Osaka Electro-Communication University Faculty Information Database >安永　健

Department of Mechanical Engineering

Takeshi YASUNAGA Takeshi　YASUNAGA

  • Specialized field
    Thermal Engineering (Organic Rankine Cycle, Ocean Thermal Energy Conversion, Seawater Desalination)
  • Research Interests
    Optimal design of power generation systems utilizing unused low-temperature heat sources, such as Ocean Thermal Energy Conversion (OTEC), geothermal water, and waste heat through Organic Rankine Cycle (ORC) systems
    Optimization of heat transfer surface geometry in plate heat exchangers
    Development of seawater desalination systems utilizing ocean thermal energy
  • Academic Background
  • Education
    Apr. 2005 - Mar. 2008　Ph.D, Science and Advanced Technology, Graduate School of Science and Engineering, Saga University
    Apr. 2003 - Mar. 2005 M.Eng., Mechanical Engineering, Graduate School of Science and Engineering, Saga University,
    Apr. 1999 - Mar. 2003　B.Eng., Energy Mechanical Engineering, Engineering, Doshisha University
  • Work Experience
    Apr. 2024 - Present　Associate Professor, Osaka Electro-Communication University
    Apr. 2023 - Mar. 2024　Associate Professor, Institute of Ocean Energy, Saga University
    Apr. 2015 - Mar. 2023　Assistant Professor, Institute of Ocean Energy, Saga University
    Apr. 2008 - Mar. 2015　Mitsubishi Heavy Industries, Ltd
  • Degree, etc
    Doctor of Engineering (Saga University, 2008)
  • Awards, etc
  • Academic Societies
    The Japan Society of Mechanical Engineers, The Heat Transfer Society of Japan, The Society of Sea Water Science, Japan, Deep Ocean Water Application Society, The Geothermal Research Society of Japan, Japan Desalination Association

Takeshi YASUNAGA

  • Department / Faculty Management
  • Collaboration Activities with Industry, Government, and Academina
  • External Activities
  • Educational Activities
    Takeshi YASUNAGA
  • Teaching Experience in Undergraduate Education
    Advanecd Project-Based Learning and Innovation Practice(2024-Present, Co-instructor)
    Electrical and Electronic Engineering (2024-Present)
    Mechanical Engineering Experiments I (2024-Present, Co-instructor)
    3D CAD Practice (2024-Present)
    Thermodynamics II (2024-Present)
  • Teaching Experience in Graduate Education
    Advanced Energy Conversion Engineering (2025-Present, Co-instructor)


  • Thesis Supervision
    • Bachelor Thesis: (2024) 7 students (2025) 11 students
    • Master's Thesis: (2024) 0 stundet, (2025) 0 student
    • Doctor's Thesis: (2024) 0 stundet, (2025) 0 student
  • Teaching Portfolio
  • Posture for class
    Encouraging students to focus on the fundamental nature of engineering phenomena, understand the relationship between theoretical knowledge and practical applications through real-world examples, and deepen their understanding of the underlying principles.
  • Self-evaluation of educational activities
    Conducting self-evaluations based on the results of course evaluation surveys and use the findings to inform and improve my teaching practices.
  • Training activities to improve classes
    Actively participating in faculty and staff development (FD/SD) programs both within and outside the university.
  • Active learning
    • Providing opportunities for students to learn from one another through collaborative discussion and peer learning activities.
    • In supervising undergraduate research projects, encouraging students to develop active problem-solving skills through a continuous cycle of: (1) independently identifying and addressing problems, (2) consulting and communicating with their supervisor when necessary, (3) refining and advancing their work based on feedback, and (4) critically analyzing and reflecting on the results. Through this process, students learn to take initiative and engage actively in research.
  • Outline of main course subjects and achievement targets
    • I am responsible for both hands-on and lecture-based courses. The former include 3D CAD Practice, Advanced Project-Based Learning and Innovation Practice, and Mechanical Engineering Expetiments I, while the latter include Thermodynamics II and Electrical and Electronic Engineering. Detailed information on each course is available in the syllabus.
    • Practical Training Courses: Providing students with hands-on manufacturing experience and to develop fundamental skills in project planning, design, fabrication, evaluation, and communication within group activities.
    • Thermodynamics II: Enabling students to understand the fundamentals of steam cycles and to perform basic thermal balance calculations.
    • Electrical and Electronic Engineering: Enabling students to understand the fundamentals of series circuits and to calculate basic electrical quantities in electrical circuits.
  • Level of achievement against specific goals
    More than 80% of students enrolled in my courses have successfully earned course credit.
  • Responding to requests from students
    • Improving my courses based on student feedback.
    • Accommodating individual requests whenever feasible.

Takeshi YASUNAGA

  • Books
  1. Adiputra, R., Erwandi, R., Dwiputra, A., Navik, P. N., Yasunaga, T. (Nov. 2023) Ocean Thermal Energy Conversion: Technological Readiness and Indonesia Progress,Indonesia's Energy Transition Preparedness Framework Towards 2045,Chapter 2,pp.23-86.
  2. Handbook of Water Production Technologies <Supplementary Edition> (in Japanese), Edited by the Editorial Planing Committee (Contributing author), 10 Energy Recovery Devise,pp.93-95(Apr. 2014).
  • Peer-Reviewed Journal Airticles
  1. Ohtsu, Y., Kuno, R., Yasunaga, T., Shultze, J. (Nov.2025) Spatial structure of a radio-frequency magnetron plasma at various Ar gas pressures for hydrophobic film preparation with a fluoropolymer PFA target, Vacuum,Vol.244, PartA, 114889, doi10.1016/j.vacuum.2025.1144889.
