Department of Mechanical Engineering, Faculty of Engineering
Department of Mechanical Engineering, Graduate School of Engineering
Department of Mechanical Engineering, School of Engineering
In our laboratory, we are working on improving the performance and efficiency of hydraulic machinery as a component of infrastructure like pumps and hydroturbines, and on understanding complex fluid flow phenomena including liquid-vapor phase change that occurs in such hydraulic machinery, i.e., cavitation, in which bubbles are repeatedly generated and disappeared, from macroscopic to microscopic point of view. While SDGs are goals shared by all humankind, one of the most important issues is the improvement of the efficiency of hydraulic machines since they play a leading role in energy conversion between the machines and the fluids. Therefore, we are conducting studies on improving efficiency and reliability based on the clarification of the complex flow phenomena in the machines, mainly focusing on high-performance pumps used in power plants, high speed fuel pumps, and small hydroturbines that can be operated in agricultural and industrial waterways. In addition, cavitation tends to occur when the performance of hydraulic machinery is upgraded, and it is equally important to accurately predict this phenomenon at the design stage. Based on the recognition that cavitation is essentially composed of various large and small bubbles, we are investigating not only the macroscopic but also the microscopic behavior such as the initial stage of bubble generation and the process of collapse of a bubble, finally aiming the accurate prediction of this phenomenon.