• 제목/요약/키워드: Axial Injection

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스월 인젝션 하이브리드 로켓의 고체연료 국부 후퇴율에 관한 연구 (A Study on the Local Regression Rate of Solid Fuel in Swirl Injection Hybrid Rocket)

  • 김수종;이정표;김기훈;조정태;문희장;성홍계;김진곤
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2008년도 제30회 춘계학술대회논문집
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    • pp.77-81
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    • 2008
  • 스월 인젝션 하이브리드 로켓의 고체연료에서 축 방향 국부 후퇴율 거동을 고찰하였다. 일반적으로 축 인젝션 후퇴율은 연료 그레인 축 위치가 입구에서 멀어질수록 감소하다가, 다시 증가하는 경향을 보인다. 이에 반해 스월 인젝션 후퇴율은 연료 입구부에서 높고, 하류에서는 비교적 균일한 후퇴율을 보임을 확인하였다. 전체 후퇴율은 스월 인젝션의 경우가 축 인젝션의 경우에 비해 54% 증가하였다. 본 연구를 통해 소형 사운딩 로켓에서 스월 인젝터를 사용하는 것이 유용할 수 있음을 확인하였다.

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역스월 유로 입력을 가지는 밸런스 슬리브를 적용한 고압 다단 펌프의 진동 특성 (Vibration Characteristics of High Pressure Multi-Stage Pump with Anti-Swirl Injection Balance Sleeve)

  • 곽현덕;이용복;김창호;이봉주
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2002년도 춘계학술대회논문집
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    • pp.214-219
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    • 2002
  • As the tangential flow inside the clearance of tribe elements such as bearings and seals is increased as the shaft speed increases, the system stability will be decreased due to the increment of the instability parameter. To reduce the tangential flow inside the clearance of the balance sleeve, anti-swirl injection mechanism is applied. The balance sleeve is used in resisting the axial force induced by impeller in high pressure multi-stage pump. In this paper, total three cases are experimentally investigated; original balance steeve, anti-swirl injection balance steeve with 0 axial degree and anti-swirl injection balance sleeve with 30 axial degree. Experiments are focused in the comparison of vibration level and leakage flow rate. The results clearly shows that the anti-swirl injection balance sleeve with 0 axial degree improves the vibration characteristics. However, the anti-swirl injection balance sleeve with 30 degree aggravates the vibration characteristics. In the standpoint of leakage performance, both anti-swirl injection balance sleeves show the better result than the original balance sleeve.

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역스월 유로 입력을 가지는 밸런스 슬리브를 적용한 고압 다단 펌프의 진동 특성 (Vibration Characteristics of High Pressure Multi-stage Pump with Anti-swirl Injection Balance Sleeve)

  • 곽현덕;이용복;김창호;이봉주
    • 한국소음진동공학회논문집
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    • 제12권8호
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    • pp.632-638
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    • 2002
  • As the tangential flow inside the clearance of tribo elements such as bearings and seals is increased as the shaft speed increases, the system stability will be decreased due to the increment of the instability parameter. To reduce the tangential flow inside the clearance of the balance sleeve, anti-swirl injection mechanism is applied. The balance sleeve is used in resisting the axial force induced by impeller in high pressure multi-stage pump. In this paper, total three cases are experimentally investigated; original balance sleeve, anti-swirl injection balance sleeve with 0 axial degree and anti-swirl injection balance sleeve with 30 axial degree. Experiments are focused in the comparison of vibration level and leakage flow rate. The results clearly shows that the anti-swirl injection balance sleeve with 0 axial degree improves the vibration characteristics. However, the anti-swirl injection balance sleeve with 30 degree aggravates the vibration characteristics. In the standpoint of leakage performance, both anti-swirl injection balance sleeves show the better result than the original balance sleeve.