  2. Fontaine, K., Yasunaga, T., Ikegami, Y. (Mar.2025) Ocean thermal energy conversion net power maximization for the optimization of plate heat exchanger geometry, International Journal of Thermofluids,Vol.26,101115, doi10.1016/j.ijft.2025.101115.
  3. Rasgianti, Adiputra, R., Nugraha, A. D., Firdaus, N., Sitanggang, R. B., Puryantini, N., Yasunaga, T. (Sep.2024) Design Optimization of Stiffening System for Ocean Thermal Energy Conversion (OTEC) Cold Water Pipe (CWP), Results in Engineering,Vol.23, 102863, doi10.1016/j.rineng.2024.102863.
  4. Morisaki, T., Ohara, J., Yasunaga, T., Ikegami, Y. (Jun.2024) Performance Analysis of Double-stage Heat Pump And Refrigeration Cycles, Applied Thermal Engineering,Vol.253,No.15,123732,doi10.1016/j.applthermaleng.2024.123732.
  5. Borges, J. P., Waseda, T., Yasunaga, T., Ikegami, Y. (Jun.2024) Spatial and Temporal Variability of Ocean Thermal Energy Resource of the Pacific Islands, Energies,Vol.17,No.11,2766,doi10.3390/en17112766.
  6. Adiptra, R., Nugraha, A. D., Sitanggang, R. B., Pandoe, Yasunaga, T., W., Santosa, M. A., (Apr.2024) System Parameters Sensitivity Analysis of Ocean Thermal Energy Conversion, Emerging Science Journal,Vol.8,No.2,doi10.28991/ESJ-2024-08-02-04.
  7. Azmi, A. A., Yasunaga, T., Fontaine, K., Morisaki, T., Nakaoka, T., Thirugnana, S. T., Jaafar, A. B., Ikegami, Y. (Feb.2024) Basic Design Optimization of Power and Desalinated Water for Hybrid Cycle Ocean Thermal Energy Conversion System Integrated with Desalination Plant, Journal of Marine Science and Technology,Vol.29,pp.333-352,doi:10.1007/s00773-024-00988-3.
  8. Habib, M. I., Adiputra, R., Prabowo, R. P., Erwandi, E., Muhayat, N., Yasunaga, T, Ehlers, S., Braun, M. (Nov.2023) Internal flow effects in OTEC cold water pipe: Finite element modelling in frequency and time domain approaches, Ocean Engineering,Vol.288,Part-1,No.15,doi:10.1016/j.oceaneng.2023.116056.
  9. Morisaki, T., Yasunaga, T., Ikegami, Y. (May.2023) Experimental Study of Small Scale Hybrid Hot Spring Thermal Energy Conversion, Transactions of the JSME (in Japanese),Vol.89,No.921,doi: 10.1299/transjsme.22-00264.
  10. Ohtsu, Y., Hara, K., Imoto, S., Schulze, J., Yasunaga, T., Ikegami, Y. (Apr.2023) Spatial structures of rf ring-shaped magnetized sputtering plasmas with two facing cylindrical ZnO/Al2O3 targets, Japanese Journal of Applied Physics,Vol.62,doi:10.35848/1347-4065/acc7aa.
  11. Thirugnana, S. T., Bakar, A. J., Rajoo, S., Aiman, A. A., Karthikeyan, J. H., Yasunaga, T., Nakaoka, T,. Kamyab, H., Chelliapan, S., Ikegami, Y. (Feb.2023) Performance Analysis of a 10 MW Ocean Thermal Energy Conversion Plant Using Rankine Cycle in Malaysia, Sustainability,Vol.15,No.4,doi:10.3390/su15043777.
  12. Matsuda, Y., Suyama, D., Sugi, T., Goto, S., Morisaki, T., Yasunaga, T., Ikegami, Y. (Jun.2022) Construction of a state-space model with multiple flow rate inputs for an OTEC plant using Rankine cycle, SISC Journal of Control, Measurement, and System Integration, doi:10.1080/18824889.2022.2080471.
  13. Ohtsu, T., Ino, G., Sakata, J., Schulze, T., Yasunaga, T., Ikegami, Y. (Apr.2022) Spatial profile of Al-ZnO thin film on polycarbonate deposited by ring-shaped magnetized rf plasma sputtering with two facing cylindrical Al2O3 - ZnO targets, Japanese Journal of Applied Physics,doi:10.1007/s11090-021-10204-4.
  14. Urata, K, Yasunaga, T., Ikegami, Y., Omi, S., Fukami, K., Tanaka, T., Kamano, T., Ishida, M., Ohara, J., Nishida, T., Nakaoka, T. (Dec.2021) Oceanic Observation and Investigation for Ocean Thermal Energy Conversion and Deep Ocean Water Use in Coast of Kumejima Island, Deep Ocean Water Research (in Japanese),Vol.22,No.2,pp.39-47.
  15. Ohtsu, T., Ino, Y., Fujio, Y., Tbaru, T., Yasunaga, T., Ikegami, Y. (Sep.2021) Preparation of water-repellent film on a plastic plate by unbalanced radio-frequency magnetron plasma sputtering using PTFE target for a next-generation automobile window, Plasma Chemistry and Plasma Processing,doi:10.1007/s11090-021-10204-4.
  16. Yasunaga, T., Fontaine, K., Ikegami, Y. (Apr.2021) Performance evaluation concept in ocean thermal energy conversion towards standardization and intelligent design, Energies,Vol.14,No.8,doi:10.3390/en14082336.
  17. Thirugnana, T. S., Jaafar, A. B., Yasunaga, T., Nakaoka, T., Ikegami, Y., Su, S. (Apr.2021) Estimation of ocean thermal energy conversion resources in the East of Malaysia, Journal of Marine Science and Engineering,Vol.9,No.1,doi:10.3390/jmse9010022.
