Abstract
Higher specific speed of axial flow pump follows a strong demand for more compact structure but yields deterioration of pump efficiency and cavitation performance. One solution might be adoption of contra-rotating pump. The previous experimental results implied its possibility although guideline of rear rotor design was not found because of the complexity of internal flow. Numerical analysis was performed with a method of commercial code to consider the optimum design of rear rotor. Numerical results are compared with experimental ones for two kinds of rear rotors tested. And further improvements of pump performance are considered from numerical results for rear rotors with various design parameters.
