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TOMOAKI UTSUNOMIYA Last modified date:2023.11.22



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Homepage
https://kyushu-u.elsevierpure.com/en/persons/tomoaki-utsunomiya
 Reseacher Profiling Tool Kyushu University Pure
Phone
092-802-3447
Fax
092-802-3368
Academic Degree
Doctor of Engineering
Field of Specialization
Ocean Energy Resources Engineering
ORCID(Open Researcher and Contributor ID)
0000-0003-2081-7547
Outline Activities
Research on fundamental technology for utilization of ocean renewable energy
Research
Research Interests
  • Research on fundamental technology for utilization of ocean renewable energy
    keyword : ocean renewable energy, floating wind turbine, floating offshore wind power generation, OTEC
    2014.04~2033.03.
Academic Activities
Books
1. Atanasios Kolios, Kyong-Hwan Kim, Chen Hsing Cheng, Elif Oguz, Pablo Morato, Freeman Ralph, Chuang Fang, Chunyan Ji, Marc Le Boulluec, Thomas Choisnet, Luca Greco, Tomoaki Utsunomiya, Kourosh Rezanejad, Charles Rawson, Jose Miguel Rodrigues, Proceedings of the 21st International Ship and Offshore Structures Congress (ISSC2022), Report of Committee V.4 Offshore Renewable Energy, ISSC, 2022.09.
2. Tomoaki Utsunomiya, Iku Sato, Takashi Shiraishi, Floating Offshore Wind Turbines in Goto Islands, Nagasaki, Japan, Springer, 10.1007/978-981-13-8743-2_20, 359-372, 2020.01, Offshore wind energy resources in Japanese EEZ are now considered to be huge. In order to utilize the huge amount of energy located in relatively deep water areas, Ministry of the Environment, Japan funded a demonstration project on floating offshore wind turbine (FOWT). In the project, two FOWTs have been installed. The first FOWT mounted a 100 kW wind turbine of downwind type, and the length dimensions are almost half of the second FOWT. The second FOWT mounted a 2 MW wind turbine of downwind type, and was referred to as the full-scale model. The FOWTs consist of PC-steel hybrid spar which is cost-effective and are moored by three mooring chains. The half-scale model was installed at the site (Kabashima, Goto Islands, Nagasaki prefecture, Japan) on 11 June 2012. The half-scale model was attacked by a very severe typhoon Sanba (1216). The behavior of the half-scale model during the typhoon attack was recorded, and compared with the computer simulations, indicating the validity of the design method. After a successful demonstration test of the half-scale model, the full-scale model was designed, constructed and installed at the same site. The demonstration test for the full-scale model was also successful. After completion of the demonstration project, the full-scale model was moved to a different site off Fukue island, where future expansion as a floating wind farm is planned. There, the full-scale model is operating as a commercial floating wind turbine, providing valuable data and experience for operation and maintenance toward commercial-scale floating wind farms..
3. Zhen Gao, Harry B. Bingham, David Ingram, Athanasios Kolios, Debabrata Karmakar, Tomoaki Utsunomiya, Ivan Catipovic, Giuseppina Colicchio, Jose Miguel Rodrigues, Frank Adam, Dale G. Karr, Chuang Fang, Hyun-Kyoung Shin, Johan Slatte, Chunyan Ji, Wanan Sheng, Pengfei Liu, Lyudmil Stoev, Proceedings of the 20th International Ship and Offshore Structures Congress 2018 9-13 September 2018, Liege - Belgium & Amsterdam - The Netherlands, Report of Committee V.4 Offshore Renewable Energy, ISSC, 2018.09.
4. D. Roddier, C. Cermelli, J. Weinstein, E. Byklum, M. Atcheson, T. Utsunomiya, J. Jorde, E. Borgen, State-of-the-Art, in "Floating Offshore Wind Energy - The Next Generation of Wind Energy", Springer International Publishing, 2016.09.