  18. Yasunaga, T., Ikegami, Y. (May.2020) Fundamental characteristics in power generation by heat engines on ocean thermal energy conversion (Construction of finite-time thermodynamic model and effect of heat source flow rate), Transactions of JSME (in Japanese),Vol.86,No.886,doi:10.1299/transjsme.19-00383.
    Hua, D., Yasunaga, T., Ikegami, Y. (Feb.2020) Numerical investigation of plunging phenomenon of cold water discharged from OTEC, Journal of Marine Science and Engineering,Vol.8,No.3,doi:10.3390/jmse8030155.
  19. Yasunaga, T., Ikegami, Y. (Mar.2020) Finite-Time Thermodynamic Model for Evaluating Heat Engines in Ocean Thermal Energy Conversion System, Entropy,Vol.22,No2,doi:10.3390/e22020211.
  20. Ikegami, Y.，Yasunaga, T.，Koyama, N.，Okuno, T. (Mar.2020) Parametric analysis on hybrid ocean thermal energy conversion sysytem, Transactions of JSME (in Japanese),Vol.86,No.883,doi:10.1299/transjsme.19-00370.
  21. Fontaine, K. Yasunaga, T., Ikegami, Y. (Nov.2019) OTEC Maximum Power Output Using Carnot Cycle and Application to Simplify Heat Exchanger Selection, Entropy,Vol.21,No.12,doi:10.3390/e21121143
  22. Adiputra, R., Utsunomiya, T., Koto, J., Yasunaga, T., Ikegami, Y., (Feb.2019) Preliminary design of a 100MW-net ocean thermal energy conversion (OTEC) power plant study case: Mentawai island, Indonesia, Journal of Marine Science and Technology,Vol.25,pp.48-68.
  23. Matsuda, Y., Eishima, S., Goto, T., Sugi, T., Morisaki, T., Yasunaga, T., Ikegami, Y. (Jan.2019) Water Level Control of After Condenser in a Spray Flash Desalination System Using Stochastic Process, Transactions of the Institute of Systems Control an Information Engineers,Vol.32,No.1,pp.24-31.
  24. Yasunaga, T., Noguchi, T., Morisaki, T., Yasuyuki, I. (Apr.2018) Basic Heat Exchanger Performance Evaluation Method on OTEC, Journal of Marine Science and Engineering,Vol.6,No.2,doi:10.3390/jmse6020032.
  25. Yasunaga, T.，Morisaki, T.，Ikegami, Y.，(Mar.2018) Study of avilable tehrmal energy on OTEC, Transactions of JSME (in Japanese),Vol.84,No.859,doi:10.1299/transjasme.17-00398.
  26. Ikegami, Y., Yasunaga, T., Morisaki, T. (Mar.2018) Ocean Thermal Energy Conversion Using Double-Stage Rankine Cycle, Journal of Marine Science and Engineering,Vol.6,No.2,doi:10.3390/jmse6010021.
  27. Matsuda, Y., Yoshitake, T., Sugi, T., GOto, S., Morisaki, T., Yasunaga, T., Ikegami, Y. (Feb.2018) Construction of a static model for power generation of OTEC plant using Uehara cycle based on experimental data, Journal of Marine Science and Engineering,Vol.6,No.1,doi:10.3390/jmse6010018.
  28. Matsuda, T., Urayoshi, D., Goto, S., Sugi, T., Morisaki, T., Yasunaga, T., Ikegami, Y. (Nov.2017) Seawater Flow Rate Regulation of OTEC Plant Using Uehara Cycle by Condensing Warm Seawater Temperature Variation, International Journal of Innovative Computing, Information and Control,Vol.13,No.6,pp.2123-2131.
  29. Matsuda, Y., Urayoshi, D.，Sugi, T.，Goto, S.，Morisaki, T.，Yasunaga, T.，Ikegami, Y. (Aug.2017) Construction of OTEC Potential Model Based on Cycle Analysis, Transactions of the Institure of Systems, Control and Information Engineers (in Japanese),Vol.30,No.8,pp.297-304..
    Matsuda, Y., Goto, S., Sugi, T., Morisaki, T., Yasunaga, T., Ikegami, Y. (Dec.2016) Liquid Level Control of Separator in an OTEC Plant with Uehara Cycle, Transactions of the institute system, control and Information Engineer, Vol.29,No.12,pp.535-543.
  30. Goto, S., Yamamoto, Y., Sugi, T., Yasunaga, T., Ikegami, Y., Nakamra, M. (Nov.2010) Construction of simulation model for spray flash desalination system, Electrical Engineering in Japan,Vol.170,No.4,pp.9-17.
  31. Goto, S., Motoshima, Y., Sugi, T., Yasunaga, T., Ikegami, Y., Nakamra, M. (Ari.2011) Construction of simulation model for OTEC plant using Uehara cycle, Electrical Engineering in Japan,Vol.170,No.2,pp.1-13.
  32. Goto, S., Yamamoto, Y., Sugi, T., Yasunaga, T., Ikegami, Y., Nakamra, M. (Nov.2010) Construction of simulation model for spray flash desalination system, Electrical Engineering in Japan,Vol.170,No.4,pp.9-17.
  33. Goto, S., Motoshima, Y., Sugi, T., Yasunaga, T., Ikegami, Y., Nakamra, M. (Ari.2011) Construction of simulation model for OTEC plant using Uehara cycle, Electrical Engineering in Japan,Vol.170,No.2,pp.1-13.
  34. Goto, S.，Motojima, R.，Sugi, N.，Yasunaga, T.，Ikegami, Y.，Nakamura, M. (Feb. 2009) Construction of Simulation Model for OTEC Plant Using Uehara Cycle, IEEJ Trans. PE (in Japanese),Vol.129,No.2,pp.272-282.
