Investigation of micro vortex generators on controlling flow separation over SCCH high-lift configuration

For the problem that the flow separation on the flap lowers the aerodynamic performance of high lift system, an investigation was carried out on using micro vortex generators (VGs) to control the separation on flap of the swept constant chord half-model (SCCH) high-lift configuration, at a small to medium angle of attack, by experimental and numerical methods. The basic flow characteristics of SCCH landing configuration were analyzed by using numerical method to provide required information for the design of micro VGs. Then, by keeping the cruise configuration intact, the preliminary design procedure and design methods of micro VGs were established. In addition, the micro VGs were designed. The effects of VG's arrangement and geometric parameters, such as the arrangement mode, chordwise position, arrangement angle, height and spanwise distance, on controlling efficiency were investigated by using numerical method. Then the parameters of preliminary VGs were adjusted as the basis configuration for wind tunnel test. The experiments were accomplished in NH-2 wind tunnel for validating the numerical method, as well as obtaining the design principles and methods of micro VGs. The parameters of VGs were also optimized based on the experiments. The experimental results showed that the numerical design method can serve as an efficient and accurate design tool. The lift and drag were increased by 10% and 14%, respectively in landing state, which satisfied the requirements for landing. Finally, it was concluded that the established design principles and methods for micro VGs in this investigation can be used in engineering application.