• Title/Summary/Keyword: Swirl injector

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Combustion Characteristics of High Pressure Thrust Chamber with Single Coaxial Swirl Injector (이중와류 분사기를 적용한 고압 모델 연소기의 연소 특성 연구)

  • Seo, Seong-Hyeon;Lee, Kwang-Jin;Han, Yeoung-Min;Kim, Seung-Han;Kim, Jong-Gyu;Seol, Woo-Seok
    • 한국연소학회:학술대회논문집
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    • 2003.12a
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    • pp.131-136
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    • 2003
  • Experimental study on combustion characteristics of double swirl coaxial injectors has been conducted for the assessment of critical design parameters of injectors. A subscale thrust chamber has been fabricated with a water-cooled copper nozzle, which allows a chamber to be reused without replacing parts. Two different designs of injectors have been tested for the understanding of the effects of recess length on combustion. Clearly, the recess length drastically affects the combustion efficiency and hydraulic characteristics of the injector. Internal mixing of propellants in the injector with the recess number of two increases a combustion efficiency and reveals sound combustion although a pressure drop required for the similar amount of mass flow rates increases compared with the injector of the recess number of one.

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A Study on the Injection Characteristics of Swirl Nozzle Injector in Common-rail System for High Pressure Fuel Injection (커먼 레일 시스템 고압 연료 분사용 스월 노즐 인젝터의 분사 특성에 관한 연구)

  • Sin, Yunsub;Lee, Geesoo;Kim, Hyunchul;Kwak, Sangshin;Shin, Suk Shin;Suh, Hyun Kyu
    • Transactions of the Korean Society of Automotive Engineers
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    • v.21 no.4
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    • pp.89-95
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    • 2013
  • In this work, the evaluation of swirl nozzle injector performance was conducted by investigating effective area ($A_{eff}$), injection mass ($m_{inj}$), injection rate ($Q_{inj}$), and injection delay ($t_{delay}$) under various test conditions. To achieve these, fuel injection analysis system which was composed of fuel supply system, injection system, and control system was installed. At the same time, the swirl nozzle that had 12 orifice hole with $120^{\circ}$ injection angle was used in this work. It was revealed that the difference of injection mass ($m_{inj}$) between base and swirl nozzle injector increased as the injection pressure ($P_{inj}$) and energizing duration ($t_{eng}$) decreased under the same test conditions. The maximum injection rate ($Q_{inj}$) of swirl nozzle injector was higher than base nozzle injector about 2~5%. The injection performance of swirl nozzle was better than base nozzle at low injection pressure ($P_{inj}$) and short energizing duration ($t_{eng}$) conditions.

Study on the Dynamic Characteristics of Open Type Swirl Injector with Varyng Swirl Chamber Geometry (오픈형 스월 인젝터의 스월 챔버 형상 변화에 따른 동특성 연구)

  • Kim, Hyuntae;Chung, Yunjae;Jeong, Seokkyu;Yoon, Youngbin
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.43 no.7
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    • pp.619-625
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    • 2015
  • Swirl injectors are widely used for Liquid Rocket Engine(LRE) as fuel injection system and following researches are also being carried out throughout the world. Especially, solving combustion instability problem is essential for every type of LREs. In this study, cold test was carried out for open type swirl injector as a fundamental research to solve combustion instability problem. Pressure fluctuation was applied to the inlet flow coming into the injector and the following response characteristics were observed. The effect of swirl chamber geometry was also studied by changing both swirl chamber length and diameter.

Spray Characteristics of Swirl-coaxial Injector According to the Recess Length and Injection Pressure Variation (리세스 길이 및 분사압력 변이에 따른 스월 동축형 인젝터의 분무특성)

  • Bae, Seong Hun;Kwon, Oh Chae;Kim, Jeong Soo
    • Journal of the Korean Society of Propulsion Engineers
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    • v.20 no.4
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    • pp.68-76
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    • 2016
  • This research is carried out for the performance evaluation of the injector that is one of the critical components of bipropellant-rocket-engine. Spray characteristics are investigated in detail according to the recess length and injection pressure on the swirl-coaxial-injector using gaseous methane and liquid oxygen as propellants. A visualization is conducted by the Schlieren photography that is composed of a light source, concave mirrors, knife, and high-speed-camera. A hollow-cone-shape is identified in the liquid spray that is spread only by inner injector and the spray angle is decreased due to the diminution of swirl strength in accordance with the increase of the length of injector orifice. When the injector sprays the liquid through the inner injector with the aid of gas through the outer injector, the spray angle in external mixing region tends to increase with rise of the recess length, while in internal mixing region, it is decreased. It is also confirmed that the same tendency of the spray angle with recess length appears irrespective of the injection pressure of liquid spray.

The Effects of Operating Conditions and Injector Geometry on the Spray Characteristics of Swirl Injectors (스월 인젝터의 작동조건 및 인젝터 형상에 따른 분무특성)

  • Kim, D.J.;Im, J.H.;Han, P.G.;Yoon, Y.B.
    • Journal of ILASS-Korea
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    • v.9 no.1
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    • pp.21-29
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    • 2004
  • The flow characteristics of a swirl injector were investigated with the variation of the flow condition and geometric dimensions, such as orifice length for considering the viscous effect and tangential entry port area for considering the swirl intensity. The liquid film thickness strongly influencing on the formed drop size of the spray was measured using a new technique. The film thickness measurement technique proposed here, used the attenuation of fluorescence signal near the injector exit. The breakup length that is important for the flame location as well as the spray cone angle which influences on the ignition performance was measured using a backlit stroboscopic photography technique. From the experimental results, it is found that an increase in injection pressure decreased the film thickness and breakup length, and also enlarged the spray cone angle. A decrease in orifice length and tangential entry port area has a similar tendency of thinner film thickness, shorter breakup length and larger spray cone angle. In the present study, we proposed empirical models of the flow characteristics of the swirl injectors.

