Kyushu University Academic Staff Educational and Research Activities Database
List of Papers
Umehara Yutaro Last modified dateļ¼š2024.04.05

Assistant Professor / Thermal engineering department / Department of Mechanical Engineering / Faculty of Engineering


Papers
1. Xuesong Wei, Takumi Kakimoto, Yutaro Umehara, Hironori Nakajima, Kohei Ito, Hiromitsu Inagaki, Shoji Mori, Improvement of the critical current density of alkaline water electrolysis based on the hydrodynamic similarity between boiling and water electrolysis, International Journal of Heat and Mass Transfer, 10.1016/j.ijheatmasstransfer.2023.124420, 214, 124420-124420, 2023.11.
2. Yutaro UMEHARA, Tomio OKAWA, Phenomenological modeling of quenching during falling liquid film cooling of high-temperature wall, Applied Thermal Engineering, 10.1016/j.applthermaleng.2023.120210, 2023.05.
3. Yutaro Umehara, Keisuke Yamagata, Tomio Okawa, Spatial distribution of heat transfer coefficient in the vicinity of wetting front during falling liquid film cooling of a vertical hot wall, INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, 10.1016/j.ijheatmasstransfer.2021.122422, 185, 2022.04, Spatial distribution of the heat transfer coefficient (HTC) in the vicinity of the wetting front is of crucial importance in predicting the wetting velocity during liquid film cooling of a high-temperature solid surface. However, mainly due to the lack of experimental data, no sufficiently reliable model has been developed so far for the HTC distribution in this fundamental thermal-hydraulic situation. In the present work, experiments using a high-speed infra-red camera were carried out to measure the transient of wall temperature distribution during wetting of a high-temperature vertical wall with a falling liquid film. Based on the HTC distributions calculated from the measured temperature data, dimensionless correlations were developed for the HTC distribution near the wetting front. It was confirmed that the propagation velocities of the wetting front (wetting velocity) calculated using the proposed correlations agree with the experimental data accumulated in this work well. (c) 2021 Elsevier Ltd. All rights reserved..
4. Tomio Okawa, Keisuke Yamagata, Yutaro Umehara, Measurement of heat transfer coefficient profile during quenching of a vertical hot wall with a falling liquid film, NUCLEAR ENGINEERING AND DESIGN, 10.1016/j.nucengdes.2020.110629, 363, 2020.07.