5. C. M. WANG, E. WATANABE, T. UTSUNOMIYA, Very Large Floating Structures (Spon Research), Taylor and Francis, 2007.09.
Papers
1. Koji Tanaka, Atsuhiro Iwamoto, Tomoaki Utsunomiya, Comparison of dynamic response of a 2-MW hybrid-spar floating offshore wind turbine during power production using full-scale field data, Grand Renewable Energy 2022 International Conference, https://doi.org/10.24752/gre.2.0_42, 2022.12.
2. Yogie Muhammad Lutfi, Ristiyanto Adiputra, Aditya Rio Prabowo, Tomoaki Utsunomiya, Erwandi Erwandi, Nurul Muhayat, Assessment of the stiffened panel performance in the OTEC seawater tank design: Parametric study and sensitivity analysis, Theoretical and Applied Mechanics Letters, https://doi.org/10.1016/j.taml.2023.100452, 13, 2023.04.
3. Ryoya Hisamatsu, Tomoaki Utsunomiya, Free vibration and stability of a fully submerged pipe aspirating water: An experiment and new physical insights, Journal of Fluids and Structures, https://doi.org/10.1016/j.jfluidstructs.2022.103789, 116, 2023.01, Dynamic stability due to internal axial flow is a considerable problem for a pipe conveying fluid such as deep seawater intaking for an Ocean Thermal Energy Conversion (OTEC) plant. However, there has been much ambiguity about its dynamics, and this raises a question about whether such an aspirating pipe submerged in water flutters or not. Therefore, the objective of this paper is to provide an experiment to take a new look at the dynamics of pipe aspirating fluid (water). The experimental apparatus is constructed to eliminate expected disturbances, and we measure free damped vibrations of a submerged 4 m length pipe with internal flow. As a result, we observe the nonlinear and non-planar behavior, however, the pipe converges to the zero point and remains stable at a maximum velocity of 1.66 m/s. Subsequently, we review existing theoretical models, and present a comparison with the results from the tank experiment. In addition, we provide a new model of the inlet flow field, which plays an important role on stability, considering the flow separation and jet formed inside of the pipe entrance. This equation is solved by FEM for time integration and eigenvalue analysis, and the results seem to reproduce the experimental natural period and amplitude of the free vibration with internal flow. The model also suggests that an aspirating pipe submerged in water does not flutter up to the maximum flow velocity attainable in the experiment..
4. Ryoya Hisamatsu, Tomoaki Utsunomiya, Dynamics of a cold water intaking pipe subject to internal flow and motion excitation, ASME 2023 42nd International Conference on Ocean, Offshore and Arctic Engineering, 2023.06.
5. Ryoya Hisamatsu, Ristiyanto Adiputra, Tomoaki Utsunomiya, Experimental Study on Dynamic Characteristics of Fluid‑conveying Pipe for OTEC, ASME 2022 41st International Conference on Ocean, Offshore and Arctic Engineering, https://doi.org/10.1115/OMAE2022‑78136, 2022.10.
6. Ristiyanto Adiputra, Tomoaki Utsunomiya, Finite Element Modelling of Ocean Thermal Energy Conversion (OTEC) Cold Water Pipe (CWP), ASME 2022 41st International Conference on Ocean, Offshore and Arctic Engineering, https://doi.org/10.1115/OMAE2022‑78135, 2022.10.
