Effect of vortex generator spanwise height distribution pattern on aerodynamic characteristics of a straight wing

Abstract

Vortex generator (VG) is a passive flow control technology, which can effectively inhibit flow separation. Recently, significant research efforts have been devoted to the study on the application of VG in airfoil, wing/blade and aircraft flow separation inhibition. However, the research on the variable height distribution of VG along the wingspan still lacks. This study focuses on the experimental investigation of the influence of variable height distribution of ramp VG on aerodynamic characteristics. First, VG was designed, such that it was composed of two parts, one fixed region and one deformed region, which allowed for height modification. The height of VGs along the wingspan presented equal-height, triangular and trapezoidal distribution, forming a total of 15 VG layouts. Then, the connection mode of the model, the change of angle of attack and the collection and processing of aerodynamic data were introduced. Finally, a wind tunnel experiment was performed to investigate the influence of height distribution of VG on aerodynamic characteristics of wing. The experimental results show that: (1) the height distribution of the three types of VGs could inhibit the stall flow and improve the aerodynamic performance of the wing; (2) “Triangular translation 3” and “Trapezoidal translation 2” were the best layouts, both of which could increase the maximum lift coefficient, delay stall, and significantly increase the lift-to-drag ratio at high angle of attack; (3) the influence of VG height and position factors on wing stall characteristics was analyzed by using the rough set theory, and the key position information of VG arrangement was provided. This study indicates that the variable height distribution is obviously better than the equal height distribution, which can provide ideas and references for the active control of variable height distribution of VGs.