Research Centre for Modelling and Simulation, National University of Sciences and Technology, Pakistan
Aerospace Engineering Department, College of Aeronautical Engineering, National University of Sciences and Technology, Pakistan
Delayed stall is the most dominant lift enhancing factor in insect flapping motion. Micro air vehicle operates at Reynolds number 104-105; slightly higher than the insects’ Reynolds number (Re). In the present research, thefocus is to investigate “stall-absent” phenomenon at Re representative of the micro air vehicles, the effect of spanwiseflow on the leading edge vortex and also to study the effect of geometry variations on the aerodynamic performance of the wing in unsteady motion. Corrugated dragonfly airfoil with rectangular wing planform is used, however, with wing kinematics restricted to azimuth rotation only. Three-dimensionalfinite-volume method is used, through commercial software Fluent, to numerically solve time-dependent incompressible Navier-Stokes equations. Computed results at Re 34000 and 100,000 reveal the same phenomenon of delayed stall, as observed in the case of insects. Furthermore, the performance of flat plate, profiled and corrugated wing in a sweeping motion at a high angle of attack is also compared.