Low Reynolds Number Flow over Low Aspect Ratio Corrugated Wing

Voluminous research exists on the effect of combination of low Reynolds number flow over low aspect ratio flat plate wings for usage in micro-aerial vehicles and UAVs, as they also fly under similar conditions and combination of low aspect ratio and low Reynolds number. It has been well established by many researchers (Torres and Mueller in AIAA 42(5):865-873, 2004; Okamoto and Azuma in AIAA 49(6):1135-1150, 2011; Mizoguchi and Itoh in AIAA 51(7):7-52, 2013; Shields and Mohseni in AIAA 50(1):85-99, 2012; Mizoguchi and Kajikawa in Trans Jpn Soc Aero Sp Sci 59(2):56-63, 2016; Pelletier and Mueller in J Aircr 37(5):825-832, 2000; Liu and Hsiao in J Mech 28(01):77-89, 2012; Taira and Colonius in J Fluid Mech 623:187-207, 2009) that low aspect ratio wings in low Reynolds number flow gives a higher lift coefficient and stall angle is also increased which is quite different from the high aspect ratio wing. Also, it is a well-established fact in the existing literature that linear theories cannot be applied as in case of high aspect ratio wings because of non-linear increase in lift coefficient. The reason for such increase in lift and stall angle has been attributed to wingtip vortices that become prominent in low aspect ratio wings called the vortical lift which keeps on increasing up to a certain high angle of attack till it interacts with the separation bubble. In the past, very limited work has been done to study the vortices and their contribution in enhancement of aerodynamic characteristics. In the present work, flat plate model with corrugations at an aspect ratio (AR) of 1.0 are studied and compared with flat plate wing of AR 1.0; also flow visualization in water tunnel has been carried out at Reynolds number of 10(2) to ascertain the flow physics involved.