Calculation of nonlinear subsonic characteristics of wings with thickness and camber at high incidence

A new vortex lattice model for the calculation of the flow over delta-shaped wing planforms at high angles of attack in subsonic flow is presented. This model enables the prediction of the aerodynamic coefficients and the pressure distributions for a wide range of wing planforms, in particular for delta-shaped wings with and without camber. The new vortex lattice model is combined with the panel source singularity for the calculation of the aerodynamic characteristics of thick wings having sharp leading edges. The calculated aerodynamic characteristics are in very good agreement with experimental data, while reasonable agreement is obtained in the evaluation of the pressure distributions. A parametric study of the numerical model and some numerical considerations which enable considerable reduction in computer time are also discussed.

[1]  F. Johnson,et al.  A three-dimensional solution of flows over wings with leading-edge vortex separation , 1976 .

[2]  D. Hummel,et al.  Experimentelle Bestimmung der gebundenen Wirbellinien sowie des Strömungsverlaufs in der Umgebung der Hinterkante eines schlanken Deltaflügels , 1972 .

[3]  M. A. Epton,et al.  Three-Dimensional Flow over Wings with Leading-Edge Vortex Separation , 1980 .

[4]  W. H. Wentz,et al.  Vortex breakdown on slender sharp-edged wings , 1969 .

[5]  Ali H. Nayfeh,et al.  Nonlinear prediction of the aerodynamic loads on lifting surfaces , 1976 .

[6]  E. C. Polhamus,et al.  Application of the leading-edge-suction analogy of vortex lift to the drag due to lift of sharp-edge delta wings , 1968 .

[7]  A. H. Nayfeh,et al.  Three dimensional steady and unsteady asymmetric flow past wings of arbitrary planforms , 1977 .

[8]  R. J. Margason,et al.  Vortex-lattice FORTRAN program for estimating subsonic aerodynamic characteristics of complex planforms , 1971 .

[9]  E. Polhamus.  A concept of the vortex lift of sharp-edge delta wings based on a leading-edge-suction analogy , 1966 .

[10]  Paul E. Rubbert,et al.  An improved method for the prediction of completely three-dimensional aerodynamic load distributions of configurations with leading edge vortex separation , 1976 .

[11]  J. H. B. Smith,et al.  A theory of the flow past a slender delta wing with leading edge separation , 1959, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[12]  R. J. Vidal,et al.  Experimental Investigation of Influence of Edge Shape on the Aerodynamic Characteristics of Low Aspect Ratio Wings at Low Speeds , 1955 .

[13]  I. H. Abbott,et al.  Theory of Wing Sections , 1959 .

[14]  E. Polhamus.  Predictions of vortex-lift characteristics based on a leading-edge suction analogy. , 1971 .

[16]  W. Wentz.  Effects of leading-edge camber on low-speed characteristics of slender delta wings , 1972 .