7. Ryoya Hisamatsu, Tomoaki Utsunomiya, Coupled response characteristics of cold water pipe and moored ship for floating OTEC plant, Applied Ocean Research, https://doi.org/10.1016/j.apor.2022.103151, 123, 2022.04, [URL], A floating Ocean Thermal Energy Conversion (OTEC) plant requires a large-diameter Cold Water Pipe (CWP) to be attached to a floating structure. For the design of the mooring system and the CWP, a coupled analysis of a floating body, mooring system and CWP should be employed due to the huge mass of the internal fluid in the CWP. The aim of this paper is to construct a simplified coupled response model to facilitate the preliminary stage of the design. The equations of equilibrium and motion are derived based on modeling as a two-dimensional floating body and an elastic pendulum. In order to verify the applicability for a practical design and limitation of the present model, a 100 MW ship-shaped platform, a spread mooring system and a CWP with an inner diameter of 12 m and a length of 800 m are configured. The results of the extreme analysis in the frequency domain with equivalent linearization of drag force by using the present model agree well with the time domain coupled analysis using OrcaFlex. Subsequently, the influence of the design parameters for CWP to the coupled responses is also clarified by a parametric study combining the bending stiffness, the linear density and the boundary conditions. The proposed model will facilitate the preliminary study with a large number of design trials, and a comprehension of the results of numerical simulations and model experiments..
8. Ryoya Hisamatsu, Tomoaki Utsunomiya, Simplified Formulation of Coupled System Between Moored Ship and Elastic Pipe for OTEC Plantship, ASME 2021 40th International Conference on Ocean, Offshore and Arctic Engineering, https://doi.org/10.1115/OMAE2021-62122, 2021.10, A floating Ocean Thermal Energy Conversion (OTEC) plant requires a large-diameter Cold Water Pipe (CWP) to be attached to a floating structure. For the design of the mooring system and the CWP, a coupled analysis of a floating body, mooring system and CWP should be employed due to the huge mass of the internal fluid in the CWP. The aim of this paper is to construct a simplified coupled response model to facilitate the preliminary stage of the design. The equations of equilibrium and motion are derived based on modeling as a two-dimensional floating body and an elastic pendulum. In order to verify the applicability for a practical design and limitation of the present model, a 100 MW ship-shaped platform, a spread mooring system and a CWP with an inner diameter of 12 m and a length of 800 m are configured. The results of the extreme analysis in the frequency domain with equivalent linearization of drag force by using the present model agree well with the time domain coupled analysis using OrcaFlex. Subsequently, the influence of the design parameters for CWP to the coupled responses is also clarified by a parametric study combining the bending stiffness, the linear density and the boundary conditions. The proposed model will facilitate the preliminary study with a large number of design trials, and a comprehension of the results of numerical simulations and model experiments..
9. Takaaki Takeuchi, Tomoaki Utsunomiya, Koji Gotoh, Iku Sato, Development of Simplified Wear Estimation Method Considering Rolling Motion Between Mooring Chain Links for Floating Structures, ASME 2021 40th International Conference on Ocean, Offshore and Arctic Engineering, https://doi.org/10.1115/OMAE2021-62574, 2021.10.
10. , [URL].
11. Takeuchi, T., Utsunomiya, T., Gotoh, K., & Sato, I., Development of interlink wear estimation method for mooring chain of floating structures: Validation and new approach using three-dimensional contact response, Marine Structures, https://doi.org/10.1016/j.marstruc.2020.102927, 77, 2021.05, [URL], Long-term operation of mooring systems is one of the challenging issues of floating structures such as floating offshore wind turbines (FOWTs). For integrity assessment, fatigue and its affecting factors have generated considerable recent research interest as the occurrence of a large number of mooring chain failures at a high rate has been reported. By contrast, only few studies on the effect of nonuniform volume loss of mooring chain links due to wear can be found because of difficulties to estimate wear amounts quantitatively. Considering this issue, in this paper, validation of the quantitative interlink wear estimation method is investigated by applying to a spar-type floating structure. Firstly, the method is presented which consists of the material test, derivation of an interlink wear estimation formula with FE analysis, and calculation of mooring chain response with coupled dynamic analysis using a mass-spring model. To improve insufficient accuracy due to the mass-spring model around a clump weight and the touchdown point, the method is further modified by using a 3-D rigid-body link model. The estimation results and comparison show that the modified method distinguishing between rolling and sliding can calculate the interlink wear amount closer to the chain diameter measurements and more reasonable than the method using the conventional mass-spring model..