  35. Goto, S.，Motojima, R.，Sugi, T.，Yasunaga, T.，Ikegami, Y.，Nakamura, M. (Aug. 2008) Construction of Simulation Model for Spray Flash Desalinatio n System, EEJ Trans. PE (in Japanese),Vol.129,No.8,pp.272-282.
  36. Yasunaga, T., Ikegami, Y., Monde, M. (Feb. 2008) Performance Test of OTEC with Ammonia/water as Working Fluid Using Shell and Plate Type Heat Exchangers (Effect of Heat Source Temperature and Flow Rate), Transactions of the JSME PB (in Japanese),Vol.74,No.738,pp.445-452.
  37. Yoshizuka, K, Holba, M, Yasunaga, T., Ikegami, I. (Oct. 2007) Performance Evaluation of Benchmark Plant for Selective Lithium Recovery from Seawater, Journal of Ion Exchange,Vol.18,No.4,pp.450-453.
  38. Ikegami, Y., Yasunaga, T., Harada, H. (Feb. 2006) Optimum Mass Fraction of Working Fluid for OTEC Using the Uehara Cycle, Bulletin of the Society of Sea Water Science, Japan (in Japanese),Vol.60,No.1,pp.39-46.
  39. Ikegami, Y., Yasunaga, T., Harada, H. (Feb. 2006) Performance Experiments on Ocean Thermal Energy Conversion System Using the Uehara Cycle, Bulletin of the Society of Sea Water Science, Japan (in Japanese),Vol.60,No.1,pp.32-38.
  • Other Publications (Reviews, Commentaries, Bulletins, etc.)
  1. Yasunaga, T. (Mar.2024) Fundamental Power Generation Characteristics of Ocean Thermal Energy System and the Application s of Deep Sea Water, Bulletin of the Society of Sea Water Science, Japan (in Japanese),Vol.78,No.1,pp.38-43.
  2. 安永健, Kevin Fontaine, 大津康徳，池上康之，Sathiabama T. Thrignana, Abu Bakar Jaafar, (Feb.2024) 低エンタルピー熱発電向けヘリンボーン型プレート式熱交換器の形状最適化(熱源側の熱伝達および圧力損失の考察）, OTEC,Vol.28,pp.63-73.
  3. 安永健 (Aug.2023) 海洋エネルギー開発の現状と課題, アクアネット,Vol.26,No.8,pp.63-73.
  4. 吉村英行，大原順一，西田哲也，古賀淳司，田中辰彦，冨賀見清彦，井原剛，岡本平太，中村公彦，植田貴宏，中塚久輝，榊良祐，山本幸典，広瀬直毅，安永健，森崎敬史，浦田和 也，平山伸，池上康之 (Mar.2023) 久米島における海洋温度差発電プラント設置のための海洋調査（2016年～2022年における水温，塩分，溶存酸素量の評価）, OTEC,Vol.27,pp.35~57.
  5. Yasunaga, T., (Sep.2022) Extracting energy from seawater -A thermodynamic dilemma-, Research Features Magazine, Vol.143, pp.30-33.
  6. 安永健，森崎敬史，池上康之 (Jul.2022) ハイブリッドサイクルを用いた海洋温度差発電の開発，自動車技術，Vol.7, No.7, pp.106-112.
  7. 宮薗修路，安永健，中村泰誠，池上康之，森崎敬史 (Feb.2022) ハイブリッドサイクルを用いた海洋温度差発電のためのプレート式蒸発・凝縮器の伝熱性能評価, OTEC,Vol.26, pp.43-47.
  8. 宮﨑彬，安永健，Kevin Fontaine，池上康之 (Feb.2022) 熱力学的視点からの海洋温度差発電向け熱交換器の 性能評価手法の提案, OTEC, Vol.26, pp.19-24.
  9. 中山雅士，安永健，森崎敬史，佐々木究，大津康徳，池上康之, (Feb.2022) 透明樹脂プレート式熱交換器内部の可視化と画像処理を用いたボイド率測定方法の検討, OTEC, Vol.26, pp.19-24.
  10. 安永健, 中村泰誠, 奥野智也, 池上康之, (Dec.2020) 直交流型プレート式熱交換器を用いた海洋温度差発電の性能評価, OTEC, Vol.25, pp.69-74.
  11. 池上康之, 安永健, 奥野智也, (Sep.2019) ハイブリッドサイクルOTEC のパラメータ解析, OTEC,Vol.24, pp.41-46.
  12. 安永健, 池上康之, (Feb.2018) 海洋温度差発電の最適設計, 日本海水学会誌, Vol.73, pp.9-13.
  13. Yasunaga, T., Fontaine, K., Morisaki, T., Ikegami, Y., (Sep.2017) Performance Evaluation of Heat Exchangers for Application to Ocean Thermal Energy Conversion System, OTEC, Vol.22, pp.65-75.
  14. 安永健，(Dec.2018) 海洋温度差発電の特徴と開発動向，PETROTCH, Vol.41, pp.979-983.
  15. 安永健，森崎敬史，池上康之, (Sep.2017) 海洋温度差発電システムの性能評価手法の検討, OTEC,Vol.22, pp.37-46.
  16. 池上康之, 安永健，浦田和也，西村龍馬，鎌野忠，西田哲也, (Nov.2016) 久米島における海洋温度差発電複合利用のための海洋調査, OTEC, Vol.21, pp.36-34.
  17. 安永健, 池上康之, (Aug.2016) 海洋温度差発電Q&A，技術総合誌「オーム」, Vol.103, No.7, pp.4-9.
  18. 森﨑敬史, 安永健, 池上康之, (Jul.2015) 海洋温度差発電ポテンシャル評価, OTEC, Vol.20, pp.21-31.
