PRESSURE AND GENERALIZED FORCES FOR COMPLEX AIRCRAFT CONFIGURATIONS AND APPLICATION TO FLUTTER

A general method for steady and oscillatbry, subsonic and supersonic, poten-tial linearized aerodynamic flow around complex configurations is introduced. By applying the Green fundion method, a linear integral equation relating the unknown, small perturbation potential on the surface of the body, to the known downwash is obtained. The surfaces of the aircraft, wake and diaphragm (if necessary) are divided into small quadrilateral elements which are approximated with hyperboloidal surfaces. The potential and its normal derivative are assumed to be constant within each element. This yields a set of I inear algebraic equations. The ~oefficients are evaluated analytically. By using Gaussian elimination method, equations are solved for the potentials at the centroids of elements. The pressure coefficient is evaluated by the finite different method. The lift and moment coefficients are evaluated by numerical integration. Numerical results are presented. Applications to flutter are also included. i ACKNOWLEDGEMENT