Aerodynamic Characteristics Analysis Of Distributed Variable Sweep Wing-body Based On CFD

Variable-sweep wing design and optimal variable-sweep law are key point of variable-sweep wing technology, In order to improve its stability and maintain its aerodynamic efficiency at the same time, Designed a distributed variable-sweep wing body model and based on CFD, calculated its aerodynamic characteristics, compare with the aerodynamic characteristics of traditional monolithic sweep-wing body, verified its advantages, then did CFD numerical simulation in broad speed flow field and got calculation results; at last used genetic algorithm to optimize the calculation results in the global scope, got best sweep variation when L/D is maximal, Compare with the other variable-sweep aircraft sweep variation, verified the rationality of the previous variable-sweep law. the specific content are as follows:Firstly, variable-sweep wing body is proposed, on the basis of that overall design requirements and major components(variable-sweep wings) design requirements are further defined, then 3D model of variable-sweep wing body are finished on CATIA platform, including 3 distributed variable-sweep wing body model and 3 monolithic sweep-wing body, parametric model are ready for numerical simulation and aerodynamic simulation.Secondly, GAMBIT is used to do grid breakdown of wing-body model, boundary conditions are set, then numerical simulation was done by FLUENT, calculation results was post processing, compare with two sets of variable-sweep wing body, analysis their lift,resistance and moment characteristics vertically and horizontally.Finally, based on CFD, deeply numerical simulation and aerodynamic simulation was done to distributed variable-sweep wing body model, Numerical methods was used to do post processing, used genetic algorithm to optimize the calculation results in the global scope, best lift to drag ratio was the constraint conditions, then got curve of optimal sweep angle versus Mach, Compared with the other variable-sweep aircraft sweep variation, verified the rationality of the previous variable-sweep law.Study results shows that: compared to the traditional monolithic sweep wing, distributed variable-sweep wing can improve the overall handling stability at the expense of small aerodynamic benefit, which is beneficial to design adaptive elastic variable-sweep wing; aimed at improving the aerodynamic performance of variable-sweep wing aircraft, used genetic algorithm to optimize the calculation results in the global scope, got rational optimal variable-sweep law; when speed increases in the subsonic range, the optimal sweep angle moderate increases reducing induced drag and improve s lift to drag ratio; while in the transonic range, aiming to slow the formation of shock-wave drag, the optimal sweep angle increases rapidly. According to the law of optimal variable-sweep, design the flexible drive mechanism rationally can achieve the goal of design drag-driven variable-sweep wing.