Effects of different geometries on boundary layer transition

The aspect ratio of the leading edges is crucial for wind tunnel test. However, manufacturing of high aspect ratio samples could be very time consuming and extremely expensive. Experimental and computational investigation has been carried out on transitional boundary layers subjected to changes in the leading edge geometry. The aspect ratio of the elliptical leading edges was changed and its impact on boundary layertransition was observed. The displacement thickness, shape factor, skin friction coefficient and the pressure gradient were plotted to study the impact of each leading edge. The impact of the curvature of the elliptical leading edges was also documented. The data shows that as the aspect ratio increases transition onset gets delayed. Conditional results are presented that indicate that the gradient and the curvature of the leading edge plays a significant role in influencing the transition onset location. The presence of a higher aspect ratio leading edge reduces the turbulent spot propagation rate which is one of the primary causes of boundary layer transition.