Effects of airfoil geometry on high-speed aerodynamic characteristics of high-pressure capturing wing configuration

The aerodynamic performance of the high-pressure capturing wing (HCW), a novel aerodynamic configuration with significant promise for high-speed aircraft, primarily depends on its geometry and positioning. This configuration differs significantly from conventional ones, as the severe shock wave generated by the airframe strongly interferes with the HCW at high speeds. To investigate the influence of airfoil geometry on the aerodynamic characteristics of this configuration, this study adopts a single-wing HCW concept and selects four typical high-speed airfoils (biconvex, quadrilateral, hexagonal, and triangular) to analyze the effects of airfoil shape on lift-to-drag characteristics and stability under design (freestream Mach number 6) and off-design (freestream Mach number 3) conditions via numerical simulations. The results show that under the design condition, the variation in the overall lift-to-drag ratio caused by different airfoils is relatively small, not exceeding 2.2%, while under the off-design condition it increases to 4.9%. This difference is attributed to the interference of the leading-edge shock wave and reflected shock wave of the capturing wing with the airframe under the off-design condition. Among the four airfoils, the quadrilateral airfoil exhibits the highest overall lift-to-drag ratio under both operating conditions. Stability analysis indicates that, except for the triangular airfoil, for which the center of pressure and the aerodynamic center shift rearward by 3%–4% at most angles of attack, the differences among the other airfoils are small. Therefore, under the design condition and with the same maximum relative thickness, the aerodynamic characteristics of the HCW configuration are not particularly sensitive to the choice of airfoil (except for the stability characteristics of the triangular airfoil), which provides broader optimization space for wide-speed-range airfoil design.