Abstract
As for propeller fan, the internal flow structure and the noise characteristic are known to be different according to operation point. However, the relation between them is not so clear. In this paper, measurement of the downstream of propeller fan by hot-wire probe and the pressure fluctuation of the casing wall was carried out, and the following results were obtained. The higher the flow ratio is, the closer the tip vortex reaches the downstream to the blade that discharges it. As for magnitude of velocity fluctuation, pressure fluctuation of the casing wall and noise level, the tendency to the flow ratio is different respectively.
