LIFT AND DRAG FORCE CALCULATION METHODS USING NON‐LINEAR SECTION DATA. HISTORY AND RECENT RESEARCH

Egidijus Pakalnis

doi:10.3846/16487788.2004.9635869

Abstract

In this article history and development of calculation methods of wing characteristics are presented. The development process includes the beginning in 1918 by Prandtl's classical lifting line theory and leads to resent research. The most attention is paid to non‐linear section data implementation methods in the calculation of finite span wing. The research of Philips and Snyder, Barnes, and Sivells and Neely is discussed.

Highlights

Developed during the period from 1911-1918, Prandtl’s classical lifting line theory is the base of most methods used for calculations of change of lifting force of 4flat, low sweep angle, and moderate and high aspect ratio wings [18]
With the assumption of a straight lifting line, the theory provides an analytical solution for the spanwise distribution of lift and induced drag acting on a finite lifting surface
The iteration is carried out until Γ distribution converges. This method was made popular by the NACA report of Sivells and Neely in 1947 that provides a detailed description of the method for unswept wings with arbitrary plan form and airfoil lift-curve slopes [22]

Summary

Introduction

Developed during the period from 1911-1918, Prandtl’s classical lifting line theory is the base of most methods used for calculations of change of lifting force of 4flat, low sweep angle, and moderate and high aspect ratio wings [18]. Sivells and Neely presented a method for calculating wing characteristics by lifting-line theory using nonlinear Unlike the classical lifting-line solution, the method presented by Phillips and Snyder is not based on a linear relationship between section lift and section angle of attack [16].

Results

Conclusion