研究者業績
基本情報
- 所属
- 国立研究開発法人宇宙航空研究開発機構 宇宙科学研究所 教授
- 学位
- 博士(工学)(1996年3月 名古屋大学)
- 連絡先
- ogawa.hiroyuki
jaxa.jp - J-GLOBAL ID
- 200901051344540154
- researchmap会員ID
- 1000253790
- 外部リンク
将来の科学衛星に向けた先進的熱制御システムの研究
科学衛星プロジェクトの経験を基に，現状の課題と将来計画を分析し，将来の科学衛星に必要な先進的熱制御システムの研究開発をおこなっています．研究成果はX線天文衛星ひとみに搭載された熱制御システムにフィードバックされている他，次期科学衛星計画への適用が検討されている等，科学衛星の可能性を広げ，世界一流の成果を創出する活動に貢献しています．
科学衛星プロジェクトの熱制御
日欧水星探査計画BepiColombo等のこれまで経験のない極限環境に晒される探査機や，X線大型望遠鏡衛星ひとみ等の熱流体デバイスを積極的に採用した挑戦的プロジェクトにおいては，従来の衛星開発手法やその延長線上では対応できず，これまで経験のない新しい衛星開発手法が求められます．極限環境に耐える新規材料開発や熱設計・解析手法の構築，試験設備整備や検証手法の開発など，新しい研究開発を熱流体力学の学術的知見をもって先導し，熱の観点でプロジェクトの成功に貢献しています．
熱流体力学の応用
熱流体とその周辺の学術的知見を基に，さまざまな宇宙科学プロジェクト活動に貢献しています．再使用ロケットの研究では，エンジン流れや極低温タンク，外部流等熱流体にかかわる課題解決に貢献しています．衛星推進系ではヒドラジンスラスタ内部化学反応流の研究によりスラスタ解析技術の向上に貢献し，ロケット推進系では固体ロケット内部流解析手法を開発し，M-VロケットやSRB-Aの不具合原因究明に貢献しました．その他，ロケットの飛行安全やロケット排気プルームの電波干渉問題等に関わり，ロケット研究に貢献しています．また高速電磁流体中の衝撃波干渉の理論研究や電磁流体を利用した推進システムの研究をおこないました．
経歴
6-
2017年1月 - 現在
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2003年10月 - 2016年12月
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2002年1月 - 2003年9月
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1998年4月 - 2001年12月
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1996年4月 - 1998年3月
学歴
1-
- 1996年3月
委員歴
1-
2013年3月 - 2015年2月
受賞
1-
2015年
論文
95-
Applied Thermal Engineering 264 2025年4月1日A 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 2025年1月A 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 2024年10月This 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 2024年7月25日 査読有り
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Applied Thermal Engineering 255 123878-123878 2024年7月One 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
382-
2013 IEEE 39TH PHOTOVOLTAIC SPECIALISTS CONFERENCE (PVSC) 647-651 2013年Emcore has been performing High Intensity High Temperature (HIHT) tests on covered, interconnected cell (CIC) assemblies. End-of-life performance of spacecraft solar panels depends to a great extent on changes in the optical properties of the CICs' coverglass adhesive during the mission. An important change in silicone coverglass adhesives is observed as degradation of short wavelength transmission, often called "darkening" or "yellowing". This is understood to be driven by exposure to high intensity UV and by exposure to elevated temperature. Solar panels on the Solar Probe Plus (SPP) spacecraft will be exposed to both high UV irradiance and elevated temperature over the course of a long mission. This paper reports on the thermal-mechanical design work performed and planned by Emcore in order to test CICs designed for SPP under these extreme conditions. Three types of thermal test designs are presented: conduction/convection with a single fixed temperature, thermal radiation with multiple fixed temperatures, and thermal radiation with a variable single temperature. We present some detail from predictive thermal models used in the test designs along with temperature data measured during the test runs.
