丸 祐介

<p>JAXA has constructed an experimental facility to pressurize and supply liquid hydrogen at a maximum pressure of 90 MPa to conduct experimental research on the injection of high pressure liquid hydrogen into the atmosphere. Liquid hydrogen has a property that its density greatly changes depending on pressure despite being a liquid phase. In addition, the high pressure hydrogen gas is in a supercritical state and has an intermediate property between a gas and a liquid. Therefore, it is a difficult question whether to treat the injection of high pressure liquid hydrogen as a gas phase phenomena or as a liquid phase phenomena. As a result of the experiment, it was found good to apply the liquid orifice equation to predict the discharge flow rate of high pressure liquid hydrogen.</p>

<p>将来の火星着陸探査への適用を想定した超音速パラシュートのサブスケール模型の特性を，遷音速および超音速風洞実験で評価した．本稿では，風洞実験の方法と結果について紹介する．また，パラシュートの設計や検証における風洞実験の重要性についての，著者らの見解を述べる．風洞実験，数値解析と自由飛行実験を有機的に結合した，パラシュートの特性評価方法の必要性について議論する．</p>

<p>将来の火星着陸探査ミッションに必要となる超音速パラシュートを開発するために我々はキー技術として空力性能，構造性能，放出機構に大別し検証を行ってきた．まず遷音速風洞，超音速風洞試験を実施しマッハ2程度まで損傷なく安定に開傘できることを確認した．またより大きな模型を用いて大型低速風洞試験を実施し，火星等価動圧環境で損傷なく開傘できることを確認した．一方で抵抗係数に関して動圧が増加するにつれて減少することが確認されており，今後，流体構造連成解析を用いて検証を行っていく計画である．放出機構に関しては自動車用インフレータを用いる放出機構を提案し，能代ロケット試験場での大気圧環境下鉛直放出試験を実施しその妥当性を検証した．2016年10月には総合試験として大樹航空宇宙実験場にてヘリコプターからの投下試験を実施し自由飛行環境下における空力性能データを取得することができた．</p>

大気球シンポジウム 平成28年度（2016年11月1-2日. 宇宙航空研究開発機構宇宙科学研究所 (JAXA)(ISAS)）, 相模原市, 神奈川県資料番号: SA6000057016レポート番号: isas16-sbs-016

For landing a rover on the Mars ground, supersonic parachute has been developed in JAXA. Key technologies are categorized in aerodynamic performance, mechanical strength, ejection system, and validation method of the design for pre-flight model. So far, we have performed experiments in low-speed, transonic, and supersonic wind tunnels in Chofu aerospace center and ISAS. From these experiments, we have investigated aerodynamic performance such as drag coefficients, opening load factor, and stability of the parachute. We have also evaluated the mechanical strength in these wind tunnel tests. In addition, ejection system with automobile airbag inflator has been developed and a vertical ground test is performed in Noshiro Rocket Testing Center.

<p>In this paper, it is discussed, in order to apply wind tunnel testing results to design and validation of parachutes, whether characteristics of parachutes can be acquired and evaluated using sub-scale models in a wind tunnel testing in which size of a test model is strictly limited. Using Disk-Gap-Band (DGB) type parachutes, transonic and supersonic wind tunnel testing was conducted so that drag coefficient at steady state, unsteady vibration, and opening behavior and shock force at opening of parachutes. As a result, a series of characteristics of parachutes can be evaluated. On the other hand, the necessity of considering a physical similarity rule is emerged so as to apply the results from the wind tunnel testing to design of full-scale parachutes.</p>

<p>In this paper, leak detection system of hydrogen fuel in a future reusable rocket is examined. Identification of a leaking engine line is a fundamental requirement considering specifications and characteristics of the rocket system. Design of the leak detection system satisfying the requirement is examined. Specification of the detection system is examined through considering comprehensively causes of leaking in the rockets and evaluating the influences of those. Demonstration experiment of the identification function is conducted using full-scale mock-up model.</p>

<p>国立研究開発法人 宇宙航空研究開発機構（JAXA : Japan Aerospace Exploration Agency）宇宙科学研究所（ISAS : Institute of Space and Astronautical Science）の高速気流総合実験設備（風洞設備）はISAS/JAXAプロジェクトにおける高速飛翔体の開発研究に供されるとともに，全国の大学共同利用施設として学術研究にも広く利用され，国内における空気力学研究の拠点となっている．本稿では，ISAS/JAXAの風洞設備の概要と，ロケット開発，大気圏突入機開発，さらには将来の宇宙輸送システム研究や大学共同利用による空気力学，計測方法に関する研究など本設備にて得られたこれまでの成果，ならびに，今後の展望について述べる．</p>

A highly sensitive hydrogen gas sensor based on a fiber Bragg grating (FBG) has been developed. Various potential hydrogen sensor materials were screened by assessing the catalytic activities of oxide-supported platinum particles prepared by a sol-gel method. It was determined that a Pt/SiO2 film was the most appropriate sensor material; exposure of this film to 4 vol% H-2 in humid air for 30s at room temperature produced a temperature change of 65 K. In addition, the Pt/SiO2 was able to respond to a concentration as low as 0.1 vol% H-2 in dry air. Two types of sensor structures were fabricated and evaluated. The device incorporating a quartz glass substrate covered with the sensor film on one side was able to detect 0.4 vol% H-2 in dry air at room temperature with a response time of approximately 25 min. The other device, in which the sensor film was immobilized on the periphery of the FBG section, exhibited rapid response to 0.6 vol% H-2 within 20s. (C) 2014 Elsevier B.V. All rights reserved.