12. Ristiyanto Adiputra, Tomoaki Utsunomiya, Linear vs non-linear analysis on self-induced vibration of OTEC cold water pipe due to internal flow, Applied Ocean Research, https://doi.org/10.1016/j.apor.2021.102610, 110, 2021.03, [URL], This paper presents analytical and numerical analyses on self-induced vibration of Ocean Thermal Energy Conversion (OTEC) Cold Water Pipe (CWP) for a 100 MW-net OTEC power plant. The CWP is described as a vertically-hanged, top-tensioned riser subjected to internal flow effect (IFE) and ambient fluid effects (added mass and drag force). In the analytical analysis, two definitions of the drag force equation in the frequency-domain term and time-domain term are considered yielding a linear differential equation and a non-linear differential equation. The stability is assessed by discretizing the equations using Frobenius method and Galerkin Method and then plotting its eigenfrequencies or its eigenvalues in an Argand diagram. Separately, a fully-coupled fluid-structure interaction is carried out in a numerical simulation for particular cases. The scantlings of the riser are chosen from the available size of Fiber Reinforced Plastic (FRP) pipe in a manufacturer and varied accordingly for future production capacity development. The riser is pinned at the top and mounted at the bottom. Results indicate that the predicted critical velocity in the time domain is averagely 20% higher compared to the frequency domain. The effect of the clump weight on the critical velocity is more significant for light material compared with relatively high-density material..
13. Kakuya, H., Yoshida, S., Sato, I. & Utsunomiya, T., A study on the platform-pitching vibration of floating offshore wind turbines based on classical control theory, Wind Engineering, https://doi.org/10.1177/0309524X19862761, 44, 6, 610-630, 2020.10.
14. Kakuya, H., Yoshida, S., Sato, I. & Utsunomiya, T., Proposal for a lower limit control of a generator’s torque based on the nacelle wind speed and demonstration results using a full-scale spar-type floating offshore wind turbine, Wind Engineering, https://doi.org/10.1177/0309524X19862754, 44, 6, 645-660, 2020.10.
15. Takaaki Takeuchi, Tomoaki Utsunomiya, Koji Gotoh, Iku Sato, Quantitative wear estimation for floating structures by using 3-D geometry of mooring chain, ASME 2020 39th International Conference on Ocean, Offshore and Arctic Engineering, OMAE2020, https://doi.org/10.1115/OMAE2020-18409, OMAE2020-18409, 2020.08, [URL].
16. Koji Tanaka, Iku Sato, Tomoaki Utsunomiya, Hiromu Kakuya, Validation of dynamic response of a 2-MW hybrid-spar floating wind turbine during typhoon using full-scale field data, Ocean Engineering, 10.1016/j.oceaneng.2020.108262, 218, 2020.10, Accurate estimation of the dynamic behavior of Floating Offshore Wind Turbines (FOWTs) under typhoon environment is essential to design and install FOWTs in a prone area of typhoons such as around Japan. Up to now, extensive efforts for development of design tools for FOWTs have been made, and nowadays several design tools are available. Needless to say, it is of utmost importance that the engineering design tools have been verified and validated for the real physical phenomena before being applied to real designs/projects with confidence. Much efforts have thus been made as code-to-code comparisons and by validations using model test data. Validations of the design tools using full-scale field data for FOWTs have also been made, but available open literatures are quite limited, particularly for design-driving extreme cases. In this paper, we describe the analysis of the dynamic response of a 2-MW spar-type FOWT at the time of typhoon attack in the actual sea area. The central atmospheric pressure of the typhoon at the closest time was 965 hPa, the maximum instantaneous wind speed at the hub height was 52.2 m/s, and the maximum significant wave height was 6.9 m. The dynamic responses under the typhoon environment are numerically simulated by using the time-series records of the wind speed, the wind direction, the wave height, the wave direction, the current speed, and the current direction which were acquired during the typhoon passing through close to the FOWT. Then the simulated motion responses are compared with the measured motion responses for the same durations. By the comparisons, the numerical simulation tool which was used for the design of the FOWT has been partially validated. It has also been confirmed that the spatial coherence of the wind speed has a significant effect for the platform motions, particularly for yaw motion..
