I aim for clarifying complex phenomena such as multi-scale and multi-phase phenomena and improving the control technology.
① Research on air-blast atomization of a liquid sheet in gas turbine (2012~)
② Research on steam turbine for geothermal power generation (2019~)

Employment

Education

Research on air-blast atomization of a liquid sheet in gas turbine

The following figure shows a high-speed image of a planar liquid sheet atomization process using a planar air-blast atomizer. The liquid film injected from the injector is deformed and atomized by the complex interactions between the liquid and surrounding gas flows.
In primary break-up of the liquid sheet, ligaments and bags are generated. ligaments break-up produces coarse droplets, and bag break-up produces small droplets. In secondary break-up, coarse droplets are atomized, which result in smaller droplets. The prediction of atomization characteristics requires several experiments yet, even though this phenomenon looks like simple.
Initial deformation of the liquid sheet affects on primary break-up, and that affects on secondary break-up. However, the interaction of each break-up process has not been studied sufficiently. Therefore, I focus on the interaction between initial deformation, primary and secondary break-up in addition to the mechanism of the individual processes. I aim for making clear the atomization process of the liquid sheet induced by air-flows and improve the control technology dramatically.

Research on steam turbine for geothermal power generation

Geothermal power generation which can generates electricity throughout the day receives a lot of attention as one of hopeful renewable energy. Geothermal power generation generates electricity using steam turbines. Magma heats underground water, which produces steam. Hence, the operating condition of turbines is not good because the steam is highly corrosive.
While the improvement of durability and efficiency is significant for turbines, it is unclear what is happening inside the turbine. Therefore, it is necessary to know exactly the phenomena inside the turbine. I aim for clarifing the generation mechanism of coarse droplets and optimizing the shape and position of machines for removing large droplets by focusing on the coarse droplets, which influence on the durability and efficiency of turbine.

Original Publications (Peer-Reviewed)

• Ippei Oshima, Akira Sou: Numerical Simulation of Liquid Sheet Deformation Caused by Air Flow, Transactions of the Japan Society for Aeronautical and Space Sciences, Aerospace Technology Japan Volume 16, Issue 4, Page 319-327, 2018.
• Ippei Oshima, Akira Sou: Longitudinal Oscillation of a Liquid Sheet by Parallel Air Flows, International Journal of Multiphase Flow, Volume 110, Page 179-188, 2019.