An analysis on three-dimensional viscous flow fields in the volute casing of a small-size turbo-compressor

The flow fields in the volute casing of a small-size turbo-compressor at different flowrate (design point ±20%) are studied by numerical analysis. The governing equations for three-dimensional, steady, viscous flow are solved using SIMPLE algorithm with commercial code of STAR-CD. Numerical results show that the three-dimensional flow pattern inside the volute casing of a small-size turbo-compressor is strongly influenced by secondary flows that are typically created by the curvature of the casing passages. The flow pattern in the casing also affects the performance of the turbo-compressor. In order to elucidate the loss mechanism through the volute, we prepared the secondary flow, velocity magnitude, and static pressure distribution at the four cross-sectional planes of the casing