17. Ristiyanto Adiputra, Tomoaki Utsunomiya, Stability based approach to design cold-water pipe (CWP) for ocean thermal energy conversion (OTEC), Applied Ocean Research, 10.1016/j.apor.2019.101921, 92, 2019.11, Cold-water pipe (CWP) is a novel, most-challenging component of Ocean Thermal Energy Conversion (OTEC) floating structure which is installed to transport the deep seawater to the board. For commercial scale, the transported seawater flow rate will be in the order of 10^2 m^3/s. This large amount of internal flow may trigger instability which leads to the failure of CWP. Considering this issue, the present paper aims to design commercial-scale OTEC CWP focusing on the effects of internal flow to the stability of the pipe. The design analysis is deliberated to select the pipe material, top joint configuration (fixed, flexible, pinned) and bottom supporting system (with and without clump weight). Initially, the analytical solution is built by taking into account the components of the pipe dynamics. Separately, a fully coupled fluid-structure interaction analysis between the pipe and the ambient fluid is carried out using ANSYS interface. Using scale models, the results obtained from the analytical solution are compared with the ones from numerical analysis to examine the feasibility of the analytical solution. After being verified, the analytical solution is used to observe the dynamic behavior of the CWP for 100 MW-net OTEC power plant in the full-scale model. The results yield conclusions that pinned connection at the top joint is preferable to decrease the applied stress, clump weight installation is necessary to reduce the motion displacement and Fiber Reinforced Plastic (FRP) is the most suitable material among the examined materials..
18. Ristiyanto Adiputra, Tomoaki Utsunomiya, Jaswar Koto, Takeshi Yasunaga, Yasuyuki Ikegami, Preliminary design of a 100 MW-net ocean thermal energy conversion (OTEC) power plant study case: Mentawai island, Indonesia, Journal of Marine Science and Technology, https://doi.org/10.1007/s00773-019-00630-7, 2019.02, Ocean thermal energy conversion is one of the promising renewable energy resources yet relatively unexplored due to its high capital cost for being utilized in commercial scale. In the aim to reduce the capital cost, this paper introduces a concept design of the floating structure from a converted oil tanker ship. To propose the design process, the general principles of designing a converted tanker FPSO is adapted and then modified to deal with ocean thermal energy conversion (OTEC) characteristic. In the design process, the arrangement of the OTEC layout is carried out by constraint satisfaction method and the prospective floating structure size is varied using Monte Carlo simulation. The variables in the design process consist of the velocities of cold water and warm water transport, the size of the plantship, and the location of the OTEC equipment to the seawater tank. Constraints are introduced as allowable border to determine the acceptability for particular case including the provided space and buoyancy, and the net power output estimation. The results show that the ‘typical’ size of a Suezmax oil tanker ship is the optimum one for the plantship with the velocity of the water transport of 2–3 m/s. The general arrangement is also conceptualized in this paper..
19. Utsunomiya, T., Sato, I., Kobayashi, O., Shiraishi, T., Harada, T., Numerical Modeling and Analysis of a Hybrid-Spar Floating Wind Turbine, Journal of Offshore Mechanics and Arctic Engineering, ASME, 10.1115/1.4041994, 141, 3, 031903-1-031903-5, 2019.01.
20. Jian Dai, Chien Ming Wang, Tomoaki Utsunomiya, Wenhui Duan, Review of recent research and developments on floating breakwaters, Ocean Engineering, https://doi.org/10.1016/j.oceaneng.2018.03.083, 158, 132-151, 2018.06.
21. Koji Gotoh, Koji Murakami, Masataka Nakagawa and Tomoaki Utsunomiya, Wear Performance of the Mooring Chain Used in Floating Wind Turbines, Proceedings of the ASME 2017 36th International Conference on Ocean, Offshore and Arctic Engineering, 10.1115/OMAE2017-62195, 2017.06.
