Abstract
Effects of blade shapes and angles on the over all performances of sirocco fans was considered experimentally using nine various impeller within the same casing. Nine impellers have the different inlet, outlet angles and blade inclinations. At first, the relation of pressure, efficiency with dischage were measured. The considerations of effects of the blade inlet, outlet angles and blade inclinations on the over all performances were considered. Unsteady velocity distributioins at the impeller outlet were also measured using hot-wire-probe for four impellers with the better performances. Unsteady velocity distributions and flow deviation angles at the impeller outlet were calculated using the measured results. Relation between the over all performances and velocity distributions at the impeller outlet were examined. Blade inlet and outlet angles, and blade inclination to have the best performance were considered.