Abstract:For conventional layout civil transport aircraft in a low-speed and high lift configuration, the advance of the stall angle of attack causes the aircraft"s approach speed to be too high. It is necessary to optimize the low-speed characteristics of the high-lift configuration and control the flow separation in the inner wing area of the aircraft wing. The aerodynamic study on the changes in the end face size of the inner slat was carried out through conventional force measurement wind tunnel tests and fluorescent oil flow wind tunnel tests. Under the conditions of the optimal solution, the lift coefficient has been significantly improved, and the pitching moment coefficient still meets the requirements of the classic criterion after aerodynamic optimization, meanwhile, the flow mechanism of flow separation controlled by the extension of the inner slat end face is explained, that is, the airflow passing between the extension part and the main wing can inject high-energy flow into the main wing surface boundary layer near the root of the downstream wing, enhancing the resistance to the ability to withstand adverse pressure gradients and delays local flow separation.