  19. 安永健, 池上康之, 門出政則, (Mar.2008) アンモニア/水を作動流体として用いた30KW OTECシステムの性能評価--熱源の温度および流量の影響, OTEC, Vol.13, pp.87-94.
  20. 安永健, 池上康之, 麻生裕之, 門出政則, (Mar.2008)アンモニア/水を作動流体として用いた30KW OTECシステムの性能評価--アンモニア/水の組成の影響, OTEC, Vol.13, pp.95-102.
  • International Conferences, Domestic Conference and Symposia
  • Peer-Reviewed International Conference Proceedings
  1. Shimabukuro, K., Matsuda, Y., Wang R., Sugi, T., Morisaki, T., Yasunaga, T., Ikegami, Y. (Nov.2025) Liquid Level Control of Separator in an OTEC Plant with Uehara Cycle Using Model Predictive Control, Proceedings of the 57th ISCIE International Symposium on Stochastic Systems Theory and its Applications, Osaka, Japan, pp.81-87.
  2. Yasunaga, T., Tashiro, T., Adiputra, R., Nugroho, D., Fontaine, K., Ohtsu, Y. (Oct.2025) Theoretical Optimization of Plate-Type Condenser Geometry for Low-Temperature ORC: Case of Ocean Thermal Energy, Proceedings of 8TH International Seminar on ORC Power Systems, Lappeenranta, Finland, pp.551-560.
  3. Azmi A. A., Yasunaga, T., Fontaine, K., Thirugnana, S. T., Tasnim, R., Jaafar, A. B., Ikegami, Y (Mar.2025) An Assessment on Technical Challenges of Heat Exchanger in Hybrid OTEC, Proceedings of 18TH INTERNATIONAL CONFERENCE ON CLEAN ENERGY (AIP Conference Proceedings), Vol.3113, Issue 1, Sawarak, MALAYSIA.
  4. Matsuda, Y., Harano, S., Sugi, T., Goto, S., Morisaki, T., Yasunaga, T., Ikegami, Y. (Aug.2024) Water Level Control of a Spray Flash Desalination System Using Model Predictive Control, Proceedings of SICE Annual Conference 2024, Kochi, JAPAN, pp.643-646.
  5. Matsuda, Y., Eguchi, S., Sugi, T., Goto, S., Morisaki, T., Yasunaga, T., Ikegami, Y. (Aug.2024) Construction of a Simple Dynamic Model for STEC Plant Using Hybrid Cycle, Proceedings of SICE Annual Conference 2024, Kochi, JAPAN, pp.647-650.
  6. Matsuda, Y., Aoyagi, Y., Sugi, T., Goto, S., Morisaki, T., Yasunaga, T., Ikegami, Y. (Aug.2024) Construction of a State Space Model with Warm Seawater Flow Rate Input for OTEC Plant Using Hybrid Cycle, Proceedings of SICE Annual Conference 2024, Kochi, JAPAN, pp.651-654.
  7. Azmi A. A., Yasunaga, T., Fontaine, K., Thirugnana, S. T., Tasnim, R., Jaafar, A. B., Ikegami, Y. (Sep.2023) Effect if deep seawater design depth of an onshore 1MW hybrid ocean thermal energy conversion (OTEC) case study in Layang-Layang Island, Sabah, Malaysia, Proceedings of 7th International Seminar on ORC Power Systems, 43, Seville, Spain.
  8. Matsuda, Y., Izutsu, R., Sugi, T., Goto, S., Morisaki, T., Yasunaga, T., Ikegami, Y. (Jul.2023) Net Power Generation Control of OTEC Plant Using Rankine Cycle with Seawater Pumps by Warm Seawater Flow Rate Regulation, Preprints of the 22nd World Congress, The International Federation of Automatic Control (IFAC PapaersOnline), Yokohama, JAPAN, Vol.56,No.2. pp.2257-2280.
  9. Matsuda, Y., Ehara, A., Sugi, T., Goto, S., Morisaki, T., Yasunaga, T., Ikegami, Y. (Sep.2022) Construction of a State Space Model for a Spray Flash Desalination System with Valve Dynamics, Proceedings of 61st Annual Conference Society of Instrument and Control Engineers 2022, pp.448-453, Kumamoto, Japan
  10. Matsuda, Y., Suyama, D., Sugi, T., Goto, S., Morisaki, T., Yasunaga, T., Ikegami, Y. (Sep.2022) Construction of a State Space Model with Working Fluid Flow Rate Inputs for an OTEC Plant Using Double-stage Rankine Cycle, Proceedings of 61st Annual Conference Society of Instrument and Control Engineers 2022, pp.427-447, Kumamoto, Japan.
  11. Matsuda, Y., Izutsu, D., Sugi, T., Goto, S., Morisaki, T., Yasunaga, T., Ikegami,Y. (Sep.2022) Power Generation Control of OTEC Plant Using Hybrid Cycle by Cold Seawater Flow Rate Regulation, Proceedings of 61st Annual Conference Society of Instrument and Control Engineers 2022, pp.71-74, Kumamoto, Japan.
  12. Ushijima, K., Matsuda, Y., Sugi, T., Goto S., Morisaki, T., Yasunaga, T., Ikegami, Y. (Mar.2022) A Pseudo-measurement Approach to State Estimation for Liquid Level Control of Separator in an OTEC Plant Using Uehara Cycle, Proceedings of the 53rd ISCIE International Symposium on Stochastic Systems Theory and Its Applications, pp.129-134, Shiga, Japan.
  13. Martine, B., Okamura, S., Yasunaga, T., Ikegami, Y., Ohta, N. (Feb.2022) OTEC and Advanced Deep Ocean Water Use for Kumejima: An Introduction, Proceedings of OCEANS 2022 –Chennai (Online).
