Divergence Structural Analysis of an Aircraft Tapered-Unswept Wing Using Aerodynamic Strip Theory for the Case of Flight at Sea Level

Abstract

This study investigates the utilize of the iteration of matrix numerically to get the divergence speed of an aircraft tapered-unswept wing via using method of strip theory (without finite span correction and with finite span correction). The 2-D fluid flow across the wing airfoil section is assumed by the aerodynamic strip theory and then integrated over wing span. In the present work, first the tapered unswept wing is divided into four Multhopp’s stations. Then, elastic properties of this wing in relation to torsional influence coefficients related with this four Multhopp’s stations have been evaluated. Second, equations for equilibrium are constructed as integral equations. Then, an appropriate aerodynamic theory in the form of strip theory was addressed, as well as the technique of solution for determining the divergence speed. Finally, using strip theory, the integral equation has been expressed in matrix form. Iteration of matrix has been done using MATLAB environment to reach for the solution to converge. Also, an increase of 15% in torsional stiffness of aircraft wing has been considered to illustrate its effects on torsional divergence speed of aircraft wing. The attained results are going to be helpful in understanding of wing instability for modern aircraft designer.