ESDU 74011:1997

ESDU 74011 gives curves derived from lifting-surface calculations for flap effectiveness (rate of change of lift coefficient with flap deflection) as a function of wing lift-curve slope, flap chord/wing chord ratio, wing aspect ratio and thickness, Mach number below subcritical, and Reynolds number. Predictions from the curves have been compared with experimental data from 10 sources and yield flap effectiveness to 0.2 per radian To correct the data, which apply to plain flaps and controls (ailerons, elevons and elevator) on straight-tapered lifting surfaces, for application to part-span, ESDU 74012 is used.