Numerical and Experimental Study of Flow Structure of Low-Aspect-Ratio Wing

摘要

Unsteady aerodynamic characteristics of a low-aspect-ratio elliptic wing with an E-174 aerofoil are studied by numerically solving unsteady incompressible Navier-Stokes equations. Two phenomena have been found: The first phenomenon is found at angle of attack larger than 11 deg, where the flow around the wing becomes bilateral asymmetric. This phenomenon is caused by tip vortices' destabilization. Tip vortices' destabilization is due to interaction between a secondary separated vortex and the tip vortices. The second phenomenon is found at angle of attack larger than 33 deg, where a large separated vortex stays above the wing, forming a stationary vortex. The stationary vortex is thought to be related to the vertical component of the tip vortices. Experimental flow visualization has verified the phenomena found in the numerical simulation.