CORRECTIONS FOR MEAN-VELOCITY AND TURBULENCE MEASUREMENTS FOR HIGH TURBULENCE LEVELS

The influence of the different functional forms of the probability density of the velocity variation on the measurement of mean velocity by hot wire or by mechanical means and on the measurement of turbulence by hot wire is examined. To coyer a large range, four probability-density functions are chosen, namely, a normal, a triangular, a rectangular, and a sinusoidal function. For simplification, the fluctuation of velocity only in the direction of the resultant mean velocity is considered. It is found that for high turbulence level the discrepancy between a measurement and the true value depends primarily on the intensity of turbulence and secondarily on the distribution form.