Identification of Uncertainties Caused by Flow Qualities

Abstract

: It is necessary to assess flow qualities more precisely to estimate uncertainties of the wind tunnel test data at higher angles of attack and lower Mach numbers. Then the uncertainties caused by the flow qualities attempted to be identified by repeat tests at different positions in a supersonic wind tunnel. First, the applied conditions were described through the discussions of typical error contributors in the aerodynamic force testing. Next, the standard errors of estimate of the aerodynamic coefficients against angles of attack were calculated from the scattered repeat test data to compare with the uncertainties estimated by the flow calibration data. Finally, the correction factors were introduced to error sensitivities of the flow uniformities to identify the standard errors of estimate caused by the different flow fields. The identified flow quality errors can be applied to estimate data uncertainties of any aerodynamic phenomenon around the similar model shape.