著者

榊 和樹 角銅 洋実 中谷 辰爾 津江 光洋 五十地 輝 鈴木 恭兵 牧野 一憲 平岩 徹夫

出版者

一般社団法人 日本航空宇宙学会

雑誌

日本航空宇宙学会論文集 (ISSN:13446460)

巻号頁・発行日

vol.63, no.6, pp.271-278, 2015 (Released:2015-12-05)

参考文献数

20

被引用文献数

1

---

The pintle injector is one of the most promising candidate for propellant injection systems of liquid rocket engine combustors due to the throttling capability and simple structure. However, combustion characteristics of pintle injectors are still unclear. Therefore, combustion experiments are conducted for an ethanol/liquid oxygen rocket engine combustor with a planar pintle injector which simulates the injection configuration of a pintle injector and enables optical measurements at Pc=0.40MPa and O/F=1.08-1.56. Direct images of the flame structure and CH chemiluminesence are observed through an optical window using high speed imaging techniques. Backlit images of the spray structure are observed. Strong CH chemiluminescence is observed in the vicinity of the impinging point of the two propellants. Luminous flames are observed in the vicinity of the faceplate and the upper wall of the combustor. It is observed that atomization process of the planar pintle injector proceeds two-dimensionally unlike conventional impinging injectors. A periodic atomization behavior is observed with the frequency of approximately 700Hz, being equal to the frequency of the Kelvin-Helmholtz instability.

著者

平岩 徹夫 Hiraiwa Tetsuo

出版者

宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)

雑誌

平成25年度宇宙輸送シンポジウム: 講演集録 = Proceedings of Space Transportation Symposium FY2013

巻号頁・発行日

2014

---

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

著者

榊 和樹 舩橋 友和 中谷 辰爾 津江 光洋 金井 竜一朗 鈴木 恭兵 稲川 貴大 平岩 徹夫

出版者

一般社団法人 日本航空宇宙学会

雑誌

日本航空宇宙学会論文集 (ISSN:13446460)

巻号頁・発行日

vol.65, no.5, pp.193-199, 2017

---

The longitudinal combustion instability characteristics of a pintle-type injector for a bipropellant rocket engine combustor are investigated experimentally. An optically accessible combustion chamber are used to observe unsteady combustion behaviors under oscillating combustion conditions. CH* chemiluminescence and backlit spray images are observed simultaneously with two high-speed cameras. Two experiments with the propellant total momentum ratio (TMR) of 0.76 and 2.48 are conducted, whereas the combustion pressure and the propellant mixture ratio are 0.45 and 1.6, respectively. The combustion oscillations at the natural frequencies of the chamber longitudinal acoustic mode are observed when the TMR is 0.76. The combustion oscillation is caused by the coupling between the heat release and the combustion chamber acoustics. When the TMR is 2.48, the combustion oscillations at the frequencies of 400 and 800Hz, which are lower than the first longitudinal mode frequency, are observed. Since the 400Hz corresponds to the convective time scale in the combustion chamber, the oscillations could be caused by one of the convective modes such as entropy wave.

著者

角銅 洋実 榊 和樹 中谷 辰爾 津江 光洋 金井 竜一郎 稲川 貴大 平岩 徹夫

出版者

一般社団法人 日本航空宇宙学会

雑誌

日本航空宇宙学会論文集 (ISSN:13446460)

巻号頁・発行日

vol.65, no.1, pp.1-9, 2017

---

The pintle injector is a promising candidate for injection systems of future rocket engines because of the throttling capability, the combustion stability, and the low manufacturing cost. Few studies focusing on fundamental aspects of a pintle injector have been conducted, and most of the design parameters of a pintle injector is determined mainly based on the empirical knowledge. Among the design parameters, total momentum ratio (TMR) is one of the most important parameters since spray structure is dominated by TMR. Therefore, combustion experiments using an ethanol/liquid oxygen rocket engine combustor with a planar pintle-type injector which is designed for optical measurements for a pintle injector are conducted at combustion pressure (<I>P_c</I>) = 0.37-0.42MPa, mixture ratio (O/F) = 1.31-1.49, TMR = 0.32-3.65 to investigate the effects of propellant momentum ratio on the combustion behavior. The spray structure under hot fire conditions is observed using high-speed imaging techniques with a backlit configuration. In the oxidizer-centered configuration, the characteristic exhaust velocity efficiency (<I>η<SUB>C</SUB><SUP>*</SUP></I>) decreases with the increase of the TMR. The atomized propellant impinge on the combustor wall before the vaporization and reaction at higher TMR. In the fuel-centered configuration, though the propellant spray is more inclined to the direction of the upper combustor wall at higher TMR, the <I>η<SUB>C</SUB><SUP>*</SUP></I> does not change with the TMR. In both oxidizer-centered and fuel-centered, higher <I>η<SUB>C</SUB><SUP>*</SUP></I> is provided in the condition of higher injection pressure drop.

