Research on the Boundary Layer Control of Inner-blown Flaps
A wind tunnel test was made to investigate the aerodynamic characteristics of the airplane with internally blown flaps.The results were obtained according to different jet momentum coefficients and a comparison analysis using CFD technology was made simultaneously.In order to decrease the amount of the grids dramatically,the blowing boundary was set at the nozzle exit instead of the internal of the steady pressure tube and a change of the wind velocity was made to change the jet momentum coefficient.The results obtained by the numerical simulation and the wind tunnel tests were nearly the same,especially in the direction of lift.With large jet momentum,the lift coefficient of CFD results were 5.7%larger than the wind tunnel results,3%for pitching moment.The results also showed that using high speed jet to blow the flap energizes the flow of the boundary layer and prevents the separation of the flap.The blowing jet not only enhanced the negative pressure of the flap,but also increased the negative pressure of the main wing,thus enhancing the lift of the wing simultaneously.Under the large angle of attack,the separation started at the trailing edge of the flap,not the leading edge of the main wing.
NETL
NSTL
万方数据
维普