  14. Yasunaga, T., Nakamura, T., Okuno, T., Ikegami, Y. (Oct.2021) Exergetic performance evaluation of ocean thermal energy conversion system with crossflow plate heat exchangers, Proceedings of 6th International Symposium on ORC Power Systems, 87, Munich, Germany (Online).
  15. Yasunaga, T., Miyazaki, A., Fontaine, K., Ikegami, Y. (Oct.2021) Comprehensive heat exchanger performance evaluation method on ocean thermal energy conversion for maximum net power, Proceedings of 6th International Symposium on ORC Power Systems, 48, Munich, Germany (Online).
  16. Matsuda, Y., Sugi, T., Goto S, Takafumi Morisaki, Yasunaga, T., Ikegami, Y. (Sep.2021) Construction of a dynamic model for an OTEC plant using hybrid cycle based on a simple dynamic model, Proceedings of SICE Annual Conference 2021,pp.180-183 Tokyo, Japan (Online).
  17. Matsuda, Y., Suyama, D., Sugi, T., Goto S, Takafumi Morisaki, Yasunaga, T., Ikegami, Y. (Sep.2021) Construction of a state space model with working fluid flow rate input for an OTEC plant using Rankine cycle, Proceedings of SICE Annual Conference 2021, pp.176-179, Tokyo, Japan (Online).
  18. Yasunaga, T., Okuno, T., Ikegami, Y. (Jul.2020) Parametric analysis of novel self-water supply ORC power system for hot spring thermal energy conversion, Proceedings of IIR Rankine Conference 2020, Glasgow, UK (Online).
  19. Yasunaga, T., Y. Ikegami, (JUl.2020) Theoretical model construction for renewable low-grade thermal energy conversion: an insight from finite-time thermodynamics, Proceedings of IIR Rankine Conference 2020, Glasgow, UK (Online).
  20. Matsuda, Y., Sakai, R., Sugi, T., Goto S, Yasunaga, T., Ikegami, Y. (Sep.2020) Construction of a state space model for a spray flash desalination system, Proceedings of 4th IEEE Conference on Control Technology and Applications, pp.922-927, Montreal, Canada (Online).
  21. Matsuda, Y., Sakai, R., Sugi, T., Goto S, Yasunaga, T., Ikegami, Y. (Nov.2019) Control system for water level control of flash chamber in a spray flash desalination system via Stochastic processes, Proceedings of the 51st ISCIE International Symposium on Stochastic Systems Theory and Its Applications, pp.7-17, Fukushima, Japan.
  22. Matsuda, Y., Sakai, R., Sugi, T., Goto S, Yasunaga, T., Ikegami, Y. (Oct.2019) Water level control of flash chamber in a spray flash desalination system with valve dynamics and flow rate limitation, Proceedings of 19th International Conference on Control, Automation and System, pp.879-884, Jeju, Korea.
  23. Yasunaga, T., Y. Ikegami (Sep.2019) Irreversibility in the organic Rankine cycle for low-grade thermal energy conversion system, Proceedings of 5th International Seminar on ORC Power Systems, Athena, Greece.
  24. Matsuda, Y., Oouchida, D., Sugi, T., Goto S, Yasunaga, T., Ikegami, Y. (Sep.2019) Power generation control of OTEC plant Using Double-stage rankine cycle with target power output variation by simultaneous regulation of multiple flow rates, Proceedings of SICE Annual Conference 2018, pp.10-13, Hiroshima, Japan.
  25. Aosaki, Y., Matsuda, Y., Sugi, T., Goto S, Yasunaga, T., Ikegami, Y. (Jun.2019) Model construction of OTEC plant Using double-stage Rankine cycle with time delay by considering separator and working fluid tank, Proceedings of 2019 12th Asian Control Conference (ASCC2019), pp.358-363, Fukuoka, Japan.
  26. Matsuda, Y., Sakai, R., Goto, S., Sugi, T., Morisaki, T., Yasunaga, T., Ikegami, Y. (Oct.2018) Anti-windup Compensation for Water Level Control of a Spray Flash Desalination System with Flow Rate Limitations, '''Proceedings of 2nd IEEE Conference on Control Technology and Applications, pp.1363-1368.
  27. Matsuda, Y., Oouchida, R., Sugi, T., Goto, S., Morisaki, T., Yasunaga, T., Ikegami, Y. (Sep.2018) Simultaneous Regulation of Multiple Flow Rates for Power Generation Control of OTEC Plant Using Double-stage Rankine Cycle, Proceedings of SICE Annual Conference 2018, pp. 983-988, Nara, Japan.
  28. Yasunaga, T., Koyama, N., Noguchi, T., Morisaki, T., Ikegami, Y. (Jun.2018) Thermodynamical optimum heat source mean velocity in heat exchangers on OTEC, Grand Renewable Energy 2018, O-Oe-3-2, Yokohama, Japan.
  29. Matsuda, Y., Sakai, R., Sugi, T., Goto, S., Morisaki, T., Yasunaga, T., Ikegami, Y. (Oct.2018) Anti-windup Compensation for Water Level Control of a Spray Flash Desalination System with Flow Rate Limitations, Proceedings of 2nd IEEE Conference on Control Technology and Applications, Copenhagen, Denmark, pp. 1363-1368.
  30. Matsuda, Y., Eishima, Y., Goto, S., Sugi, T., Morisaki, T., Yasunaga, T., Ikegami, Y. (Jun.2018) Construction of Water Level Model for After Condenser in Spray Flash Desalination System via Stochastic Process, Proceeding of the 49th ISCIE International Symposium on Stochastic Systems Theory and Its Applications, pp.100-105, Hiroshima, Japan.
