Pressure and Shear Stress Measurement Uncertainty for DARPA SUBOFF experiment

Abstract : An uncertainty analysis of the pressure and shear stress measurements in the SUBOFF experiments is presented. Error sources in the measurements are identified, characterized as to the types of error that will results, and then quantified. The propagation of errors in the pressure and friction coefficients is approximated with a Taylor series and the 95% confidence intervals for Cp and Cf are presented as a function of the coefficients themselves and thermal drift in the electronics. It is concluded that the true value of the pressure coefficient is within 0.005 to 0.01 of the measured value, and the true friction coefficient is within 0.0002 of its measured value. Keywords: Pressure measurement; Shear stress; Pressure distribution; Obstacle block.