Profile Information
- Affiliation
- Professor, Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency
- Degree
- Doctor of Engineering(Mar, 1996, Nagoya University)
- Contact information
- ogawa.hiroyuki
jaxa.jp
- J-GLOBAL ID
- 200901051344540154
- researchmap Member ID
- 1000253790
- External link
Research on advanced thermal control systems for future scientific satellites
Based on the experience of scientific satellite projects, we analyze the current issues and future plans, and conduct research and development of advanced thermal control systems for future scientific satellites. The results of our research have been fed back to the thermal control system on board the X-ray astronomy satellite Hitomi, and are being considered for application to the next scientific satellite project.
Thermal control for scientific satellite projects
In challenging projects that actively employ thermo-fluid devices, such as the Japan-Europe Mercury mission BepiColombo, which will be exposed to extreme environments that have never been experienced before, and the large X-ray telescope satellite Hitomi, new satellite development methods that have never been experienced before are required. In such challenging projects that actively employ thermo-fluid devices, conventional satellite development methods and their extensions cannot be applied. We are contributing to the success of the project from the viewpoint of heat by leading the new research and development with our academic knowledge of thermo-fluid mechanics, such as development of new materials that can withstand extreme environments, construction of thermal design and analysis methods, development of test facilities, and development of verification methods.
Application of thermo-fluid mechanics
We are contributing to various space science project activities based on our academic knowledge of thermo-fluid and its related fields. In the research of reusable rockets, we are contributing to the solution of problems related to thermo-fluid such as engine flow, cryogenic tanks, and external flow. In the area of satellite propulsion, we have contributed to the improvement of thruster analysis technology by studying the chemical reaction flow inside hydrazine thrusters, and in the area of rocket propulsion, we have developed a method for analyzing the internal flow of solid rockets and contributed to the investigation of the causes of malfunctions in M-V rockets and SRB-A rockets. In the rocket propulsion system, he developed an internal flow analysis method for solid rockets and contributed to investigating the cause of the failure of the M-V rocket and SRB-A. He has also contributed to rocket research by working on rocket flight safety and radio frequency interference problems with rocket exhaust plumes. I have also conducted theoretical research on shock wave interference in high-speed electromagnetic fluids and propulsion systems using electromagnetic fluids.
Research Interests
8Research Areas
4Research History
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Jan, 2002 - Sep, 2003
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Apr, 1996 - Mar, 1998
Education
1Committee Memberships
1-
Mar, 2013 - Feb, 2015
Awards
1-
2015
Papers
95-
Applied Thermal Engineering, 264, Apr 1, 2025A loop heat pipe is a two-phase fluid loop driven by capillary force. Fabrication of a loop heat pipe evaporator by additive manufacturing has been investigated as a low-cost, quick-delivery method for producing a high-performance loop heat pipe. This study investigated the evaporation and heat transfer performance of a wick-integrated evaporator fabricated by additive manufacturing. It is essential to understand the thermal characteristics of the evaporator for a loop heat pipe with an additive-manufactured evaporator for all applications. A tested loop heat pipe with an additive-manufactured evaporator achieved a maximum heat transport capability of 120 W (heat flux: 7.96 W/cm2) and a minimum thermal resistance of 0.321 °C/W in the horizontal orientation at a 20 °C sink temperature. The evaporative heat transfer coefficient and heat leak ratio to the reservoir were calculated for each orientation test result. The maximum evaporative heat transfer coefficient was 50 kW/m2/K and the heat leak ratio was less than 10 % between 10 W and 70 W in the horizontal orientation. These results reveal that the increase in heat leakage to the reservoir due to the decrease in the evaporative heat transfer coefficient leads to the increase in the loop heat pipe operating temperature and thermal resistance. The novelty of this study is that it clarifies the relationship between a loop heat pipe's thermal resistance and evaporator thermal performance by correlating the evaporative heat transfer coefficient and the heat leakage of the wick-integrated evaporator, which uses additive manufacturing, based on the heat transport test results in each orientation.
