Coupling optimization design of aspirated airfoil with low Reynolds number in high altitude based on CST method

A optimization design method was studied which coupled airfoil with aspirated scheme in the condition of low Reynolds number based on class shape transformation (CST) method. Research results show that: the coupling optimized design can make the total pressure loss reduce by 65%, the static pressure ratio increase by 0.02, and aerodynamic performance gets an obvious enhancement the in the condition of high altitude of 20 km and low Reynolds number. Due to the penalty functions introduced, optimized airfoil aerodynamic performance was also improved in the condition of ground. To aspirate airfoil in the condition of low Reynolds number in high altitude, the design of increasing the load in the front of the aspiration location appropriately, and controlling the boundary layer by aspiration was optimum. And the optimal aspiration location was located in the region of the laminar bubble. Aspiration in the region of the laminar bubble can completely eliminate the laminar separation bubble. And the growth of the displacement thickness and momentum thickness can be inhibited effectively, and the momentum loss within boundary layer can be reduced significantly.