Tests on a Control with Fixed Trailing-edge Angle, and Surfaces of Variable Camber

摘要

The report describes experiments to determine the effect of surface distortion on the hinge moments of a control and to investigate the importance of a rigid trailing edge in the prevention of large changes in hinge-moment coefficient.nThe results shows that by designing the control so that the surface at the trailing edge, extending over one-eighth of the chord, is incapable of distortion, then the value of b2 remains almost constant within the limits on any possible distortion forward of the fixed portion. It has also been found that b1 is more constant. Changes in centre-line camber of the deformed portion of the control can still produce an effective change in b2 when the camber varies with the control angle, although the amount of this change may be roughly halved. Present practice of treating trailing-edge angle as an important parameter in specifying control characteristics is well justified.