Studies on the Vortex Pump : 3rd Report, Estimation of Pump Performance

The internal flow conditions and the pump performance were discussed in the first and second reports, respectively. Based on the results presented in the former reports, the following two facts are derived in this report. The first fact is that the flow through the impeller increases as the blade angle decreases, owing to a difference in degree of reaction. The second fact is that the boundaty radius of the impeller inlet and outlet regions and the mean impeller outlet radius of the through-flow increase with a decrease in blade width. This is ascribed to the connection between the flow through the impeller and the crosssectional area of the impeller passage. Futhermore, semi-experimental equations of slip factor are derived from theoretical blade load values and experimental slip values. Based on the above results a method of estimating pump performance is shown.