Effect of endplates on two-dimensional airfoil testing at low Reynolds number

The presence of endplates (or sideplates) in two-dimensional wind-tunnel force measurements on airfoils has a strong effect on lift and drag coefficients at low Reynolds numbers. Results on an Eppler 61 airfoil indicate that the endplates are responsible for a sharp decrease in the airfoil performance. The lift coefficient is reduced and the drag coefficient is increased due to the interaction of the airfoil boundary layer with the sideplate boundary layer.