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International Journal of Thermal Sciences, 207, Jan, 2025A cryogenic capillary pumped loop (CCPL) is a highly efficient two-phase capillary-force-driven heat transport device that operates at cryogenic temperatures. CCPL satisfies the demands for space applications in cryogenic regions as it can transport heat over long distances without mechanical moving parts. In this study, the transient internal flow during the supercritical startup of CCPL was predicted, and various temperature relationships were used to determine whether CCPL starts up or not. The utilized CCPL comprised a wick (pore radius = 1.0 μm), exhibited a heat transport distance of 2 m, and was filled with nitrogen as the working fluid. The supercritical startup experiments were performed at a temperature range of 77–300 K; the startup procedure was initiated when the maximum temperature of CCPL decreased to ∼150 K. Three different liquid supply cycles were tested during the supercritical startup, and the startup time was reduced (a maximum and minimum of 4.1 and 1.9 h, respectively). CCPL started when the evaporator temperature was below the cold reservoir temperature. Thus, the temperature relationship between the cold reservoir and evaporator at the time of applying the heat load to the evaporator could be used to determine the possibility of starting CCPL. The startup was considered successful when the cold reservoir temperature was higher than the evaporator temperature, as the cold reservoir, which exhibited a two-phase state, supplied sufficient liquid to the evaporator, filling the inside of the evaporator with liquid.
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International Journal of Heat and Mass Transfer, 231, Oct, 2024This paper investigated the effect of filling pressure on the operating characteristics of a gravity-assisted cryogenic loop heat pipe(CLHP) for use in gravity environments such as terrestrial and lunar environments. The CLHP wick is made of sintered stainless-steel fibers with a pore radius of 1.56 μm and designed with a heat transport distance of 2.05 m. The experiments were conducted under gravity-assisted conditions (the condenser was placed 0.1 m higher than the evaporator). Notably, the filling pressure originated from the assumed vapor-liquid distribution in the CLHP under steady-state conditions. The filling pressure was varied from 2.9 MPa to 3.4 MPa in 0.1 MPa increments for six different conditions. Specifically, (1) 2.9 MPa and (2) 3.0 MPa are conditions where the heat leakage due to the vapor phase in the evaporator core is large, while (3) 3.1 MPa and (4) 3.2 MPa are conditions where there is no vapor phase in the evaporator core and the surplus vapor phase escapes to the CC. In general, this condition is considered to be the optimum amount of working fluid for room-temperature LHPs when designing. (5) 3.3 MPa and (6) 3.4 MPa are overfilling conditions that cause the CC to be filled with liquid. The results revealed that the higher the filling pressure, the more obvious the variation in operating temperature caused by the transition of drive modes. The maximum heat transfer capability reached 25 W in cases (1)-(4). In cases (5) and (6), the heat transfer capabilities increased to 30 W, although the operating temperature was higher. Furthermore, the hysteresis effect under different filling pressure conditions was newly confirmed. The power cycling experiments demonstrated that hysteresis in the operating temperature occurred at high heat loads and showed a similar trend to the room-temperature LHP.
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Journal of Evolving Space Activities, 2 156, Jul 25, 2024 Peer-reviewed
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Applied Thermal Engineering, 255 123878-123878, Jul, 2024One of the main advantages of a cryogenic loop heat pipe (CLHP) is its heat transfer capability over long distances and operability under anti-gravity conditions. However, there are only a few studies on the thermal characteristics of long-distance CLHPs. It is essential to investigate the effect of a hydraulic head on CLHP performance to enhance the utilization of CLHPs in various applications. This study investigated the thermofluidic behaviors of a 2-m nitrogen CLHP with a capillary starter pump (CSP) under horizontal and anti-gravity conditions where the evaporator was 350 mm higher than the condenser. The novelty of the study is to reveal the heat transfer characteristics and operating mechanisms under anti-gravity conditions based on comparisons with experimental results under horizontal conditions. In the CLHP, a fine stainless-steel porous wick with a pore radius of 1.0 μm and permeability of 1.3 × 10−13 m2 was used for an evaporator and the CSP. The lengths of the vapor line, condenser, and liquid line were 2000, 1500, and 2000 mm, respectively. When a heat load of 4 W was applied to the CSP and evaporator, the CLHP successfully started with an initial cooling condition called a supercritical startup under anti-gravity conditions. The startup temperature behaviors were compared under horizontal and anti-gravity conditions. The thermal resistance of the CLHP with a stepped-up evaporator heat load and various CSP heat loads was evaluated for two CLHP orientations. The CLHP stably operated under evaporator heat loads of 4–24 W (horizontal) and 4–20 W (anti-gravity) for three CSP heat loads of 0, 2, and 4 W. The effect of the CLHP orientation on the thermal resistance with various CSP heat loads is discussed. This study enhances the applicability of the long-distance CLHP to various applications with a high degree of postural freedom by revealing the operating mechanism and thermal characteristics of the long-distance CLHP under anti-gravity and horizontal conditions.