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Proceedings of SPIE - The International Society for Optical Engineering 8443 2012年10月16日The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly successful X-ray missions initiated by the Institute of Space and Astronautical Science (ISAS). ASTRO-H will investigate the physics of the high-energy universe via a suite of four instruments, covering a very wide energy range, from 0.3 keV to 600 keV. These instruments include a high-resolution, high-throughput spectrometer sensitive over 0.3-2 keV with high spectral resolution of Delta E < 7 eV, enabled by a micro-calorimeter array located in the focal plane of thin-foil X-ray optics; hard X-ray imaging spectrometers covering 5-80 keV, located in the focal plane of multilayer-coated, focusing hard X-ray mirrors; a wide-field imaging spectrometer sensitive over 0.4-12 keV, with an X-ray CCD camera in the focal plane of a soft X-ray telescope; and a non-focusing Compton-camera type soft gamma-ray detector, sensitive in the 40-600 keV band. The simultaneous broad bandpass, coupled with high spectral resolution, will enable the pursuit of a wide variety of important science themes.
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42nd International Conference on Environmental Systems 2012年7月 筆頭著者
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42nd International Conference on Environmental Systems 2012年7月 筆頭著者
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Proceedings of the International Astronautical Congress, IAC 11 8842-8847 2012年A new reusable sounding rocket is proposed (1) to reduce operation costs from that of existing expendable sounding rockets and (2) to provide frequent launch opportunities. This paper describes the current status of the conceptual design of the reusable sounding rocket, including system concept, mission profile and system configuration. Some of the R&D status is also presented. Copyright © (2012) by the International Astronautical Federation.
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42nd International Conference on Environmental Systems 2012, ICES 2012 2012年The inflation and peel-off characteristics of a multilayer insulation (MLI) blanket under a depressurization environment have been evaluated for establishing a JAXA design standard. The venting conductance of gas flow from inside to the outside of MLI was evaluated in a steady state test, and was confirmed to take a value of the same level regardless of shape or size or pressure level when having the same perforation, spacer type, and attachment specification. In the depressurization test, MLI was observed as not inflating in a region of higher pressure even at higher depressurization speed, while inflating in a lower pressure region. The differential pressure between the inside and outside of MLI peaks when the level of pressure drops to about one kilo pascal or less. In addition, a simple mathmatical model of MLI inflation and venting is constructed and numerical simulations based on the model are conducted, which indicate that depressurization ratio (depressurization speed per the level of pressure) and volume of MLI are the dominantparameters. © 2012 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.
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41st International Conference on Environmental Systems AIAA-2011-518 2011年7月 筆頭著者
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20TH ESA SYMPOSIUM ON EUROPEAN ROCKET AND BALLOON PROGRAMMES AND RELATED RESEARCH 700 137-142 2011年A fully reusable sounding rocket is proposed in ISAS/JAXA. Vehicle systems and ground / flight operations are conceptually designed for observations of atmospheric phenomena, micro-gravity experiments and so on. The present design of the reusable sounding rocket is summarized. In phase A in the proposed reusable sounding rocket project, technical demonstrations for key technologies to develop the reusable sounding rocket are planed as follows; 1) reusable engine development and repeated engine operation development, 2) reusable insulation development for cryogenic tank, 3) aerodynamic design and flight demonstration for returning flight, 4) fuel/oxidizer management demonstration, 5) landing gear development and 6) health management system construction.
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日本伝熱シンポジウム講演論文集(CD-ROM) 48th 93-93 2011年 査読有り自励振動ヒートパイプの動作限界に関する理論を提案し、実験により検証を行っている。理論の概要は以下の通りである：自励振動ヒートパイプは圧力とボイド率の相互作用により、熱力学サイクルを構成し、このサイクルによって得られる仕事により、振動流が発生する。得られる仕事は圧力とボイド率の位相差が90度のときにもっとも高く、位相差が180度で仕事の発生はなくなる。位相差は流速が大きくなるとともに大きくなるので、流速には仕事の発生の低下による限界があり、これが自励振動ヒートパイプの作動限界となる。
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SPACE TELESCOPES AND INSTRUMENTATION 2010: ULTRAVIOLET TO GAMMA RAY 7732 2010年10月24日The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly successful X-ray missions initiated by the Institute of Space and Astronautical Science (ISAS). ASTRO-H will investigate the physics of the high-energy universe by performing high-resolution, high-throughput spectroscopy with moderate angular resolution. ASTRO-H covers very wide energy range from 0.3 keV to 600 keV. ASTRO-H allows a combination of wide band X-ray spectroscopy (5-80 keV) provided by multilayer coating, focusing hard X-ray mirrors and hard X-ray imaging detectors, and high energy-resolution soft X-ray spectroscopy (0.3-12 keV) provided by thin-foil X-ray optics and a micro-calorimeter array. The mission will also carry an X-ray CCD camera as a focal plane detector for a soft X-ray telescope (0.4-12 keV) and a non-focusing soft gamma-ray detector (40-600 keV) . The micro-calorimeter system is developed by an international collaboration led by ISAS/JAXA and NASA. The simultaneous broad bandpass, coupled with high spectral resolution of Delta E ~7 eV provided by the micro-calorimeter will enable a wide variety of important science themes to be pursued.
