Effects of Coefficient Errors on the Performance Predictions of a Typical Fighter at Medium Altitude

Performance prediction is one of the primary uses of wind tunnel data. Uncertainties in the tunnel data are therefore directly related to errors in performance predictions. The objective of this study was to examine the effects of aerodynamic coefficient errors on the point performance predictions for a typical fighter at medium altitude and subsonic velocity. The point performance parameters were formulated as functions of the aerodynamic coefficients. A computer program was written to calculate the selected performance parameters for 121 cases, each case representing a different combination of coefficient errors. The result was the correlation of the percentage error in the point performance parameters as a function of the percent errors in the aerodynamic coefficients. The use of these techniques would result in move efficient testing through the identification of regimes where test data accuracy is critical for accurate performance prediction.