CALCULATION OF NON-LINEAR AERODYNAMIC STABILITY DERIVATIVES OF AEROPLANES
Abstract
Non-linear dependence of lift and pitching moment on the angle of attack occurs especially with slender bodies, for example aerofoils of small aspect ratio and slender bodies of revolution. This is due to the lateral flow around such bodies, which leads to lateral separation and the creation of free vortices on the upper surfaces. Since viscous effects and flow separation determine the magnitude of the non-linear effects, theoretical prediction of these phenomena is very complicated. A survey is presented of existing methods for calculating non-linear effects and the various methods with their different vortex patterns are compared. A new method for calculating the lift distribution for wings with sharp leading edges in incompressible flow is also presented. This method gives the non-linear dependence of the lift and pitching moment on the angle of attack without using empirical data. It can be considered as an extension of the linear lifting-surface theory of E. Truckenbrodt (WGL-Jahrbuck 1953). It is valid for arbitrary plan forms and aspect ratios. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1961
- Accession Number
- AD0275411
Entities
People
- K. Gersten
Organizations
- AGARD