ThePressure-Drag due to Blunt Leading Edges on Two-Dimensional Aerofoils, at Transonic and Low-Supersonic Speeds

Pressure drags, obtained from measured pressure distributions in the transonic and low-supersonic speed range, are compared for sharp and blunt leading-edged two-dimensional aerofoils. For the special blunt shapes considered here, the high pressures in the stagnation-point region are offset by low pressures generated further round on the leading edge and on the basic aerofoil itself. The result is that the changes in pressure drag due to blunting are small and in some cases favourable.