22. Tomoaki Utsunomiya, Kinji Sekita, Katsutoshi Kita and Iku Sato, Demonstration Test for Using Suction Anchor and Polyester Rope in Floating Offshore Wind Turbine, Proceedings of the ASME 2017 36th International Conference on Ocean, Offshore and Arctic Engineering, 10.1115/OMAE2017-62197, 2017.06.
23. Tomoaki Utsunomiya, Iku Sato, Osamu Kobayashi, Takashi Shiraishi and Takashi Harada, Numerical Modelling and Analysis of a Hybrid-Spar Floating Wind Turbine, Proceedings of the ASME 2017 36th International Conference on Ocean, Offshore and Arctic Engineering, 10.1115/OMAE2017-62578, 2017.06.
24. T. UTSUNOMIYA, I. SATO, O. KOBAYASHI, T. SHIRAISHI, T. HARADA, Design and Installation of a Hybrid-Spar Floating Wind Turbine Platform, Proceedings of the ASME 2015 34th International Conference on Ocean, Offshore and Arctic Engineering, 10.1115/OMAE2015-41544, 2015.05.
25. T. UTSUNOMIYA, S. YOSHIDA, H. OOKUBO, I. SATO, S. ISHIDA, Dynamic analysis of a floating offshore wind turbine under extreme environmental conditions, Journal of Offshore Mechanics and Arctic Engineering, ASME, 10.1115/1.4025872, 136, 2, 020904, 2014.03, [URL].
26. K. SHIBANUMA, T. UTSUNOMIYA, S. AIHARA, An explicit application of partition of unity approach to XFEM approximation for precise reproduction of a priori knowledge of solution, International Journal for Numerical Methods in Engineering, 10.1002/nme.4593, 97, 8, 551-581, 2014.02.
27. T. UTSUNOMIYA, H. MATSUKUMA, S. MINOURA, K. KO, H. HAMAMURA, O. KOBAYASHI, I. SATO, Y. NOMOTO, K. YASUI, At-sea experiment of a hybrid spar for floating offshore wind turbine using 1/10-scale model, Journal of Offshore Mechanics and Arctic Engineering, ASME, 10.1115/1.4024148, 135, 3, 034503, 2013.08.
28. Ishida, S., Kokubun, K., Nimura, T., Utsunomiya, T., Sato, I., Yoshida, S., AT-SEA EXPERIMENT OF A HYBRID SPAR TYPE OFFSHORE WIND TURBINE, PROCEEDINGS OF THE ASME 32ND INTERNATIONAL CONFERENCE ON OCEAN, OFFSHORE AND ARCTIC ENGINEERING - 2013 - VOL 8, 10.1115/OMAE2013-10655, V008T09A035, 2013.06.
29. Utsunomiya, T., Sato, I., Yoshida, S., Ookubo, H., Ishida, S, DYNAMIC RESPONSE ANALYSIS OF A FLOATING OFFSHORE WIND TURBINE DURING SEVERE TYPHOON EVENT, PROCEEDINGS OF THE ASME 32ND INTERNATIONAL CONFERENCE ON OCEAN, OFFSHORE AND ARCTIC ENGINEERING - 2013 - VOL 8, 10.1115/OMAE2013-10618, V008T09A032, 2013.06.
30. Utsunomiya, T., Yoshida, S., Ookubo, H., Sato, I., Ishida, S., DYNAMIC ANALYSIS OF A FLOATING OFFSHORE WIND TURBINE UNDER EXTREME ENVIRONMENTAL CONDITIONS, PROCEEDINGS OF THE ASME 31ST INTERNATIONAL CONFERENCE ON OCEAN, OFFSHORE AND ARTIC ENGINEERING, VOL 7, 10.1115/OMAE2012-83985, 559-568, 2012.07.
