• Title/Summary/Keyword: 분사 액체

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Effects of Injector Recess and Combustion Chamber Length on Combustion Stability of Swirl Coaxial Injectors (동축 와류형 분사기의 연소안정성에 대한 분사기 리세스 및 연소실 길이의 영향)

  • Bak, Sujin;Hwang, Donghyun;Ahn, Kyubok;Yoon, Youngbin
    • Journal of the Korean Society of Propulsion Engineers
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    • v.24 no.1
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    • pp.24-33
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    • 2020
  • In this study, model combustion tests were conducted to investigate the combustion instability characteristics of swirl coaxial injectors for a liquid rocket engine. To examine the effects of the combustion chamber resonant frequency and the injector mixing conditions, pressure fluctuations in the combustion chamber were measured by changing the combustion chamber length, injector recess length, and propellant mixture ratio. From the test results, the variation in the pressure fluctuations for each experimental condition was confirmed and the combustion stability was evaluated by stability mapping. It was found that the longitudinal mode and Kelvin-Helmholtz instabilities occurred due to the change in the combustion chamber and recess lengths.

Numerical Study on the CO and NO of Rocket Plume as the Type of Water Injection in the Flame Guiding Duct (화염유도로 냉각수 분사방식에 따른 로켓 플룸의 CO와 NO 반응의 수치해석)

  • Kim, Seong-Lyong;Kim, Seung-Han;Han, Yeoungmin
    • Journal of the Korean Society of Propulsion Engineers
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    • v.19 no.3
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    • pp.39-46
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    • 2015
  • A numerical study has been conducted on CO after burning and NO generation of the rocket plume as the cooling water injected to the rocket plume. The present study shows that the cooling water has a role of increasing the degree of CO after burning and reducing NO generation. However the effect varies as the injection configuration of the cooling water. When the cooling water is injected at the side of the plume, NO generation is dramatically reduced while the degree of CO after burning is relatively low. When the cooling water is injected at the side and the center of the plume, CO after burning is highly increased and NO generation is also dramatically reduced.

A Study on the Interaction Effect Between Spray Fan Formed by Gas/Liquid Swirl Injector (기체/액체를 사용하는 Swirl 인젝터의 간섭효과에 관한 연구)

  • Joung, Rae-Hyuck;Kim, Yoo;Cha, Young-Ran;Park, Joung-Bae;Park, Uoo-Dong
    • Journal of the Korean Society of Propulsion Engineers
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    • v.1 no.1
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    • pp.1-7
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    • 1997
  • Experimental study was carried out to investigate the interaction effect between spray fan formed by gas/liquid swirl injector. Test variables were supply pressure and injector distance. Water and air were the simulant for the experiment. For water supply only; Collected water mass was concentrated at the lower part of the two spray fan, but this effect was reduced with increasing supply pressure. Both air and water supply1; Collected water mass was again concentrated at the lower part of the impingement point, but this effect was reduced when air/water supply pressure ratio was increased.

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Study on the Performance of Small Size Liquid Rocket Engine (축소형 엔진의 성능에 관한 연구)

  • Namkoung Hyuck-Joon;Han Poong-Gyoo;Kim Dong-Hwan;Lee Kyoung-Hoon;Kim Young-Soo
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • v.y2005m4
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    • pp.139-143
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    • 2005
  • Combustion Test Facility for Liquid Rocket Engine using kerosene and liquid oxygen has been developed for the purpose of cooling and performance study. Test engine of thrust 0.5 KN(design thrust) is tested to confirm the normal operation. Therefore, water-cooled firing tests using kerosene engine with injectors of fuel-centered coaxial type are conducted. With the viewpoint of characteristic velocity, and specific impulse at sea level, and chamber pressure on OF mixture ratio are analyzed.

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Ignition and Extinction Characteristics of a Low Thrust Combustion Chamber using Green Propellant according to Sequence of the Combustion Test (친환경 추진제를 사용하는 저추력 액체로켓엔진의 연소시험 시퀀스에 따른 점화 및 소염 특성)

  • Kim, Young-Mun;Jeon, Jun-Su;Choi, Yu-Ri;Ko, Young-Sung;Kim, Yoo;Kim, Sun-Jin
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2009.11a
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    • pp.130-133
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    • 2009
  • The sequence of the propellant supply is very important for the reliable and safe operation of a LRE combustion test. So combustion performance tests were performed to find an optimum test sequence by changing supply time of propellants and purge gas in the moment of ignition and extinction. The liquid rocket engine consisted of a catalytic ignitor and six swirl-coaxial injectors which used hydrogen peroxide and kerosene. Conclusively, an optimum sequence was found for stable combustion in the moment of ignition and extinction.

