2023 Fiscal Year Final Research Report

Development of simultaneous multipoint measurement system of ship side water level applicable to actual ship

Research Project

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Project/Area Number	19K04867
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Review Section	Basic Section 24020:Marine engineering-related
Research Institution	National Institute of Maritime, Port and Aviation Technology
Principal Investigator	Ikemoto Yoshinori 国立研究開発法人海上・港湾・航空技術研究所, 海上技術安全研究所, 研究員 (80358407)
Project Period (FY)	2019-04-01 – 2024-03-31
Keywords	電気抵抗式水位計 / TDR / Time Domain Reflectmetry / 多点同時計測 / 波高計 / 水位計 / 波高 / 水位
Outline of Final Research Achievements	Measuring the water level distribution around ship hulls and marine structures is one of the important elements of monitoring their condition. In this study, we devised a method of measurement based on electrical resistance, forming an array of electrodes on the side surface of the model ship itself to serve as a sensor for simultaneous multi-point measurement of water level changes due to wave generation, etc. We also devised a measurement method using Electric Resistance and Time Domain Reflectometry. For each, we attached a simultaneous multi-point water level meter to the side of the model ship and conducted wave heignt measurement trials in a wave-making tank. In the electrical resistance-based measurement, we confirmed that the encounter wave height inputted matched well with the measurement by the sensor on the model ship. We also conducted experiments under the same conditions with the TDR method, but we did not reach the point of establishing a dynamic analysis algorithm.
Free Research Field	船舶海洋工学
Academic Significance and Societal Importance of the Research Achievements	従来、船体側面に生じる水位変化による造波抵抗の推算には写真撮影やビデオカメラ画像による解析が用いられてきた。しかしながら、光学的な計測ではカメラから計測対象までの間に不要な波が画角に入るのが避けられない課題があった。またセンサを水に沈めて計測する手法ではそれ自身が波を起こすため、船体側面の同時多点水位計測は困難であった。本研究ではに0.1mm以下のテープ状導電性材料を短冊状に並べてセンサとして用いた。このセンサで時空間的に船体側面の波形を捉えることを可能なことを確かめた。浮体などの表面に生じている水位を容易に捉えられるため、浮体周りの計算流体力学などの解析精度向上に役立つものと期待される。