IHS ESDU Normal force of low-aspect-ratio cropped-delta wings up to high angles of attack at subsonic speeds. 93034

ESDU 93034 presents graphical data at taper ratios of 0, 0.5 and 1 applying at Mach numbers of 0.5 and below, and at Mach numbers of 0.8 and 0.95. They were obtained by correlating experimental data drawn from the literature for delta, cropped delta and rectangular thin, uncambered and untwisted, sharp-edged wings of aspect ratio from 0.2 to 4 and apply up to angles of attack of 35 degrees, that is up to the stall. Below an angle of attack of 5 degrees, the normal force is obtained from the normal-force-curve slope at zero angle of attack, and a graph is provided for that based on the method of ESDU 70011. The accuracy of the method is within 5 per cent. The flow phenomena and the behaviour of the normal-force curve over a wide angle of attack range is discussed, with particular emphasis on delta wings. An analysis of more limited data enabled a correlation to be developed above the stall for thin (thickness/root chord less than 0.02) sharp-edged delta and rectangular wings of aspect ratio from 0.25 to 4 at low speeds. The data were available to angles of attack of 70 degrees and were extrapolated to 90 degrees guided by the correlations of ESDU 70015.