First-Quadrant Two-Phase Flow in Centrifugal Pumps.
MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF ELECTRICAL ENGINEERING
Pagination or Media Count:
A pump system was built and instrumented on which tests were performed yielding single- and two-phase actual pump characteristics for first-quadrant operation forward flow and forward rotation of two different centrifugal impellers mounted in a simple two-dimensional volute. Theoretical single- and two-phase pump characteristics were determined from the impeller geometry, the Euler equation, and the use of the two-phase flow function. The head-loss ratio, the loss of head in two-phase flow dividied by the loss of head in single-phase flow, was then plotted versus void fraction. The results were compared to an earlier theory proposed which predicted the head-loss ratio to be primarily a function of void fraction. These results indicate that the head-loss ratio is a function of flow coefficient as well as void fraction. Flow-visualization studies were also conducted and revealed that flow regime inside the blade passages can be different from either the inlet or outlet flow regimes, and greatly affects pump performance. Further experimentation, on a more efficient system employing higher-specific-speed impellers, is recommended to study more closely the effect of flow coefficient, flow regime and void fraction upon two-phase pump performance.
- Hydraulic and Pneumatic Equipment
- Fluid Mechanics