Detailed flow measurements within the volute of an automotive HVAC blower

Experimental data that characterize the flow field within the volute of an automotive HVAC (heating/ventilation and air conditioning) blower have been acquired and analyzed. The single inlet blower consisted of a forward curved (FC) blade impeller and volute with a simple rectangular cross section. The performance characteristics of FC blowers makes them especially desirable for automotive applications given the tight packaging constraints of automotive systems. However, the FC blower is an inefficient flow device and is the dominant contributor of noise in the vehicle cabin at high blower speeds.; Velocity and pressure measurements have shown the volute flow field to be highly three-dimensional with significant turbulence levels. These measurements have also revealed the well known salient flow features associated with blowers, such as the “jet wake” pattern, the “double vortex” secondary flow, and the inefficient use of the impeller width. These features are believed to be significant loss and noise generation mechanisms. Insight on how the impeller/volute interaction may contribute to these features is presented. The results of this study may be of particular interest to the designers of such blowers and to those persons who wish to validate their CFD predictions.