Book Description

A theoretical study is made of some cruciform-wing arrangements and their wakes by means of slender-body theory. The basic ideas of this theory are reviewed and equations are developed for the pressures, loadings, and forces on slender cruciforn wings and wing-body combinations. The rolling-up of the vortex sheet behind a slender cruciform wing is considered at length and a numerical analysis is carried out using 40 vortices to calculate the wake shape at various distances behind equal-span cruciform wing at 45 degrees bank. Analytical expressions are developed for the corresponding positions of the rolled-up vortex sheets using a 4-vortex approximation to the wake, and these positions are compared with the positions of the centroids of vorticity resulting from the numerical analysis. The agreement is found to be remarkably good at all distances behind the wing.