31. Kokubun, K., Ishida, S., Nimura, T., Chujo, T., Yoshida, S., Utsunomiya, T., MODEL EXPERIMENT OF A SPAR TYPE OFFSHORE WIND TURBINE IN STORM CONDITION, PROCEEDINGS OF THE ASME 31ST INTERNATIONAL CONFERENCE ON OCEAN, OFFSHORE AND ARTIC ENGINEERING, VOL 7, 10.1115/OMAE2012-83993, 569-575, 2012.06.
32. K. SHIBANUMA, T. UTSUNOMIYA, Evaluation on reproduction of priori knowledge in XFEM, Finite Elements in Analysis and Design, 10.1016/j.finel.2010.11.007, 47, 4, 424-433, 2011.04.
33. C. M. WANG, Z. Y. TAY, K. TAKAGI, T. UTSUNOMIYA, Literature review of methods for mitigating hydroelastic response of VLFS under wave action, Applied Mechanics Reviews, 10.1115/1.4001690, 63, 3, 030802, 2010.06.
34. E. P. BANGUN, C. M. WANG, T. UTSUNOMIYA, Hydrodynamic forces on a rolling barge with bilge keels, Applied Ocean Research, 10.1016/j.apor.2009.10.008, 32, 2, 219-232, 2010.04.
35. K. SHIBANUMA, T. UTSUNOMIYA, Reformulation of XFEM based on PUFEM for solving problem caused by blending elements, Finite Elements in Analysis and Design, 45, 11, 806-816, 2009.09.
36. Z. Y. TAY, C. M. WANG, T. UTSUNOMIYA, Hydroelastic responses and interactions of floating fuel storage modules placed side-by-side with floating breakwaters, Marine Structures, 22, 3, 633-658, 2009.07.
37. C. RIVEROS, T. UTSUNOMIYA, K. MAEDA, K. ITOH, Dynamic response of oscillating flexible risers under lock-in events, International Journal of Offshore and Polar Engineering, 19, 1, 23-30, 2009.03.
38. H. MATSUKUMA, T. UTSUNOMIYA, Motion analysis of a floating offshore wind turbine considering rotor-rotation, The IES Journal Part A: Civil and Structural Engineering, 1, 4, 268-279, 2008.10.
39. D. C. PHAM, C. M. WANG, T. UTSUNOMIYA, Hydroelastic analysis of pontoon-type circular VLFS with an attached submerged plate, Applied Ocean Research, 30, 4, 287-296, 2008.10.
40. C. RIVEROS, T. UTSUNOMIYA, K. MAEDA, K. ITOH, Damage detection in flexible risers using statistical pattern recognition techniques, International Journal of Offshore and Polar Engineering, 18, 1, 35-42, 2008.03.
41. T. UTSUNOMIYA, T. OKAFUJI, Wave response analysis of a VLFS by accelerated Green's function method in infinite water depth, International Journal of Offshore and Polar Engineering, 17, 1, 30-38, 2007.03.
42. C. M. WANG, W. X. WU, C. SHU, T. UTSUNOMIYA, LSFD method for accurate vibration modes and modal stress-resultants of freely vibrating plates that model VLFS, Computers and Structures, 84, 31-32, 2329-2339, 2006.12.
43. T. UTSUNOMIYA, E. WATANABE, Fast multipole method for wave diffraction/radiation problems and its applications to VLFS, International Journal of Offshore and Polar Engineering, 16, 4, 253-260, 2006.12.
44. S. KIDA, T. UTSUNOMIYA, Analysis of the slowly varying drift force on a very large floating structure in multidirectional random seas, Journal of Marine Science and Technology, 11, 4, 229-236, 2006.12.
45. E. WATANABE, T. UTSUNOMIYA, C. M. WANG, L. T. T. HANG, Benchmark hydroelastic responses of a circular VLFS under wave action, Engineering Structures, 28, 3, 423-430, 2006.02.
