Abstract: A new method based on lifting-surface theory is presented determining the load distributions on finite wings in subsonic flows. A spanwise strip together with a classical chordwise series are used. By exchanging the order of the Mangier-type doubly singular integral, as justified in this paper, is made in order to make the calculations analytical and simple. A segmented polynomial approximation for the integrand of the chordwise integral is deduced to evaluate the kernal function in a closed form finite-sum manner, resulting a well-behaved coefficient matrix. Aanalytical results are compared with experimental data and other methods; the computational efficiency is demonstrated.

Key words: lifting surface, subsonic flow, numerical calculation