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Basic Design of Combustion Chamber for 75 ton Liquid Rocket Engine (75톤급 액체로켓엔진 연소기 기본설계)

  • Han, Yeoung-Min;Kim, Jong-Gyu;Lee, Kwang-Jin;Seo, Seong-Hyeon;Kim, Seong-Ku;Ryu, Chul-Sung;Choi, Hwan-Seok
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2009.11a
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    • pp.125-129
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    • 2009
  • The basic design of liquid rocket engine combustion chamber for a large space launch vehicle was described. It has vacuum thrust of 74.8 ton, vacuum specific impulse of 306.9 sec, chamber pressure of 60 bar, mass flow rate of 243.6 kg/s and combustion characteristic velocity of 1730 m/sec. The details of combustion performance and geometrical parameter were also given. The 75 ton combustion chamber consists of the combustor head with injector and the chamber/nozzle with regenerative cooling channels.

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Development of Real-Fluid Package Compatible with Chemkin for High-Pressure Kerosene/LOx Combustion (케로신/액체산소의 고압 연소해석을 위한 열역학/전달 물성치 해석 패키지 개발)

  • Kim, Seong-Ku;Choi, Hwan-Seok
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2011.04a
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    • pp.89-92
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    • 2011
  • The modeling of thermodynamic non-idealities and transport anomalies is a crucial prerequisite to realistically simulate the mixing and combustion processes of liquid propellants injected above critical pressures. This study has developed a specific set of subroutines to calculate the thermodynamic and transport properties based on the generalized cubic equation of state (EoS) in a coupled manner with the standard chemical kinetics packages (Chemkin). The existing flamelet analysis code is extended with the real-fluid package and applied to numerical investigation of local flame structures of kerosene and liquid oxygen at high pressure conditions relevant to the actual rocket engines.

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축소 노즐에서의 슬롯 막냉각 열전달 특성에 관한 연구

