Volute Pressure Distribution, Radial Force on the Impeller, and Volute Mixing Losses of a Radial Flow Centrifugal Pump

A standard volute-type, radial-flow, centrifugal pump was instrumented to obtain the pressure distribution in the volute and also the bearing reactions from the pump hydraulic force transmitted to the shaft. The resultant force from the integrated pressure distribution was found to give a reasonable design approximation of the radial force. An analysis of hydraulic conditions within the volute gave pressure distributions and radial-force magnitudes that were comparable to those measured with certain qualitative interpretations about internal recirculations. In addition, the pressure-distribution analysis furnished an interpretation of the effect of the volute on the pump head-capacity performance with corrections to the impeller head. The predicted head-capacity relationship had the form of the measured pump performance.