Performance Criteria for Positive-Displacement Pumps and Fluid Motors

Abstract The comparison of performance characteristics of positive-displacement pumps and fluid motors on the basis of dimensionless performance coefficients and dimensionless efficiency curves is presented as a substitute for the present methods. It is shown that the coefficients describe performance adequately and are subject to significant interpretation in terms of the geometry of the unit. The dimensionless efficiency curve is shown to have advantages in presenting a wide range of data and in prediction of performance characteristics under any specified operating conditions.