Performance of Aerofoils with Lift Devices at Low Reynolds Numbers for Use on RPV (Remotely Piloted Vehicles) Wings

摘要

The effect of low Reynolds numbers upon the characteristics of simple high lift devices for operation on remotely piloted vehicle wings was tested. The wing section profiles and devices tested were: a NACA 23015 airfoil with a 30% chord plain flap, and a NACA 4415 airfoil with a 23% chord split flap, a 23% chord zap flap, a 20% chord Kruger flap, and a combination of the Kruger and zap flaps. Variations in lift, drag, and pitching moment of these devices were investigated over a Reynolds number range of 140,000 to 300,000. No serious deterioration in the capability of the devices is observed, however, reductions in lift which result in positive increments in pitching moments do occur as the Reynolds number is reduced. The relative merits of the combinations are unchanged as the Reynolds number is reduced, the greatest lift increase coupled with a smooth pitching moment being displayed by the Kruger and zap flap combination.