Passive Flow Control over an Airfoil by Control Rod at Low Reynolds Number

In the present study, the flow control mechanism of SD۷۰۶۲ airfoil by a rod illustrated using Particle image velocimetry (PIV) technique at pre-stall angles of attack at Reynolds number of Re = ۳۰۰۰۰. The rod was installed on the suction surface of the airfoil at different chordwise locations. Diameter of the rod was normalized with the chord length of the airfoil and three diameter ratios (d / c = ۰.۰۱۷, ۰.۰۳۳ and ۰.۰۴۴) were examined at angles of attack of α = ۶°, ۸° and ۱۰°. Formation of laminar separation bubble for the baseline airfoil and the effect of rod on the laminar separation bubble were investigated in detail. It is observed that the height of boundary layer was reduced up to ۲۲% by proper rod location and diameter ratio. Moreover, the rod suppressed the unsteady vortices over the suction surface of airfoil significantly. Therefore, the peak magnitudes of turbulent statistics were also decreased up to ۳۰% by the rod.

Keywords:

Airfoil , Control rod , Flow control , Low Reynolds Number flow