Development of Savonius Rotors Integrated into Control Valves for Energy Harvesting

Abstract

Integrating vertical-axis runners into ball valves for energy harvesting from pressurized pipes in water supply systems has become a promising scheme of self-supplying power (referred to as the “GreenValve” scheme). In addition to energy harvesting, the GreenValve configuration also has the function of fluid regulating, which makes a qualitative breakthrough in both structure and function. However, the runner specially used to match the ball valve has not been fully studied and designed. Hence, based on the traditional Savonius rotor, a modified semi-elliptical runner is proposed in this study. To better match the ball valve structurally, the roundness of the runner at blade tip position is improved and, thus, the initial runner configuration is obtained. Moreover, research on blade profile flatness and runner aspect ratio is conducted in FLUENT software to be more functionally compatible with the ball valve. Numerical results indicate that the GreenValve always performs best in terms of shaft power at 25% opening regardless of the aspect ratio and the flatness. When the flatness value is equal to 0.7, the GreenValve presents the maximum shaft power and the second highest flow coefficient which is only 1.9% lower than the maximum value. Comparison results of three models with different aspect ratios reveal that the model with the smallest aspect ratio has a slight reduction in flow capacity while a significant improvement in shaft power, reaching a maximum shaft power of 78.6W.

A Novel Train Roof-Top Wind Energy Conversion System

“…Equations ( 10) and ( 11) are used to estimate the value of the traction force and traction power applied to trains without the necessary extra equipment and power to manage it. In any event, the train drag force and the power needed for it to be overcome are given by [68]: For a new model, a similar calculation might be carried out by simply summing the drag forces on the train, the wind turbines, and a streamlined aluminum deflector, like the gearbox, and generator both lie underneath. However, it should be borne in mind that holes and gaps on the body surface enhance air reluctance; so, the air drag induced by the airfoil deflector and wind turbine is computed and integrated individually to take account of the worst-case situation.…”