Numerical Investigation Of Transition Predicted And Active Control For Low-speed And Low Reynolds Number Flow

With the understanding of the near space,floating up one aircraft has good prospects,but for one lifter aircraft float,since which the flight environment and limit energy source,requires the aircraft wing and fuselage have large lift,so they want to optimize aerodynamic performance.The aim of aerodynamic designer is always to enhance lift coefficient and reduce drag coefficient.The traditional passive flow control optimization of aerodynamic performance has been difficult to meet the demand for floating up one of the aircraft in this regard.Therefore,in the future the active flow control will assume the task to optimize aerodynamic performance.The research of the jet-based flow control is one of the main studies of active flow control.In this paper,the suction of two-dimensional laminar flow airfoil was studied and compared with the blowing control,combined with the suction control of three-dimensional surface of wing was simulated.This paper mainly study the distribution of the location of the jet hole,pore size,pitch size,jet angle and jet velocity,how to control laminar separation bubble's position and the impact of the law on the airfoil lift-drag ratio.In this paper,we can accurately predict the airfoil surface layer flow separation and transition with SST k-? turbulence model coupled with ?-Re? transition model and supplemented by pre-transition method.The calculation results show that: SST k-? turbulence model coupled ?-Re? transition model can predict airfoil surface laminar separation bubble position;jet can control the development of low Reynolds number laminar flow separation and the effect is good.The jet located rear naked to better suppress laminar separation;and when the angle of suction control is vertical wall,it can significantly improve the low Reynolds number airfoil lift-drag ratio,the effect of flow control is more good.within a certain range when the pumping speed,fixed suction position,greater speed is more able to get better the flow control effect,and on the laminar separation bubble and more effective inhibition.