New Methods for Predicting Nonlinear Lift, Center of Pressure, and Pitching Moment on Middile Configurations

Book excerpt: A new semiempirical method has been developed to predict normal force, pitching moment, and center of pressure on missile configurations up to angles of attack of 30° The method is based on linear theory and slender body techniques at low angle of attack and uses wind tunnel data to derive nonlinear angle-of-attack corrections as angle of attack increaces. The new improved theories include body alone, wing alone, and body-wing and wing-body interference. While the new theory is databased, simple analytical formulas are derived that allow general use of the techniques. Comparison with the linearized approaches used in the former NSWCDD aeroprediction code shows singificant reductions in errors of aerodynamics above 5° to 10° angle of attack. Limited comparisons to other state-of-the-art engineering codes show the new theory to be as good as or better than anything known to be available for computing planar aerodynamics up to 30° angle of attack.