Misc.
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宇宙科学技術連合講演会講演集(CD-ROM), 67th, 2023
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宇宙科学技術連合講演会講演集(CD-ROM), 67th, 2023
Books and Other Publications
1Presentations
33-
46th International Conference on Environmental Systems, Jul, 2016
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第16回宇宙科学シンポジウム 講演集 = Proceedings of the 16th Space Science Symposium, Jan, 2016, 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)第16回宇宙科学シンポジウム (2016年1月6日-7日. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)相模原キャンパス), 相模原市, 神奈川県資料番号: SA6000046247レポート番号: S4-010
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45th International Conference on Environmental Systems, Jul, 2015
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44th International Conference on Environmental Systems, 2014
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42nd International Conference on Environmental Systems, Jul, 2012
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41st International Conference on Environmental Systems, Jul, 2011
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40th International Conference on Environmental Systems, Jul, 2010
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34th AIAA Fluid dynamics conference and exhibit, 2004
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33rd International Conference on Environmental Systems, SAE-2003-01-2689, Jul, 2003
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32rd International Conference on Environmental Systems, 2002-ICES-236, Jul, 2002
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宇宙航行の力学シンポジウム 平成13年度, 2002
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日本航空宇宙学会年会講演会講演集, 2002
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宇宙科学シンポジウム, Nov 19, 2001, 宇宙航空研究開発機構宇宙科学研究本部
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日本機械学会関東支部総会講演会講演論文集, 2000, The Japan Society of Mechanical EngineersShock waves in a vapor of n-perfluoropentane (C_5F_<12>) and of n-perflurooctane (C_8F_<18>) are studied. Since both have high molar heat capacities and low specific heat ratios, their vapors condense behind a weak shock. The Rankine-Hugoniot analyses show that condensation occurs behind a shock in a C_5F_<12> vapor, while it does not in a C_8F_<18> vapor. Analytical results agree very well with experiments for C_5F_<12>.
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惑星探査への気体力学の先端的応用 平成8-10年度 No.08305036, 1999
Professional Memberships
5-
Sep, 2020
Research Projects
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科学研究費助成事業, 日本学術振興会, Apr, 2023 - Mar, 2027
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科学研究費助成事業, 日本学術振興会, Apr, 2024 - Mar, 2026
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科学研究費助成事業, 日本学術振興会, Apr, 2023 - Mar, 2026
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Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), Japan Society for the Promotion of Science, Apr, 2018 - Mar, 2021
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Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research, Japan Society for the Promotion of Science, Apr, 2016 - Mar, 2018
Industrial Property Rights
6Academic Activities
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Panel moderator, Session chair, etc., Peer reviewJul, 2003 - Present
● 指導学生等の数
6-
Fiscal Year2018年度(FY2018)Doctoral program1
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Fiscal Year2019年度(FY2019)Doctoral program2Master’s program1JSPS Research Fellowship (Young Scientists)1
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Fiscal Year2020年度(FY2020)Doctoral program1Master’s program1JSPS Research Fellowship (Young Scientists)1
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Fiscal Year2018年度(FY2018)Doctoral program1
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Fiscal Year2019年度(FY2019)Doctoral program2Master’s program1JSPS Research Fellowship (Young Scientists)1
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Fiscal Year2020年度(FY2020)Doctoral program1Master’s program1JSPS Research Fellowship (Young Scientists)1
● 専任大学名
2-
Affiliation (university)東京大学(University of Tokyo)
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Affiliation (university)東京大学(University of Tokyo)
● 所属する所内委員会
6-
ISAS Committee研究所会議
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ISAS Committeeプログラム会議
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ISAS Committee信頼性品質会議
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ISAS Committee環境・安全管理統括委員会
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ISAS CommitteeISASニュース編集小委員会
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ISAS Committee宇宙科学プログラム技術委員会