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Effects of Swirl/Shear-coaxial Injector on the Dynamic Behavior of Gaseous Methane-Gaseous Oxygen Diffusion Flame (스월/전단 동축형 인젝터가 기체메탄-기체산소 확산화염의 동역학적 거동에 미치는 영향)

  • Hong, Joon Yeol;Bae, Dae Seok;Kim, Jeong Soo
    • Journal of the Korean Society of Propulsion Engineers
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    • v.23 no.1
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    • pp.1-8
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    • 2019
  • To analyze the dynamic behavior and the structure of the gaseous methane-gaseous oxygen diffusion flame formed by a swirl/shear-coaxial injector, combustion experiments were carried out under different propellant injection conditions. As a result, the OH radical emission intensity of the diffusion flame visualized through chemiluminescence was observed to increase as the propellant mass flow and the momentum flux ratio increased. And flames with swirl showed a more high radical emission intensity than those without swirl.

A Study on Dynamic Characteristics of Gas Centered Swirl Coaxial Injector with Acoustic Excitation by Varying Momentum Flux Ratio (운동량 플럭스 비의 변화에 따른 기체 중심 스월 동축형 분사기의 기체 가진 동특성 연구)

  • Lee, Jungho;Park, Gujeong;Yoon, Youngbin
    • Journal of ILASS-Korea
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    • v.20 no.3
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    • pp.168-174
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    • 2015
  • Combustion instability is critical problem in developing liquid rocket engine. There have been many efforts to solve this problem. In this study, the method was sought through the injector as part of these efforts to suppress combustion instability. If the injector can suppress the disturbance coming from the supply line as a kind of buffer it will serve to reduce combustion instability. Especially we target at gas propellant oscillation in gas-centered swirl coaxial injector. The phenomenon is simulated with acoustic excitation of speaker. The film thickness response at injector exit was measured by using a liquid film electrode. Also the response of spray to the disturbance was observed by high-speed photography. Gas-liquid momentum flux ratio and the frequency of feeding gas oscillation were changed to investigate the effect of these experimental parameters. The trend of response by varying these parameters and the cause of weak points was studied to suggest the better design of injector for suppressing combustion instability.

A Study on Dynamic Characteristics of Gas Centered Swirl Coaxial Injector Varying Tangential Inlet Diameter with Liquid Pulsation (기체 중심 동축형 분사기의 접선방향 유입구 지름 변화에 따른 액체 가진 연구)

  • Oh, Sukil;Park, Gujeong;Kim, Seongju;Lee, Hyeongwon;Yoon, Youngbin;Choi, Jeong-Yeol
    • Journal of ILASS-Korea
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    • v.22 no.2
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    • pp.62-68
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    • 2017
  • It is important to study on the combustion instability to develop liquid rocket engines for preventing lower combustion efficiency and destruction of combustion chamber. There are many researches on simplex injector with liquid pulsation to solve this problem. In real rocket engine system, however, they use coaxial injectors. Therefore, research on coaxial injector with liquid pulsation is essential. In this study, we investigate dynamic characteristics of gas centered swirl coaxial injector varying tangential inlet diameter. A mechanical pulsator was used to generate an excitation in the liquid flow, and the response characteristics of the injector were confirmed. As tangential inlet diameter increased, mass flow rates increased and spray angle decreased. As tangential inlet diamter decreased, gain decreased because the pressure fluctuation in the injector manifold rarely passed through the inlet. Additionally, it was confirmed that a sufficiently small tangential inlet served as a damper.

Experimental Investigation for Multi-Element Dual Swirl Coaxial Injector (다중요소 Dual Swirl 인젝터에 관한 실험적 연구)

  • Shin, Hun-Cheol;Lee, Seock-Chin;Park, Hee-Ho;Kim, Sun-Jin
    • Journal of the Korea Institute of Military Science and Technology
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    • v.9 no.4
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    • pp.137-144
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    • 2006
  • The basic data obtained in this research for single element performance were directly applied to the design of injector head(7 elements). Designed performance of the 7-element Swirl Coaxial injector was $245kg_f$ sea level thrust with 20bar combustion chamber pressure. Numerical analysis were performed to obtain the change of spray pattern for the design of injector head, and we confirmed the feasibility and application of those results. Hot tests were performed for the multi-element injector to compare with the performance of the single element injector and those can be applied to the design of scaled liquid rocket engine. The basic data obtained in this research can be directly applied to the real liquid rocket injector design.

Development of Sub-scale Combustor for a Liquid Rocket Engine Using Swirl Injector with External Mixing (외부혼합 와류분사기를 장착한 액체로켓엔진용 축소형 연소기 개발)

  • Han, Yeoung-Min;Kim, Seung-Han;Seo, Seong-Hyeon;Lee, Kwang-Jin;Kim, Jong-Gyu;Seol, Woo-Seok
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.32 no.10
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    • pp.102-111
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    • 2004
  • The procedure of design and manufacture of sub-scale combustor using bipropellant swirl injector with external mixing for a liquid rocket engine are described. The results of cold flow test, ignition test and combustion test of the sub-scale combustor are also given in this paper. The sub-scale combustor uses liquid oxygen(LOx) and kerosene as propellants and has a injector head, an ablative material combustor wall and a water cooled nozzle. The injector head has LOx manifold, fuel manifold, fire face plate, one center swirl injector and 18 main swirl injectors. The cold flow, ignition and combustion tests were successfully performed without damage of combustor. Results of hot firing tests show that combustion efficiency meets the target of design and operations of start and stop cyclogram are stable and high frequency combustion instability does not occur.