Doublet-Point Method for Supersonic Unsteady Lifting Surfaces.

A method to predict unsteady aerodynamic forces on lifting surfaces in supersonic flow is presented. The wing is divided into small segments in which the lift force is expressed by a single-point doublet of the acceleration potential. This is the same concept as the doublet-point method developed by the authors for subsonic flows. In order to avoid sensitiveness to the Mach number, the upwash due to the point doublet is calculated by averaging over small areas. The integration is done analyticaly so that it requires no numerical quadrature. Pressure distributions are directly obtained as the unknowns of the algebraic equation. The results are compared with those obtained by other methods for various wing geometries, including the AGARD wing-tail configuration.

[1]  E. Behrens.  Reply by Author , 1968 .

[2]  B. Brock,et al.  The supersonic doublet-lattice method - A comparison of two approaches , 1975 .

[3]  Kenneth L. Roger.  Comment on "Doublet-Point Method for Supersonic Unsteady Lifting Surfaces" , 1985 .

[4]  Robert Thomas Jones,et al.  High speed wing theory , 1960 .

[5]  Robert H. Scanlan,et al.  A Modern Course in Aeroelasticity , 1981, Solid Mechanics and Its Applications.

[6]  A. M. Cunningham,et al.  Oscillatory supersonic kernel function method for interfering surfaces , 1974 .

[7]  L. J. Huttsell,et al.  Application of Three Unsteady Aerodynamic Load Prediction Methods. , 1974 .

[8]  Luigi Morino,et al.  Steady and Oscillatory Subsonic and Supersonic Aerodynamics around Complex Configurations , 1975 .

[9]  W. P. Jones,et al.  Unsteady supersonic aerodynamic theory for interfering surfaces by the method of potential gradient , 1977 .

[10]  Joseph L. Neuringer,et al.  Aerodynamic Flutter Derivatives for a Flexible Wing with Supersonic and Subsonic Edges , 1955 .

[11]  W. Rodden,et al.  A doublet-lattice method for calculating lift distributions on oscillating surfaces in subsonic flows. , 1969 .

[12]  L. Morino,et al.  A new unified approach for analyzing wing-body-tail configurations with control surfaces , 1976 .

[13]  R. Chipman.  An Improved Mach-Box Approach for Supersonic Oscillatory Pressures , 1977 .

[14]  W. P. Rodden,et al.  Kernel function for nonplanar oscillating surfaces in supersonic flow , 1971 .

[15]  Earl H. Dowell,et al.  A New Solution Method for Lifting Surfaces in Subsonic Flow , 1982 .

[16]  M. Hounjet,et al.  Improved Potential Gradient Method to Calculate Airloads on Oscillating Supersonic Interfering Surfaces , 1981 .

[17]  I. Lottati,et al.  Nonplanar, Subsonic, Three-Dimensional Oscillatory Piecewise Continuous Kernel Function Method , 1985 .

[18]  Charles E. Watkins,et al.  On the Kernel function of the integral equation relating lift and downwash distributions of oscillating wings in supersonic flow , 1955 .

[19]  J. Giesing,et al.  Oscillatory supersonic lifting surface theory using a finite elementdoublet representation , 1975 .

[20]  T. Ueda.  Expansion series of integral functions occurring in unsteady aerodynamics , 1982 .