Theoretical investigation of sailwing airfoils taking account of elasticities

Abstract

In a previous paper by these Authors (see last Abstract), in which a theoretical method for predicting the aerodynamic characteristics of a sailwing was presented, it was assumed that the trailing-edge position and the slackness in the wing surfaces remained fixed. However, when the sailwing is loaded the elasticities of the trailing-edge wire and of the wing surfaces cause the trailing edge to move and the surfaces to elongate. In the present paper, a two-dimensional theoretical model of each aerofoil section is used to simulate the three-dimensional characteristics of a sailwing, and a theoretical method is presented for the numerical analysis of two-dimensional double- and single-membrane sailwing aerofoil,s taking into consideration the deflection of the trailing-edge wire and the elongation of the membrane due to the aerodynamic forces. Development of the method, and results obtained, are discussed in some detail, and several conclusions are drawn.