Double suction volute pumps are used in many fields such as water facilities, power plants and the oil refineries and petrochemical plants. The authors have designed two types of double suction volute pumps for the purpose of high efficiency and low shutoff head ratio using the optimized design approach with DoE (design of experiments) and CFD. We reconfirmed the importance of not only impeller design optimization but also suction casing and discharge volute design optimization to achieve these objectives. Some experiments were conducted using scale-down model pumps and the performances of them were equivalent to the prediction performances.

A wind turbine operates in turbulent natural wind. In particular, the unsteadiness and turbulence of wind in Japan are stronger than one of Western countries-Europe, America and others in general. Therefore, the authors take account of the unsteadiness of natural wind in installed open-air location for a designed rotor blade in order to make higher performance. The present paper describes the effects of sinusoidal velocity fluctuation, turbulent intensity and vortex scale of simulated natural wind on performance of a horizontal axis wind turbine (HAWT). Using five wind turbine rotors on the basis of NACA and MEL type blades, experimental results are mainly presented to demonstrate the dependency of wind frequency, vortex scale of the wind. In particular, one of designed MEL-type rotors indicates 30% larger power coefficient in simulated natural wind than one in steady wind.

Recently, centrifugal compressor for turbocharger is needed to improve surge margin and efficiency at low engine speed region. In this study, three compressors which have the same A/R (a ratio of volute throat section area to centroid radius of the section) volutes but different configurations are investigated by using CFD and experiment. And the same impeller is used in all cases. In the experiment, not only total performance of compressor but also static pressure distribution at volute wall is measured. Three compressors have the different performance. In conclusion, under the same A/R condition, larger frame size and smaller overhang volute show better performance because of no separation in its passage.