  31. Matsuda, Y., Goto, S., Sugi, T., Morisaki, T., Yasunaga, T., Ikegami, Y. (Sep.2017) Evaluation of a Liquid Level Model of Separator in an OTEC Experimental Plant Using Uehara Cycle via Different Experimental Data, Proceedings of SICE Annual Conference 2017, pp.1490-1495, Kanazawa, Japan.
  32. Yasunaga, T., Ikegami, Y. (Sep.2017) Application of Finite-time Thermodynamics for Evaluation Method of Heat Engines, Energy Procedia, Vol.129, pp.995-101.
  33. Matsuda, Y., Goto, S., Sugi, T. Morisaki, T., Yasunaga, T., Ikegami, Y. (Jul.2017) Control of OTEC Plant Using Double-stage Rankine Cycle Considering Warm Seawater Temperature Variation, IFAC-PapersOnLine, Vol.50, No.1, pp.135-140.
  34. Goto, S., Matsuda, Y., Sugi, T., Morisaki, T., Yasunaga, T., Ikegami, Y., Egashira, N. (Jul.2017) Web Application for OTEC Simulator Using Double-stage Rankine Cycle, IFAC PapersOnLine, Vol.50, No.1, pp.121-128.
  35. Matsuda, Y., Goto, S., Sugi, T., Morisaki, T., Yasunaga, T., Ikegami, Y. (Sep.2017) An Improvement on LQG Controller for Liquid Level Control of Separator in an OTEC Experimental Plant Using Uehara Cycle, Proceedings of SICE Annual Conference 2017, pp.1496-1501, Kanazawa, Japan.
  36. Matsuda, Y., Goto, S., Sugi, T., Morisaki, T., Yasunaga, T., Ikegami, Y. (Jan.2017) Model Construction of Warm Water Temperature of Heat Source in an OTEC Experimental Plant via Stochastic Process, Proceedings of the 48th ISCIE International Symposium on Stochastic Systems Theory and Its Applications, Fukuoka Institute of Technology, pp.70-75, Fukuoka, Japan.
  37. Matsuda, Y., Goto, S., Sugi, T. Morisaki, T., Yasunaga, T., Ikegami, Y., Egashira, N. (Jul.2017) Control of OTEC Plant Using Double-stage Rankine Cycle Considering Warm Seawater Temperature Variation, IFAC PapersOnLine, Vol.50,No.1,pp.135-140.
  38. Matsuda, Y., Goto, S., Sugi, T., Morisaki, T., Yasunaga, T., Ikegami, Y. (Jul.2017) Web Application for OTEC Simulator Using Double-stage Rankine Cycle, IFAC PapersOnLine, Vol.50,No.1,pp.121-128.
  39. Matsuda, Y., Goto, S., Sugi, T., Morisaki, T., Yasunaga, T., Ikegami, Y. (Jul.2017) An Improvement on LQG Controller for Liquid Level Control of Separator in an OTEC Experimental Plant Using Uehara Cycle, Proceedings of 56th Annual Conference Society of Instrument and Control Engineers 2017, pp.1496-1501.
  40. Martin, B., Okamura, S., Nakamura, Y., Yasunaga, T., Ikegami,Y. (Oct.2016) Status of the "Kumejima Model" for advanced deep seawater utilization, Proceedings of The Techno-Ocean 2016, pp.21-216, Kobe, Japan.
  41. Nakamura, M., Kawabata, Y., Yasunaga, T., Ikegami,Y. (Aug.2016) The Visualization of Phase Change Phenomena in Herringbone Type Plate Heat Exchanger Using 3D-printer, Proceedings of The 27th ISTP (International Symposium on Transport Phenomena), ITSP-206, Hawaii, USA.
  42. Ikegami, Y., Inadomi, J., Yasunaga, T., Aso, H. (Jul.2008) Experimental study of OTEC using ammonia/water mixture as working fluid, Proceedings of 18th International Offshore and Polar Engineering Conference, Vancouver, Canada.
  43. Aso, H., Yasunaga, T., Ikegami, Y. (Jun.2007) Comparison between Kalina cycle and conventional OTEC system using ammonia-water mixtures as working fluid, Proceedings of 17th International Offshore and Polar Engineering Conference, Lisbon, Portugal.
  44. Ikegami, Y., Yasunaga, T., Harada, H. (Jan.2007) Experimental performance evaluation of ocean thermal energy conversion system using Uehara cycle, Proceedings of Grand Renewable Energy 2006，Yokohama, Japan.
  45. Yasunaga, T., Harada, H., Ikegami, Y. (Jan.2007) Characteristics and estimation of ocean thermal energy conversion system using Uehara cycle, Proceedings of Grand Renewable Energy 2006，Yokohama, Japan.
  46. Ikegami, Y., Yasunaga, T., Uehara, H. (May.2005) Effect of regenerator heat transfer performance on the cycle thermal efficiency of OTEC using smmonia-water as working fluid, Proceedings of 15th International Offshore and Polar Engineering Conference，Soul, Korea.
  47. Ikegami, Y., Yasunaga, T., Uehara, H. (Mar.2005) Performance improvement of ocean thermal energy conversion system usisn ammonia/water mixtures as working fluid, Proceedings of The Sixth KSME-JSME Thermal and Fluids Engineering Conference, Jeju, Korea.
  • Competitive Research Fundings, Patents, copyrights, etc.
