The present study is a fundamental approach to reveal the minute fluctuating pressures on three-dimensional blade surfaces of a basic propeller fan. Because, among the concerning physical quantities, the unsteady pressures on the rotating blades give us useful information for the fan flow and its sound-noise level. The authors correct the centrifugal-force effect, the gravitational-force effect and the other leading-error effects for accurate measurements of the minute pressures using a measuring technology developed by the authors (Hirata et al., 2009). As a result, we show the Reynolds-number effects and the spatial distributions on the blade of both time-mean pressure and pressure-fluctuation intensity.
