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

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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

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

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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

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.