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40th International Conference on Environmental Systems AIAA-2010-6056 2010年7月
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40th International Conference on Environmental Systems AIAA-2010-6089 2010年7月
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Conference Record of the IEEE Photovoltaic Specialists Conference 1112-1117 2010年 査読有りThe Japan Aerospace Exploration Agency has been developing the Mercury Magnetospheric Orbiter (MMO), which is Japanese part of the BepiColombo mission. During its mission around Mercury, the spacecraft will be exposed to high solar irradiance of up to 11 suns, with an estimated maximum solar panel temperature of 230°C. In such an environment, solar cells are required to operate under high intensity and high temperature (HIHT) conditions. Therefore, it is necessary to evaluate the durability of solar cells to meet the power requirements throughout the mission life. We conducted a continuous operation test under HIHT conditions to examine the validity of the solar array configuration, using the interior planetary thermal vacuum chamber. Our HIHT tests clarified the following facts: (i) Transparency of the coverglass and the performance of the solar cells do not degrade and (ii) transparency of the DC93-500 adhesive in the top cell response region degrades mainly due to ultraviolet exposure at high temperatures. We decided to use AR0213 coverglass (from JDSU) with a thickness of 300 μm, which have a longer cut-on wavelength in ultraviolet region. With this configuration, the predicted decrease in Pmax due to the HIHT environment is 17.3% and that due to radiation effects is 11.0% Our new design will offer the available power at EOL of 394.2 W, which is 46.7 W greater than the required power. © 2010 IEEE.
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40th International Conference on Environmental Systems, ICES 2010 2010年 査読有りThis paper reports development of an experimental small LHP with PTFE wick. PTFE porous materials with 0.8 - 2.2 μm pore radius were fabricated and the basic properties were evaluated. An experimental small LHP with the PTFE wicks was designed and tested in an atmospheric condition. A PTFE wick with 1.2 μm pore radius was used to demonstrate the loop performance. The test results showed excellent operating characteristics of the LHP. © 2010 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.
書籍等出版物
1講演・口頭発表等
33-
46th International Conference on Environmental Systems 2016年7月
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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 2016年1月 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 2015年7月
所属学協会
5-
2020年9月
共同研究・競争的資金等の研究課題
10-
日本学術振興会 科学研究費助成事業 2023年4月 - 2027年3月
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日本学術振興会 科学研究費助成事業 2024年4月 - 2026年3月
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日本学術振興会 科学研究費助成事業 2023年4月 - 2026年3月
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日本学術振興会 科学研究費助成事業 基盤研究(B) 2018年4月 - 2021年3月
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日本学術振興会 科学研究費助成事業 挑戦的萌芽研究 2016年4月 - 2018年3月
産業財産権
6学術貢献活動
1-
パネル司会・セッションチェア等, 査読2003年7月 - 現在
● 指導学生等の数
6-
年度2018年度(FY2018)博士課程学生数1
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年度2019年度(FY2019)博士課程学生数2修士課程学生数1学術特別研究員数1
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年度2020年度(FY2020)博士課程学生数1修士課程学生数1学術特別研究員数1
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年度2018年度(FY2018)博士課程学生数1
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年度2019年度(FY2019)博士課程学生数2修士課程学生数1学術特別研究員数1
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年度2020年度(FY2020)博士課程学生数1修士課程学生数1学術特別研究員数1
● 専任大学名
2-
専任大学名東京大学（University of Tokyo)
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専任大学名東京大学（University of Tokyo)
● 所属する所内委員会
6-
所内委員会名研究所会議
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所内委員会名プログラム会議
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所内委員会名信頼性品質会議
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所内委員会名環境・安全管理統括委員会
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所内委員会名ISASニュース編集小委員会
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所内委員会名宇宙科学プログラム技術委員会