著者

河内 俊憲 三谷 徹 平岩 徹夫 富岡 定毅 升谷 五郎

出版者

一般社団法人 日本航空宇宙学会

雑誌

日本航空宇宙学会論文集 (ISSN:13446460)

巻号頁・発行日

vol.51, no.595, pp.403-411, 2003 (Released:2003-09-26)

参考文献数

15

被引用文献数

2 6

---

A one-dimensional theoretical method for an evaluation of the net thrust of a scramjet engine is presented. To calculate the thrust performance of the engine analytically, an efficiency characterizing compression process, such as recovery factor in total pressure or kinetic energy efficiency etc., is necessary. In the previous theoretical method, this efficiency was roughly assumed. Although the effect of aerodynamic parameters and configuration parameters on the thrust can be investigated with this rough assumption, the net thrust evaluated with this method was not enough accurate to be compared with the measured thrust in experiments. The total pressure loss is chosen as the efficiency in this paper. This total pressure loss is evaluated from the engine internal drag with the wind tunnel experiment, which is due to irreversible process through the engines. The theoretical maximum thrust of the engines can be calculated with this new method.

著者

榊 和樹 角銅 洋実 中谷 辰爾 津江 光洋 五十地 輝 鈴木 恭兵 牧野 一憲 平岩 徹夫

出版者

一般社団法人 日本航空宇宙学会

雑誌

日本航空宇宙学会論文集 (ISSN:13446460)

巻号頁・発行日

vol.63, no.6, pp.271-278, 2015

---

The pintle injector is one of the most promising candidate for propellant injection systems of liquid rocket engine combustors due to the throttling capability and simple structure. However, combustion characteristics of pintle injectors are still unclear. Therefore, combustion experiments are conducted for an ethanol/liquid oxygen rocket engine combustor with a planar pintle injector which simulates the injection configuration of a pintle injector and enables optical measurements at <I>Pc</I>=0.40MPa and O/F=1.08-1.56. Direct images of the flame structure and CH chemiluminesence are observed through an optical window using high speed imaging techniques. Backlit images of the spray structure are observed. Strong CH chemiluminescence is observed in the vicinity of the impinging point of the two propellants. Luminous flames are observed in the vicinity of the faceplate and the upper wall of the combustor. It is observed that atomization process of the planar pintle injector proceeds two-dimensionally unlike conventional impinging injectors. A periodic atomization behavior is observed with the frequency of approximately 700Hz, being equal to the frequency of the Kelvin-Helmholtz instability.

著者

村上 淳郎 工藤 賢司 平岩 徹夫 鎮西 信夫 苅田 丈士

出版者

宇宙航空研究開発機構

雑誌

宇宙航空研究開発機構研究開発報告 (ISSN:13491113)

巻号頁・発行日

vol.4, pp.1-18, 2005-03

---

水冷スクラムジェット燃焼器の自発着火燃焼性能を、空気総圧、空気総温、燃焼器長さ、壁温そして燃料噴射型式をパラメータとして調べた。水冷スクラムジェット燃焼器には、マッハ数2.5、空気総圧1.0, 1.5, 2.0 MPa、空気総温1200〜2600 K の高温模擬空気が流入する。高温模擬空気は水冷式の高温模擬空気発生装置(VAG)で生成した。水冷スクラムジェット燃焼器は、超音速ノズルを有する水冷スクラムジェット燃焼器試験装置に直結した。燃焼状態は燃焼器内の温度上昇により調べた。燃料垂直噴射時の自発着火性能は、空気総圧が増加すると着火限界空気総温が高くなる傾向にあった。この条件は第2限界付近であった。空気中のH_2O の存在は、高い空気総圧のときに更に着火を遅らせた。空気総温が高い状態では、圧力の上昇によって自発着火性能は改善された。燃焼器が長くなったときの自発着火性能は、垂直噴射では向上した。しかしその度合いは、空気総圧が高くなるほど小さくなった。平行噴射では、自発着火性能は低かった。水冷スクラムジェット燃焼器の着火限界空気総温は、無冷却スクラムジェット燃焼器より高かった。これより着火源は、剥離領域等の燃焼器壁面付近に存在すると考えられた。