Nonlinear aerodynamic global model indentification using Gram-Schmidt orthogonalisation13;

This paper discusses a simple technique to identify global models for nonlinear aerodynamic force and moment coefficients of aircraft using multivariate orthogonal functions. Classical Gram-Schmidt procedure and Predicted Squared Error metric are used to generate the orthogonal functions. Global models for the F-16 aircraft are identified from a simplified subsonic (Mach less than 0.6) wind tunnel database available in open literature. The identified models are compared with those found in literature for the same wind tunnel database and conclusions are drawn.