Theoretical Distribution of Lift on Thin Wings at Supersonic Speeds (An Extension)
Abstract
A derivation is presented of a point-source method based on the linearized theory for obtaining the pressure coefficient on thin wings at supersonic speeds. The method is applied to calculate the lift distribution of a thin flat-plate wing having a straight leading edge and an arbitrarily curved wing tip whose elements are swept behind the Mach angle. A qualitative basis for obtaining solutions that satisfy the Kutta-Joukowski condition is included. The analysis is continued to formulate the velocity potential for regions influenced by so-called subsonic trailing edges (that is, edges where the component of the free-stream velocity normal to the trailing edge is subsonic). The derivations include the solution that satisfies the Kutta-Joukowski condition or any of the infinite number of transition solutions involving a discontinuity in the cross velocity (sidewash) in the wake of a subsonic trailing edge. As an example, the two perturbation-velocity components in the plane of a trapezoidal wing and the upwash over the wing tip are evaluated. By means of series expansions, the mathematical nature of the lift distribution in regions influenced by arbitrary subsonic trailing edges is indicated when the Kutta-Joukowski or some other condition is applied to make the solution unique.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1948
- Accession Number
- ADA381443
Entities
People
- John C. Evvard
Organizations
- National Aeronautics and Space Administration