Faculty of Engineering, Division of Systems Research

Job Title

Associate Professor

Research Fields, Keywords

Ship, Flying Boat, Submergible Ship, Wave-Buoy

Mail Address

E-mail address

Graduating School 【 display / non-display


    Yokohama National University   Faculty of Engineering   Graduated

Graduate School 【 display / non-display


    Yokohama National University    Doctor Course  Unfinished course


    Yokohama National University  Graduate School, Division of Engineering  Master Course  Completed

Degree 【 display / non-display

  • Doctor of Engineering -  Yokohama National University

  • Master of Engineering -  Yokohama National University

  • Bachelor of Engineering -  Yokohama National University

Field of expertise (Grants-in-aid for Scientific Research classification) 【 display / non-display

  • Naval and maritime engineering


Papers 【 display / non-display

  • Relative Motions of FLNG and LNG Carriers Arranged Side by Side and an Assessment of Their Operation

    Ryohei Yoshioka, Makoto Arai, Yoshiaki Hirakawa, Ning Ma, Kazuo Nishimoto

    One Petro ( SPE All rights reserved )  Vol.29 ( 2 )   2019.06

    Joint Work


  • Model experiments on the early detection and rudder stabilization of KCS parametric roll in head waves

    Liwei YuKo TaguchiAkagi KentaNing Ma,Yoshiaki Hirakawa

    Download PDF Journal of Marine Science and Technology   23 ( 1 )   141 - 163   2018.03  [Refereed]

    Joint Work


  • Offloading Operability Assessment for FLNG and LNG Carrier Arranged Side-by-side

    Yoshioka Ryohei, Arai Makoto, Hirakawa Yoshiaki, Ma Ning, Nishimoto Kazuo, Nakashima Akira

    Journal of the Japan Society of Naval Architects and Ocean Engineers ( The Japan Society of Naval Architects and Ocean Engineers )  27 ( 0 )   41 - 48   2018

    Joint Work

     View Summary

    <p>Floating LNG (FLNG) is a new type of offshore platform for production, liquefaction, storage and offloading of natural gas. The offloading process of liquefied natural gas (LNG) will use cryogenic loading arms between FLNG and LNG carrier in side-by-side arrangement. The loading arm has many track records in LNG terminals. However, environmental condition of offshore gas field is severer than those of ports. Unexpected large ship motions may occur and affect the offloading operability.</p><p>In this paper, the results of the operability assessment for the side-by-side offloading are presented. First, ship motions with liquid cargo in tanks and the free water surface motion in the narrow gap between two vessels are studied by numerical calculation in frequency domain and verified by model test. Then, the limits of environmental conditions for offloading operation are examined by the results of numerical calculation using the criteria for side-by-side offloading. Finally, offloading operability of FLNG and LNG carrier arranged side-by-side in Brazilian sea is evaluated.</p>

    DOI CiNii

  • Development of Mini-Buoy for Short Term Measurement of Ocean Wave

    Y. Hirakawa, T. Takayama, T. Hirayama, H. Susaki,

    OCEANS 2016 MTS/IEEE     2016.09

    Joint Work

     View Summary



  • Longitudinal Stability Augmentation of Seaplanes in Planing

    Keiichi Ito, Tom Dhaene, Yoshiaki Hirakawa, Tsugukiyo Hirayama, Tatsumi Sakurai

    Journal of Aircraft   53 ( 5 )   1332 - 1342   2016.09  [Refereed]

    Joint Work

     View Summary

    フロート付き水上機で問題となっている滑走時不安定現象(ポーポイジング)について、現象の再現及び不安定現象の抑制方法について数値計算・水槽実験の両面から検討した。 )

    Web of Science DOI

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Grant-in-Aid for Scientific Research 【 display / non-display

  • Grant-in-Aid for Young Scientists(B)

    Project Year: 2012.04  -  2015.03 

Presentations 【 display / non-display

  • Ocean Wave Measurements Utilizing Ultra-Small-Buoy

    8th PUL Meeting (Port-city University League)  2014.10  

  • R&D on New Stern Boat Deployment and Recovery System from Running Ship

    5th PUL Meeting (Port-city University League)  2011.11