대형 액상분사식 LPG 엔진의 희박연소특성에 관한 연구 (Lean Burn Characteristics in a Heavy Duty Liquid Phase LPG Injection SI Engine)

  • 오승묵;김창업;강건용;우영민;배충식
    • 한국자동차공학회논문집
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    • 제12권4호
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    • pp.1-11
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    • 2004
  • Combustion and fuel distribution characteristics of heavy duty engine with the liquid phase LPG injection(LPLI) were studied in a single cylinder engine, Swirl ratio were varied between 1.2, 2.3, and 3.4 following Ricardo swirl number(Rs) definition, Rs=2.3 showed the best results with lower cycle-by-cycle variation and shorter burning duration in the lean region while strong swirl(Rs=3.4) made these worse for combustion enhancement. Excessive swirl resulted in reverse effects due to high heat transfer and initial flame kernel quenching. Fuel injection timings were categorized with open valve injection(OVI) and closed valve injection(CVI). Open valve injection showed shorter combustion duration and extended lean limit. The formation of rich mixture in the spark plug vicinity was achieved by open valve injection. With higher swirl strength(Rs=3.4) and open valve injection, the cloud of fuel followed the flow direction and the radial air/fuel mixing was limited by strong swirl flow. It was expected that axial stratification was maintained with open-valve injection if the radial component of the swirling motion was stronger than the axial components. The axial fuel stratification and concentration were sensitive to fuel injection timing in case of Rs=3.4 while those were relatively independent of the injection timing in case of Rs=2.3.

하이브리드 로켓에서의 고체연료의 국부 후퇴율에 관한 연구 (A Study on the Local Regression Rate of Solid Fuel in Hybrid Rocket)

  • 김수종;이정표;김기훈;조정태;김학철;우경진;문희장;성홍계;김진곤
    • 항공우주시스템공학회지
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    • 제2권4호
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    • pp.1-6
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    • 2008
  • In generally, the regression rate was expressed with average value and oxidizer mass flux in hybrid propulsion system. This can not represent the local value of regression rate along with oxidizer flow direction. In this study, experimental studies were performed with Separation method and Cutting method for measure local regression rate. In axial injection, the local regression rate decreases rapidly with axial location near entrance and increases with axial direction from the leading edge and the empirical formula for local regression rate with function of oxidizer mass flux and location was derived. Swirl injection regression rate has higher value at the leading edge of the fuel and comparatively uniform regression rate at the downstream. Overall regression rate of swirl injection is higher increased about 54 % than regression rate of axial injection.

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Design Study of an Axial Injection System for MC50 Cyclotron at KIRAMS

  • Kim, Jae-Hong;Cho, Sung-Jin;Choi, Jun-Yong;Hong, Seung-Pyo;Yu, In-Gong;Park, Hyun;Lee, Ji-Sup
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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    • pp.262-262
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    • 2012
  • A multi-purpose cyclotron, MC50 has been operated to provide multi-ions of proton, deuteron and alpha at Korea Institute of Radiological and Medical Sciences (KIRAMS). Neutron is also produced through the (p,n) nuclear process with a Be target. However, a wide spectrum of current of ions is requested by beam users for carrying their various application fields. Therefore a simulation study is requested on the design of an axial injection system for high current proton and alpha beam extraction for radio-isotope productions and scientific researches. The purpose of this study is seeking a relatively simple method for the MC50 having higher alpha beam capability and also improving proton and deuteron beams currently used. We are considering two possibilities to improve the internal ion source and to install a new external axial injection system. The external injection system will be consisted of an Einzel lens, a steering magnet, a buncher, and a glazer lens placed in front of an inflector, which is located at the center of the main magnet.

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대형 액상분사식 LPG 엔진의 희박연소특성에 관한 연구 (Lean Burn Characteristics in a Heavy Duty Liquid Phase LPG Injection SI Engine)

  • 오승묵;김창업;이진욱;김창기;강건용;배충식
    • 연구논문집
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    • 통권33호
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    • pp.5-16
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    • 2003
  • Fuel distribution, combustion, and flame propagation characteristics of heavy duty engine with the liquid phase LPG injection(LPLI) were studied in a single cylinder engine. Optically accessible single cylinder engine and laser diagnostics system were built for quantifying fuel concentration by acetone PLIF(planar laser induced fluorescence) measurements. In case of Otto cycle engine with large bore size, the engine knock and thermal stress of exhaust manifold are so critical that lean burn operation is needed to reduce the problems. It is generally known that fuel stratification is one of the key technologies to extend the lean misfire limit. The formation of rich mixture in the spark plug vicinity was achieved by open valve injection. With higher swirl strength(Rs=3.4) and open valve injection, the cloud of fuel followed the flow direction and the radial air/fuel mixing was limited by strong swirl flow. It was expected that axial stratification was maintained with open-valve injection if the radial component of the swirling motion was stronger than the axial components. The axial fuel stratification and concentration were sensitive to fuel injection timing in case of Rs=3.4 while those were relatively independent of the injection timing in case of Rs2.3. Thus, strong swirl flow could promote desirable axial fuel stratification and, in result, may make flame propagation stable in the early stage of combustion.

