Numerical Study of the High Speed Main Flow and Thrust Vectoring Interaction
|School||China Aerodynamics Research and Development Center|
|Keywords||Thrust vectoring Cascade Thrust vector Mach number Flow around Flight angle of attack Supersonic mainstream Numerical Simulation Study Wake flow Nozzle throat High angle of attack maneuver Aerodynamic characteristics Control surfaces Axisymmetric vectoring nozzle Interference effects Low-speed airfoils Shock wave Hybrid model The structure of the flow field Wall pressure|
The next-generation fighter requirement has good maneuverability and STOL performance. During high angle of attack maneuvers, the aircraft around the complex flow phenomena, serious flow separation, vertical tail control surfaces immersed in the wake flow, and control surface efficiency is drastically reduced or even complete failure to obtain the necessary control and control surface deflection torque method, has been difficult to meet the requirements of the high angle of attack maneuver, must thrust vector control technology. A key technology thrust vectoring technology as the fourth-generation fighter design from the eighties of the last century, the United States has carried out extensive research, including theoretical and computational analysis, scale model tests, flight simulator simulation and flight demonstration verification, and other means, and has been successfully applied to the F-22, F-35 fourth-generation main fighter plane. Mainstream thrust vector jet stream interference effect is a major aspect of the thrust vectoring technology. It is worth noting that the thrust vectoring tail jet interaction effects with traditional nozzle interference effect is quite different, the traditional nozzle interference effect is a weak disturbance jet interaction effects and thrust vectoring tail is a strong disturbance , and is strongly dependent on the airframe / propulsion system integration design. Obviously, to study law and mechanism of the interference effects of jet tail the mainstream and thrust vector will be to optimize the integrated design of airframe / propulsion system based on clear background. In this paper, the numerical simulation and numerical study of a simplified model of the aircraft, the interference effect of thrust vectoring tail jet and high-speed mainstream summarizes stream Mach number, angle of attack, the nozzle deflection angle, jet Mach number, The total pressure of the jet, the jet total temperature parameters on the aerodynamic characteristics of the aircraft, and analyzed the flow mechanism to provide some guidance for the follow-up test research. The paper is divided into five chapters: Chapter One is the introduction, discusses the thrust vector technology background, thrust vectoring technology at home and abroad and research progress, the clear thrust vector jet with mainstream interference effects of significance. Second chapter is a numerical method, this study uses the control equation, the the space discrete format, and time marching method, boundary conditions and turbulence simulation method, especially details of an autonomous development of hybrid RANS turbulence scales / LES hybrid model and its improvement. Chapter example verification, improved RANS / LES hybrid model and calculation software FLY3D assessment validation through a series of typical examples, including the transonic airfoil viscous flow, low-speed airfoil flow around a high angle of attack, low-speed The flow around a cylinder and the bottom of the supersonic cylindrical flow around a given experiment more consistent or close to the results, verify the improved RANS / LES hybrid model and calculation software FLY3D applicability. Chapter IV is to simplify the the fighter model thrust vectoring jet with high-speed mainstream interference effects, the computing model, computational grids and specific boundary conditions, the system studied stream Mach number, angle of attack, the nozzle deflection angle and jet Mach number, total pressure jet, jet total temperature and other parameters on the aerodynamic characteristics of the aircraft law, the results showed that: the simplified fighter model thrust vectoring tail jet interference for high-speed mainstream confined to the tail of the local area, the whole machine pneumatic characteristics of smaller, only have a larger angle of attack must embody; However, the high-speed mainstream tail jet interference significantly, the loss of thrust vector angle with the free stream Mach number and angle of attack increases. The fifth chapter is the conclusion, summarizes the research work, the need to further deepen the research direction and prospects. Finally, Acknowledgements and References.