Okinawa is subtropical islands and is enclosed in the ocean. There is a problem that corrosion of the structures progresses quickly because of sea-salt mist flying from sea. In this paper, The Authors investigate the relationship between corrosion and flow structures around the bridge beams as structures. Therefore, PIV is used to clarify the flow structures within the bridge beams and the corrosion within the bridge beams is guessed by a numerical approach by means of momentum equation of sea-salt particles.
Variable Geometry System(VGS) turbochargers are widely applied to automotive diesel engines in order to improve the engine performance the design of a VGS turbine nozzle is crucial to ensure the engine requirement. In a current design of a VGS nozzle, two dimensional vane profile is commonly applied, but a three dimensional vane profile can be adopted due to the recent progress of a metallurgical technology. In this study, the effects of three dimensional VGS nozzle vane on turbine performance and aerodynamic force of nozzle vane, which will affect controllability of boost pressure, are investigated numerically and experimentally.
To achieve sustainable society, a hydroturbine with not only the large but also small/mini/micro capacities have been paid attention for power generation. A cross-flow turbine can work effectively at comparatively low head and/or low discharge, and a runner and an inlet nozzle profile have been optimizing. In this paper, the model turbine was prepared in accordance with a traditional design, and the performances and the flow conditions were investigated experimentally at various operating conditions. The hydraulic efficiency is doubtlessly maximum while the guide vane is at the normal/design position and deteriorates in a lower discharge adjusted by the guide vane. Such deteriorations are caused by unacceptable flow conditions in the inlet nozzle. To improve the efficiency dramatically in a lower discharge, the guide vane equipped with a current plate was proposed and the fruitful effect of the plate about the efficiency was confirmed experimentally.
The flow field around a vertical axis wind turbine is much complicated because the relative flow velocity and the angle of attack to the blade are much changed during rotation. The two-dimensional flow field around a straight-bladed vertical axis wind turbine under operation and the pressure distribution on the surface of the rotor blade were measured in wind tunnel. The flow field and blade load under the different operating conditions were investigated. The velocity deficit in wake region due to rotating blade is also shown. The pressure difference between pressure and suction surfaces becomes large when a blade is passing at the upstream position.
A hydraulic turbine for open channels does not need incidental facilities for conducting water. It is applicable even if an effective head is comparatively low. However, because the rotational speed is low, the hydraulic turbine has a tendency to enlarge. Therefore, the hydraulic turbine is fixed to a setting position. A new portable hydraulic turbine that utilizes the kinetic energy of an open-channel flow, such as a river or an irrigation canal, has been proposed. This hydraulic turbine has added a collection device to the axial flow runner with the aim of increasing output by collecting and accelerating the flow. In this study, characteristics and flow fields of the runner simple substance, and the complex of the runner and collection device which differ in number of blades are clarified by numerical analysis. Furthermore, the effect of the number of blades
on the performance of this hydraulic turbine is clarified.