POA * ONLINE SUBSCRIPTION ONLY

ESDU 83040 gives a simple and rapid means of estimating the spanwise loading of a wide range of cambered and twisted wing planforms for unseparated subcritical flow. It is based on lifting-surface theory and extends, to take account of camber and twist, the basic method of ESDU T.D. Memor. 6403 for spanwise loading due to incidence of uncambered and untwisted wings. The effect of camber is treated by considering it as imparting an equivalent incremental twist to the wing. A simple artifice is used to represent the twist distribution by a combination of linear segments. From the linear representation effective values of local twist are devised for use in the method. Spanwise loadings can be estimated either at a given incidence or a given wing lift coefficient. The method is applicable to wing planforms for which the reduced aspect ratio (βA) is in the range 1.5 to 12 and the sweep parameter (AtanΛ½) is in the range 0 to 6. The wings can have any taper ratio (λ) between 0 to 1 with straight, cranked or curved leading edges, and straight or cranked trailing edges. The method is illustrated by three worked examples.

A computer program, ESDUpac A9510, described in ESDU 95010, is available that calculates the spanwise loadings directly from steady liftingsurface theory using the Multhopp-Richardson solution.