Predicting maximum lift coefficient for twisted wings using lifting-line theory

A method is presented that allows one to predict the maximum lift coefficient for a wing from knowledge of wing geometry and maximum airfoil section lift coefficient. The method applies to wings of arbitrary planform and includes the effects of twist and sweep. In addition to predicting the section lift distribution for a wing of known planform with a known twist distribution, the method can be used to predict the twist distribution, which will produce any desired section lift distribution along the span of an unswept wing of any given planform. The method is shown to predict the twist distribution required to minimize induced drag and is also used to predict the twist distribution that maximizes the wing lift coefficient, while keeping the total amount of required twist at a practical level.