations.The turbulence model usedin this thesis is SA turbulence model.The boundary conditions and transportcoefficients were detailedly presented as they are so significant and different from airjet problem. All the detailed developing process are presented in chapter two.The validation mainly consists of air jet simulation and gas jet simulation。Firstly,the missile air injection problem and N2injection problem were simulated by theplatform, through the comparison with each other, the alteration of the platform isproved to be reliable. Then, through the comparision with the experiment and otherreference results, the efficiency of the platform is affirmed. Finally, the gas fractiondistribution proved to be reliable comparing with the simulation results of Fluentsoftware.The application contains two dimensional and three dimensinonal casessimulated by the gaseous jet platform. Firstly, the slot CO2injection and air injectionproblems were respectively simulated under same boundary conditions, by comparingthe results with each other, the differences existing in pressure distribution and flowstructure were achieved. Besides, through comparing the results of platform with theresults of momentum ratio method, the differences between these simulations werealso achieved. Secondly, the comparative results of the slot H2injection and airinjection which were simulated through the same way above, indicates that the gasparameters have some influence on the lateral jet simulation. Thirdly, the influencesbrought by changing the number of slots on the density, pressure, Mach number andgas fraction distribution are huge. Finally, in order to study the influence brought bychanging the specific heat ratio, the missile gaseous jet problems were simulatedunder different specific heat ratio conditions. The results indicate that the specific heatratio of jet medium have little influence on the axial force of the missile but theinfluence on the normal force and pitching moment are great. Besides, the pressurecenter of the missile is changed with the specific heat ratio.At the end of the thesis, the main contents were brifely summarized. the shortages and the future work were also presented.