An Experimental Investigation of the Flow Field Pattern within the Impeller of a Cross-Flow Fan

Cross-flow fan performance is strongly influenced by the geometry of the casing, as the latter, in turn, affects the position and the strength of the eccentric vortex that characterizes the operation of this category of fans. The paper presents a systematic experimental investigation of the flow field within the impeller at different throttling conditions and for different geometries of the fan casing. Both pressures and velocities are measured using a three-dimensional five-hole probe that is inserted in the flow. This study helps determine the relationship between the design parameters of the casing and the flow field pattern, and it is part of an extensive work, by the same research group, aimed at establishing a general theory on cross-flow fan operation and at outlining the design guidelines for this particular type of turbomachines