  • 조용일;조형희
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2000.04a
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    • pp.33-33
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    • 2000
  • 고온의 연소가스로부터 노즐 표면을 보호하기 위하여 슬롯을 통하여 냉각 유체를 분사하는 슬롯 막냉각에 대하여 연구하였다. 냉각효율 및 열전달 특성은 주유동과 2차 유동의 분사율에 따라 크게 달라지며, 형상변화 및 유동가속에 의해서도 냉각 효과의 변화를 가져오게 된다. 따라서 본 연구에서는 실험을 통하여 면적비가 16:1인 축소노즐에서 압축성 효과를 배제할 수 있는 유동속도 범위 내에서 분사율 변화(0.5 $\leq$ M $\leq$ 3.0)에 따른 슬롯 막냉각 열전달 특성을 고찰하고, 평판 슬롯 막냉각 경험식의 결과와 비교하였으며, 수치해석을 통하여 축소노즐과 원형관에서의 냉각효율 및 열전달 특성을 비교함으로서 이를 검증하였다. 축소노즐에서의 슬롯 막냉각 열전달 특성은 단열벽면조건을 형성하여 노즐 표면을 따라 설치된 열전대를 이용하여 측정하였다. 그 결과 상대적으로 낮은 분사율(M=0.5, 1.0)에서 분사율 증가에 따른 냉각효율의 증가가 크게 나타났으며, 분사율이 높아짐(M $\geq$ 2.0)에 따라 냉각효율의 증가폭이 점점 감소하고, 일정 분사율 이상에서는 냉각 효율의 증가가 크게 둔화되었다. 분사율이 낮을 경우 평판 슬롯 막냉각 경험식으로 주어진 결과보다 상류에서는 높으나 하류로 진행하면 비슷한 냉각효율을 보였고, 분사율이 높은 경우 평판보다 전 범위에서 약간 높은 냉각효율을 나타냈다. 수치해석 결과에서는 분사율이 낮을 경우 축소노즐의 냉각효율이 원형관에서의 냉각효율 보다 낮거나 비슷하게 나타났으며, 분사율이 높아짐에 따라 축소노즐에서의 냉각효율이 오히려 높아지는 것으로 나타났다.타내었다. 액체 제트의 속도는 처음에는 일정하게 유지되다가 운동량을 보존하기 위해 가스로부터 운동량을 받아 점차 가속되어지는 것으로 나타났다.본 규격은 키, 총장, 어깨길이, 등길이, 머리길이, 머리둘레, 진동둘레, 목둘레, 가슴둘레, 허리둘레, 배둘레, 엉덩이둘레, 앞품, 뒤품, drop치를 포함하고 있고, 각 규격에서 호칭간 치수 간격도 함께 제시하고 있다. 본 연구 결과에서 보듯, 현행 8규격의 무진복의 각 호칭간 적정 허용범위를 고려해 합리적인 치수체계를 정립한다면 치수에 대한 적합도가 상당히 증가할 뿐 아니라 생산비용도 상당히 감축할 것으로 생각된다.나타났다. 4) 호감적 서비스능력 차원에서 세 독립변수간에 유의한 3원 상호작용이 존재하는 것으로 나타나( $F_{2,228}$=15.62, P<.001) 20대에 적합한 의복 착용시( $F_{2,228}$=3.98, P<.05)와 60대에 적합한 의복 착용시( $F_{2,228}$=16.55, P<.001) 점포유형과 격식차림간에는 유의한 상호작용이 존재하는 것으로 나타났다. 5) 호감을 구성하는 세 요인들이 구매의도에 미치는 영향을 조사한 결과 호감적 인상차원은 29%(P<.001), 호감적 서비스능력차원은 6%(P<.001)의 구매의도를 설명해 주는 것으로 나타났다. 본 연구결과 노년 소비자에게 호감을 주는 판매원의 외모는 구매의도에 영향을 주어 실버의류산업의 이익증대와 밀접한 연관을 갖는 서비스품질의 중요한 요인으로 밝혀졌다.중요한 요인으로 밝혀졌다.로운 단백질 EPSPS가 다른 여러 식물에 이미 존재하고 있는 단백질로서 우리가 이미 이러

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Study on the Dissolution Behavior of Liquide $CO_2$ Hydrate Injected at the Intermediate Depth of the Ocean (중층심해에 분사된 액체 이산화탄소 하이드레이트 용해에 대한 연구)

  • Kim, Nam-Jin;Park, Sung-Seek;Seo, Hyan-Min
    • New & Renewable Energy
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    • v.4 no.2
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    • pp.12-20
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    • 2008
  • Calculations for the dissolution behavior of liquid CO2 droplets released in the East Sea and the Clipperton Clarion from a moving ship and a fixed pipeline have been carried out in order to estimate the CO2 dissolution characteristics in the ocean. The results show that the injection of liquid CO2 from a moving ship in a high temperature point is an effective method for dissolution. Also, it is noted that the ultimate plume generated from CO2 bubbles repeatsand shrinking due to the peeling from a fixed pipeline, and the presence of hydrate layer on a liquid CO2 droplet acts as a resistant layer in dissolving liquid CO2.

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Study on Spray Angle of a Throttleable Pintle Injector according to Total Momentum Ratio based on Hot Fire Test Conditions (연소시험 조건 기반 총운동량비에 따른 가변추력 핀틀 분사기의 분무각 분석)

  • Heo, Subeom;Kim, Dae Hwan;Lee, Suji;Yoon, Youngbin
    • Journal of ILASS-Korea
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    • v.25 no.3
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    • pp.126-131
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    • 2020
  • Throttleable rocket engines are in high demand due to the diversification of space missions. Pintle injector is known to be suitable for throttleable rocket engines, because of its high efficiency in overall thrust zone. In this study, the relationship between spray angle of a throttleable pintle injector and total momentum ratio based on hot fire test conditions was investigated. As a result, the spray angle in 100% and 60% throttling level is higher than the spray angle obtained by the case which considers only propellant mass flow rate, owing to higher total momentum ratio (TMR). The results of this study may be useful for predicting spray angle in hot fire test.