  • Competitive Research Funding
  1. 科研費 基盤研究(C)　（代表, 2025-2028）
  2. 岩谷科学技術研究助成金　(代表，2025)
  3. 公益財団法人 JKA 機械振興補助事業 研究概要 (代表，2022-2023)
  4. 科研費 基盤研究(C)　（分担, 2021-2023）
  5. 科研費 基盤研究(C)　（代表, 2020-2022）
  6. 公益財団法人 JKA 機械振興補助事業 研究概要 (分担，2020-2021)
  7. 科研費 基盤研究(C)　（分担, 2018-2020）
  • Patents
  1. Kakizaki N., Koseki K., Ikegami Y., Yasunaga T. (2019) The power generation system and power generation method, 特願2019-176005, WO2020/235497 (PCT/JP2020/019492), 特許6928937, TW202108872, IDP000084979.MY195650A.
  2. Yasunaga T., Ikegami Y., Watanabe T., Jitsuhara S. (2018) Desalination and temperature difference power generation system, 特願2018-161843, WO2020/45659 (PCT/JP2019/034241), 特許7115680, IDP000091157.
  3. Ikegami Y., Yasunaga T., Watanabe T., Jistuhara S. (2018) Heat Exchanger, 特願2018-161844, WO2020/45662, (PCT/JP2019/034253), 特許7144005, IDP000086269.
  4. 田畑 雅之, 伊藤 嘉晃, 松井 克憲, 徳永 貴一, 池 卓, 竹内 和久, 岩橋 英夫, 安永 健, 岸 正弘 (2016) 水処理システム及び水処理方法, 特願2016-239459.
  5. Tabata M., Ito Y., Matsui K., Tokunaga K., Ike T., Takeuchi K., Iwahashi H., Yausnaga T., Kishi M. (2013) Water treatment system and water treatment method, 特願2013-140014, WO2015002194 (PCT/JP2014/067540)US20160122219, EP14820665.9, SG11201509724, AU20142285172.
  6. Hashimoto, Y., Iwahashi, H., Matsui, K., Tokunaga, K., Yausnaga, T., Tabata, M., Ito, Y., Takeuchi, K., Kishi, M., Gouda, Y., (2015) Water Treatment System, 特許6118668 (特願2013-140013), WO2015002186 (JPT2014/067515), EP14819445.9, AU2014285164, SG11201509709, US10513452.
  7. 徳永貴一，安永健，(2013) 逆浸透膜装置, 特許6033118 (特願2013-35609).
  8. Tokunaga, K., Yasunaga, T., Ito, Y., Hashimoto, Y., (2014) Reverse osmosis membrane apparatus and method of operating same, 特願2013-035023, WO2014129340 (PCT/JP2014/053008), 特許6057770, EP14754840.8, US10202291., SA515360936A.
  9. Tokunaga, K., Yasunaga, T., (2013) Method of operating reverse osmosis membrane device, 特願2013-030682, WO2014129341 (PCT/JP2014/053009), 特許6057770, US10294127, EP14754337.5.
  10. 吉田正，安永健，林健太郎，三浦正美，(2013) モジュール浮体発電装置，特願2013-021631.
  11. 安永健，谷口昇，後藤正人，藤田京孝，内田聡，林健太郎，(2012) 波力発電装置およびその制御方法，特願2012-044678.
  12. 安永健，谷口昇，後藤正人，林健太郎，池末俊一，太田真，岩崎聡，(2012) 波力発電装置およびこれを備えた浮体構造物ならびに波力発電装置の制御方法，特願2012-027420.
  13. 吉田正，安永健，谷口昇，林健太郎，高崎周二，三浦正美，(2012) 波力発電装置及びその制御方法，特願2012-014352.
  14. 林健太郎，安永健，岩崎聡 (2012) 波力発電装置，特願2012-014351.
  15. 安永健，林健太郎，池末俊一，太田真，三浦正美，鷹本靖欣，小林由則，橋本秀昭，金子祥三，橋本彰，(2011) 波力発電装置，特願2011-080750, WO2012124747 (PCT/JP2012/056613), 特許5738043, AU201600649A, US14/002,189, CN201280011031.6A, EP12757378.0A.
  16. 安永健，林健太郎，池末俊一，太田真，金子祥三，橋本彰，(2011) 波力発電装置，特願2011-080749,特許5766484.
  17. 安永健，林健太郎，池末俊一，太田真，三浦正美，鷹本靖欣，小林由則，橋本秀昭，金子祥三，橋本彰，(2011) 波力発電装置の固有振動調整機構，特願2011-080748, WO2012124747A1 (PCT/JP2012/056613), 特許5627528, EP12757378.0A, AU2012229831A, CN201280011031.6A, US14/002,189.
  18. Hayashi, K., Yasunaga, T., Ikesue, S., Ohta, M., Miura, M., Takamoto, Y., Kobayashi, Y., Hashimoto, H., Kaneko, S., (2011) Natural Vibration adjustment mechanism of wave power generator, 特願2011-080747, WO2012/124747 (PCT/JP2012/056613), 特許5627527, EP12757378, CN201280011031, US14/022,189, AU2016200649.
  19. Ikesue, S., Yasunaga, T., Ohta, M., (2011) Wave-power electricity generating device, 特願2009-272765, WO2011065170 (PCT/JP2010/068944), JP5308317, CN2010800536983, US8555632, AU2010323869, GB1209175.7.
  • Activities in academic societies
  1. 2023 The 7th International Seminar on Organic Rankine Cycle Power System, Review Chair
  2. 2022 The 26th JSME Power and Energy System Symposium Organization Committee
  3. 2021 JSME Thermal Engineering Conference 2021 Organization Committee
  4. 2018 Executive Director, The 6th International OTEC Symposium Organization Committee

Takeshi YASUNAGA

  • Contribution in the local community
  • Committee members, officers, etc. in public institutions


  • Organization management such as academic societies
  1. Board Member, Deep Ocean Water Application Society (April, 2018-Present)　
  2. Secretary General, Deep Ocean Water Application Society (April, 2016-March, 2020)


  • Disaster relief activities in Japan and overseas


  • Other activities