Experimental and numerical studies of low aspect ratio wing at critical Reynolds number

In this study, the three-dimensional flow behaviors and aerodynamics characteristics of a NACA0003 wing with an aspect ratio (AR) of 1 at Reynolds numbers of 1.0×10⁵ has been investigated both experimentally and numerically. The force measurement and flow visualization (oil flow visualization) through the wind tunnel experiment were applied to verify the reliability of the simulation. The investigation with different angles of attack reveals that flow structure contained three dimensional laminar separation bubble (LSB) and wing-tip vortex. As increasing angle of attack, the area occupied by LSB expands both streamwise and spanwise. The wing-tip vortex has strong impact on the formation of LSB. In addition, the spanwise load distribution has shown that both three dimensional LSB and wing-tip vortex provide additional vortex force.