46. N. MAKIHATA, T. UTSUNOMIYA, E. WATANABE, Effectiveness of GMRES-DR and OSP-ILUC for wave diffraction analysis of a very large floating structure (VLFS), Engineering Analysis with Boundary Elements, 30, 1, 49-58, 2006.01.
47. C. M. WANG, Y. XIANG, E. WATANABE, T. UTSUNOMIYA, Mode shapes and stress-resultants of circular Mindlin plates with free edges, Journal of Sound and Vibration, 276, 3-5, 511-525, 2004.09.
48. K.-L. PARK, E. WATANABE, T. UTSUNOMIYA, Development of 3d elastodynamic infinite elements for soil-structure interaction problems, International Journal of Structural Stability and Dynamics, 4, 3, 423-441, 2004.09.
49. C. MACHIMDAMRONG, E. WATANABE, T. UTSUNOMIYA, Shear buckling of corrugated plates with edges elastically restrained against rotation, International Journal of Structural Stability and Dynamics, 4, 1, 89-104, 2004.03.
50. E. WATANABE, T. UTSUNOMIYA, C. M. WANG, Hydroelastic analysis of pontoon-type VLFS: a literature survey, Engineering Structures, 26, 2, 245-256, 2004.01.
51. E. WATANABE, T. UTSUNOMIYA, M. KURAMOTO, H. OHTA, T. TORII, N. HAYASHI, Wave response analysis of VLFS with an attached submerged plate, International Journal of Offshore and Polar Engineering, 13, 2, 190-197, 2003.09.
52. E. WATANABE, T. UTSUNOMIYA, Analysis and design of floating bridges, Progress in Structural Engineering and Materials, 5, 3, 127-144, 2003.09.
53. C. M. WANG, Y. XIANG, T. UTSUNOMIYA, E. WATANABE, Evaluation of modal stress resultants in freely vibrating plates, International Journal of Solids and Structures, 38, 36-37, 6525-6558, 2001.09.
54. T. UTSUNOMIYA, R. EATOCK TAYLOR, Resonances in wave diffraction/radiation for arrays of elastically connected cylinders, Journal of Fluids and Structures, 14, 7, 1035-1051, 2000.10.
55. E. WATANABE, T. UTSUNOMIYA, A. KUBOTA, Analysis of wave-drift damping of a VLFS with shallow draft, Marine Structures, 13, 4-5, 383-397, 2000.07.
56. T. UTSUNOMIYA, R. EATOCK TAYLOR, Trapped modes around a row of circular cylinders in a channel, Journal of Fluid Mechanics, 386, 259-279, 1999.05.
57. C. WU, E. WATANABE, T. UTSUNOMIYA, An eigenfunction expansion-matching method for analyzing the wave-induced responses of an elastic floating plate, Applied Ocean Research, 17, 5, 301-310, 1995.10.
58. T. UTSUNOMIYA, H. NISHIZAWA, K. KANETA, Biaxial stress measurement using a magnetic probe based on the law of approach to saturation magnetization, NDT&E International, 24, 2, 91-94, 1991.04.
59. T. UTSUNOMIYA, H. NISHIZAWA, K. KANETA, Effect of stress on the law of approach to saturation magnetization in carbon steels, IEEE Transactions on Magnetics, 27, 3, 3420-3425, 1991.05.
Presentations
1. Tomoaki Utsunomiya, Iku Sato, Takashi Shiraishi, Floating Offshore Wind Turbines in Goto Islands, Nagasaki, Japan, The International Conference on Sustainable Civil Engineering and Architecture (ICSCEA) 2019, 2019.10.
2. Tomoaki Utsunomiya, Iku Sato, Takashi Shiraishi, FLOATING OFFSHORE WIND TURBINES IN GOTO ISLANDS, NAGASAKI, JAPAN, World Conference on Floating Solutions 2019, 2019.04.
Membership in Academic Society
  • The Japan Society of Naval Architects and Ocean Engineers
  • Japan Wind Energy Association
  • Ocean Energy Association - Japan
  • Japan Society of Civil Engineers