• Title/Summary/Keyword: Single Column Injection Orifice

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Atomization Characteristics of the High Speed Rotating Injection System with Single Column Orifice (단열식 오리피스를 적용한 고속회전 분무노즐의 미립화 특성)

  • Jang, Seong-Ho;Choi, Seong-Man
    • Journal of ILASS-Korea
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    • v.14 no.3
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    • pp.97-102
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    • 2009
  • The spray characteristics of the high speed rotating fuel injection system were studied. The five variants of rotating fuel nozzle were used by spray test. The diameter of single column injection orifices are varied from 1 mm, 2 mm, 3 mm, 4 mm and 5 mm. We constructed high speed rotating test rig and measured droplet size by PDPA (Phase Doppler Particle Analyzer) system. Also spray was visualized by using high speed camera. In the test results, we could understand that length of liquid column from the injection orifice is mainly controlled by the rotational speeds. SMD is decreased with increasing injection orifice diameter and rotational speeds. Furthermore, from the comparison to the theoritical calculation, we confirmed that SMD is influenced by the liquid film thickness which is formed inner surface of injection orifice.

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A Study of Spray Characteristic with Orifice Diameter for Single Column Rotating Fuel Nozzle (단열식 회전연료 노즐의 오리피스 직경에 따른 분무특성 연구)

  • Jang, Seong-Ho;Choi, Seong-Man
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • pp.253-256
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    • 2009
  • In the micro turbojet engine less than 350kw power class, it is not easy to find out the good atomization fuel injector with good spray quality. However conceptually, rotating fuel injection system can give high atomization quality by only the centrifugal force of a high speed rotating shaft of the engine without high-pressure fuel pump. With this motivation, we manufactured very small rotating fuel injector of 40 mm diameter and performed under a variety of injection orifices. We measured droplet size, velocity and spray distribution by the PDPA(Phase Doppler Particle Analyzer) system. Also spray was visualized by using high speed camera. From the test results, we could understand that the length of liquid column from the injection orifice is mainly controlled by the rotational speeds. Furthermore, droplet size(SMD) is decreased with the rotational speeds and is influenced by the diameter of the injection orifice and liquid film thickness.

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Effect of Orifice Geometry on Flow Characteristics of Liquid Jet from Single Hole Nozzle (오리피스 형상에 따른 단공노즐 액체제트의 유동특성)

  • Song, Yoonho;Hwang, Donghyun;Ahn, Kyubok
    • Journal of the Korean Society of Propulsion Engineers
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    • v.21 no.5
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    • pp.19-28
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    • 2017
  • Effects of cavitation and hydraulic flip in circular and elliptical nozzles on the flow characteristics have been studied. Spray tests were conducted using injectors with different ratios of an orifice length(L) to a diameter(d) and of a major axis diameter(a) to a minor axis diameter(b). With the increment of an injection pressure drop, discharge coefficients slightly decreased in cavitation flows, and those suddenly dropped and were almost constant in hydraulic flip flows. For elliptical nozzles with L/b > 8 and L/a < 8, discharge coefficients and flow patterns showed different results from those in previous circular nozzles. When a flow in the elliptical nozzle was under steady condition, as the liquid column went downstream from the nozzle, its spray angle a little decreased in the plane of a major axis and increased in the plane of a minor axis.