Aerodynamic Characteristics of a Straight Wing in a Circular Tunnel

Abstract

A straight wing lying on a diameter of a circular closed tunnel is studied, where minimum induced drag is assumed. Exact expressions of spanwise lift distribution and induced drag are obtained from the TREFFETZ plane. When the ratio of wing-span to tunnel-diameter increases, lift distribution changes gradually from elliptic to uniform distributions, and induced drag gradually decreases until it becomes zero in the limiting case when the ratio reaches unity.