本論文では再利用型ロケット(RVT)用ワイヤレスヘルスモニタリングシステムにおける信号干渉について検証を行った。提案しているデュアルバンドWiCoPTシステムは25GHz帯のアップリンクによって高速データ伝送を行い,下り信号(5GHz)ではコマンドと無線電力伝送を行うという特徴を有している。今回は無線センサシムテム内で発生するアップリンクとダウンリンク間の信号干渉について検討を行った。その結果,無線センサヘルスモニタリングにステムにおいてICタグ内を回りこむFSK信号を0dBm以下,ICタグ送信機から受信機へ回りこむQPSK信号を-25dBm以下に抑えれば良いことを明らかにした。

平成26年度宇宙輸送シンポジウム（2015年1月15日-16日. 宇宙航空研究開発機構宇宙科学研究所（JAXA)(ISAS)）, 相模原市, 神奈川県資料番号: SA6000036026レポート番号: STCP-2014-026

A microgravity experiment system using a high altitude balloon has been developed. In order to accommodate payloads larger than previous system which employed three- dimensional drag-free control, one-dimensional drag-free control has been applied. The first test flight was conducted in Aug. 2014. A gravity level below 10(-3) G was obtained for more than 30 seconds during the free-fall of the capsule. A combustion experiment was conducted during the low gravity condition.

In this paper is presented a microgravity experiment system utilizing a high altitude balloon. The feature is a double shell structure of a vehicle that is dropped off from the balloon and a microgravity experiment section that is attached to the inside of the vehicle with a liner slider. Control with cold gas jet thrusters of relative position of the experiment section to the vehicle and attitude of the vehicle maintains fine microgravity environment. The design strategy of the vehicle is explained, mainly referring to differences from the authors' previous design. The result of the flight experiment is also shown to evaluate the characteristics of the presented system.

第58回宇宙科学技術連合講演会（2014年11月12日-14日. 長崎ブリックホール), 長崎市, 長崎県資料番号: AC1500062000レポート番号: JSASS-2014-4168

大気球シンポジウム 平成26年度（2014年11月6-7日. 宇宙航空研究開発機構宇宙科学研究所 (JAXA)(ISAS)）, 相模原市, 神奈川県資料番号: SA6000021007レポート番号: isas14-sbs-007

大気球シンポジウム 平成26年度（2014年11月6-7日. 宇宙航空研究開発機構宇宙科学研究所 (JAXA)(ISAS)）, 相模原市, 神奈川県資料番号: SA6000021011レポート番号: isas14-sbs-011

大気球シンポジウム 平成26年度（2014年11月6-7日. 宇宙航空研究開発機構宇宙科学研究所 (JAXA)(ISAS)）, 相模原市, 神奈川県著者人数: 18名資料番号: SA6000021014レポート番号: isas14-sbs-014

It is necessary to design the new concept of the space vehicles in order to survive the space market in the world. In previous paper (report 1), we suggest the new design method "Product and Operation design method" that can support concept design of space vehicles by many kinds of Products and Operations produced by orthogonal table. By using this new design method, we can compare two different types of Products (or Operations) in quantitatively, and we can get parameter area of Products and Operations that can meet the design requirements. Usually it is difficult to apply sensitivity analysis to cencept design phase, because engineers cannot define control factors and noise factors quantitatively. In this paper, we suggest a new sensitivity analysis method "Product and Operation sensitivity analysis method" that can be applied for concept design phase without defining control factors and noise factors. The prototype system based on this method is implemented, and some examples are shown.

It is necessary to design the new concept of the space vehicles in order to survive the space market in the world. However, although concept design is particularly important in space vehicle development to add value and reliability, it is difficult to apply conventional shape-based CAD/CAE systems to the concept design stage due to the lack of detailed design information at that stage. In this paper, we suggest the new design method (Product and Operation design method) that can support concept design of space vehicles by many kinds of Products and Operations produced by orthogonal table. By using this design method, we can design space vehicles in comparison with another design plans, and design the new space vehicles (e.g., multi-purpose space vehicles, or constellation satellites.). The prototype system based on the design method is implemented, and some examples applied for the concept design of super-sonic vehicle "SEED" are shown.

平成25年度宇宙輸送シンポジウム（2014年1月16日-17日. 宇宙航空研究開発機構宇宙科学研究所（JAXA)(ISAS)）, 相模原市, 神奈川県資料番号: SA6000016037レポート番号: STCP-2013-037

Design of an elliptical-to-rectangular transitioning hypersonic inlet for design Mach number of 5.0 is reviewed. The design approach that has been applied here is based on the streamline tracing technique in a known flowfield, where three-dimensional axisymmetric Busemann inlet is utilized as the flowfield to be modified. The choice of elliptical crosssectional capture and the desirable rectangular throat profile gives advantages in resolving simultaneously two major problems in the former flowfield without assistance of any other additional arrangements. The newly modified inlet provides reduction of approximately 80% in the contraction ratio and of 16.3% in the length of the compression surface.

本稿では,空気吸い込み式エンジンを用いた二段式スペースプレーンの実現に必要な要素およびシステム技術を飛行実証するための,科学実験気球を利用した飛行実験システムについて概説する.気球を利用することの利点としては,飛翔体の上昇がロケットによるそれよりも穏やかな機械環境においてなされ,必要なコストやオペレーションの煩雑さも比較的小さいことが挙げられる.本実験システムは,高速飛行する揚力飛翔体に必要な技術,例えば機体形状やエンジンの空気力学といった技術の獲得に貢献できるものである.

平成24年度宇宙輸送シンポジウム (2013年1月17日-1月18日. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)), 相模原市, 神奈川県形態: カラー図版あり形態: PDF資料番号: AA0061856060レポート番号: STCP-2012-060