A Rapid Method for Predicting the Off-Design Performance of Radial-Inflow Turbines

An explicit expression for predicting the turbine off-design performance in terms of efficiency, torque, and mass flow as a function of tip speed with pressure ratio as a parameter is formulated. The results of this method have been compared with those of various experiments and more elaborate prediction methods; satisfactory agreement is obtained.

Comparison of Some Analytical and Experimental Correlations of Axial-Flow Turbine Efficiency

The first phase of the axial-flow turbine design problem involves selection of a velocity diagram. This choice exerts an important influence on turbine efficiency. Design charts relating turbine efficiency to the velocity diagram, through a work coefficient and a flow coefficient, are therefore useful in preliminary design. In this study such design charts are constructed using two established analytical methods. The results are compared with a published correlation based on experimental data. Simple constructional methods are indicated whereby these charts can be used to obtain preliminary estimates of rotor blade stress and relative temperature, two factors influencing blade life.