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SPRAY AND COMBUSTION CHARACTERISTICS OF HYDROCARBON FUEL INJECTED FROM PRESSURE-SWIRL NOZZLES

  • Laryea Gabriel Nii;No Soo-Young
    • 한국분무공학회지
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    • 제9권4호
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    • pp.31-37
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    • 2004
  • This paper presents spray and combustion characteristics of hydrocarbon fuel injected from pressure-swirl nozzles. Three commercial nozzles with orifice diameters of 0.256, 0.308 and 0.333mm and injection pressures ranging from 0.7 to 1.3 MPa were selected f9r the experiments. Spray characteristics such as breakup length. spray angle and drop size (SMD) were analyzed using photo image analyses and Malvern Panicle Size Analyzer. The drop size was measured with and without a blower at the same measuring locations. The flame length and width were measured using photo image analyses. The temperature distribution along the axial distance and the gas emission such as CO, $CO_2\;and\;NO_x$ were studied. The breakup length decreased with an increase in injection pressure for each nozzle but increased with an increase in nozzle orifice diameter. The spray angle increased and SMD decreased with an increase in injection pressure. The flame with an increased linearly with an increase in injection pressure and in nozzle orifice diameter. The flame temperature increased with an increase in injection pressure but decreased along the axial distance. The maximum temperatures occurred closer to the burner exit and flame at axial distance of 242mm from the diffuser tip. The experimental results showed that the level of CO decreased while that of $CO_2\;and\;NO_x$ increased with an increase in injection pressure and nozzle orifice diameter.

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다단 축류압축기의 안정성 개선을 위한 실험적 연구 (Experimental Research of Multi-Stage Axial Compressor Stability Enhancement by Air Injection)

  • 임영천;임형수;송성진;강신형
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2009년도 제33회 추계학술대회논문집
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    • pp.378-381
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    • 2009
  • 압축기에 불안정한 특성인 선회실속(Rotating stall)이 발생하면 압력 및 효율이 저하되고, 기계적인 손상도 야기한다. 이러한 불안정성을 개선하고 안정 운전영역을 넓히기 위해 4단 저속 축류압축기에 공기 분사(Air injection) 방법을 적용하여 안정성 개선 실험을 실시하였다. 동익 팁에 축방향으로 공기를 분사할 수 있도록 하기 위해 코안다 효과를 적용한 노즐을 사용하였고, 8개의 인젝터를 1단 동익 상단에 등간격으로 설치하였다. 축류 압축기 80% speed로 운전하면서 선회실속이 발생하기 전에 공기 분사를 실시하였고, 모드(Mode) 발생 유량의 5.4%에 해당하는 공기를 분사하여 약 4%의 안정성 개선 효과를 얻었다.

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정익 슈라우드 공기분사가 단단 천음속 축류압축기의 공력성능에 미치는 영향 (Effects of Stator Shroud Injection on the Aerodynamic Performance of a Single-Stage Transonic Axial Compressor)

  • 딩꽁쯔엉;마상범;김광용
    • 대한기계학회논문집B
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    • 제41권1호
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    • pp.9-19
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    • 2017
  • 본 연구에서는 단단 천음속 축류압축기 정익부 슈라우드에 공기분사기를 설치하는 방안을 제시하고 이 것이 공력성능에 미치는 영향을 분석하기 위해 매개변수 연구를 수행하였다. 분사기의 곡률, 폭, 정익 앞전으로부터의 거리, 원주방향 각도 및 공기분사 비율을 변수로 선정하였고, 각 변수의 변화에 따른 공력성능 영향을 분석하기 위해 삼차원 레이놀즈평균 나비어-스톡스 방정식을 사용한 공력해석을 수행하였다. 매개변수 연구 결과, 정익 분사가 적용된 단단 축류압축기의 공력성능이 향상되었고, 공력성능이 공기분사 비율에 민감한 영향을 받는 것이 확인되었다. 원주방향 각도의 비율이 10%일 때 전압력비와 단열 효율이 가장 크게 향상되었다.