• Title/Summary/Keyword: Injector dynamics

Search Result 42, Processing Time 0.022 seconds

A STUDY OF FLOW CHARACTERISTICS AND DESIGN VARIABLES IN AN LPG INJECTOR (LPG Injector 컷솔 유동 특성 및 설계 변수 연구)

  • Lee, Joon-Sik;Lim, Seol;Kim, Sang-Dug;Song, Dong-Joo
    • 한국전산유체공학회:학술대회논문집
    • /
    • 2008.03a
    • /
    • pp.239-243
    • /
    • 2008
  • Fluid flow in LPG injector is delayed momently around nozzle and leaked accidentally, then engine operation becomes unstable. When attached cutsole injector that we can prevent fuel from leaking. Attaching additional devices cause loss of power and pressure. In this study, We has analyzed the performance of the LPG injector nozzle by changing cutsole geometry numerously by using Computational Fluid Dynamics.

  • PDF

A STUDY OF FLOW CHARACTERISTICS AND DESIGN VARIABLES IN AN LPG INJECTOR (LPG Injector 컷솔 유동 특성 및 설계 변수 연구)

  • Lee, Joon-Sik;Lim, Seol;Kim, Sang-Dug;Song, Dong-Joo
    • 한국전산유체공학회:학술대회논문집
    • /
    • 2008.10a
    • /
    • pp.239-243
    • /
    • 2008
  • Fluid flow in LPG injector is delayed momently around nozzle and leaked accidentally, then engine operation becomes unstable. When attached cutsole injector that we can prevent fuel from leaking. Attaching additional devices cause loss of power and pressure. In this study, We has analyzed the performance of the LPG injector nozzle by changing cutsole geometry numerously by using Computational Fluid Dynamics.

  • PDF

Study on Phase-Amplitude Characteristics in a Simplex Swirl Injector with Low Frequency Range (저주파 압력섭동 범위 내에서의 단일 스월 인젝터의 진폭-위상 특성 연구)

  • Khil, Tae-Ock;Chung, Yun-Jae;Yoon, Young-Bin
    • Journal of the Korean Society of Propulsion Engineers
    • /
    • v.14 no.2
    • /
    • pp.19-28
    • /
    • 2010
  • Generally, combustion instability is generated by the mutual coupling between the heat release and the acoustic pressure in the combustor. On the occasion, the acoustic pressure generates the oscillation of the mass flow rate of propellant injected from injector, and this oscillation again affects combustion in the combustor. So, the dynamic characteristics of the injector have been studied to control combustion instability using injector itself in Russia from 1970's. In order to study injector dynamics, a mechanical pulsator for forced pressure pulsation is produced and the method to quantify the mass flow rate of the propellant that is oscillating at the exit of the injector is developed. With the pulsator and the method, pulsating values of the mass flow rate, pressure, liquid film thickness, and axial velocity generated at the exit of the simplex swirl injector are measured in real time. And phase-amplitude characteristics of each parameter are analyzed using these pulsating values acquired at the exit of the simplex swirl injector.

Analysis of Hydraulic Characteristics of High Pressure Injector with Piezo Actuator (피에조 액츄에이터 적용 고압 인젝터의 유압 동특성 해석)

  • Lee, Jin-Wook;Min, Kyoung-Doug
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.14 no.4
    • /
    • pp.164-173
    • /
    • 2006
  • In the electro-hydraulic injector for the common rail Diesel fuel injection system, the injection nozzle is being opened and closed by movement of a injector's needle which is balanced by pressure at the nozzle seat and at the needle control chamber, at the opposite end of the needle. In this study, the piezo actuator was considered as a prime movers in high pressure Diesel injector. Namely a piezo-driven Diesel injector, as a new method driven by piezoelectric energy, has been applied with a purpose to develop the analysis model of the piezo actuator to predict the dynamics characteristics of the hydraulic component(injector) by using the AMESim code. Aimed at simulating the hydraulic behavior of the piezo-driven injector, the circuit model has been developed and verified by comparison with the experimental results. As this research results, we found that the input voltage exerted on piezo stack is the dominant factor which affects on the initial needle behavior of piezo-driven injector than the hydraulic force generated by the constant injection pressure. Also we know the piezo-driven injector has more degrees of freedom in controlling the injection rate with the high pressure than a solenoid-driven injector.

Parameter Estimation and Modeling of HSDI Common-Rail Injector Using Feedforward Neural Network (앞먹임 신경회로망을 이용한 HSDI Common-Rail 인젝터의 파라미터 추정 및 모델링)

  • Yoon, Ma-Ru;Sunwoo, Myoung-Ho;Lee, Kang-Yoon;Lee, Seung-Jong
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.28 no.8 s.227
    • /
    • pp.984-988
    • /
    • 2004
  • This study presents the process of the solenoid parameter estimation of an common-rail injector fer HSDI(High Speed Direct Injection) diesel engines. The EMF(Electromotive Force) and solenoid inductance are the major parameters for presenting the injector dynamics, and also these parameters are estimated by using a multi-layer feedforward artificial neural networks(ANN). The performances of parameter estimators are verified by the simulation with injector model. The feasibility of this methodology is closely examined through the simulation in the various operating points of injector. The simulation results have revealed that estimated parameters show favorable agreements with the common-rail injector model.

Study on Combustion Characteristics of Unielement Thrust Chambers with Various Injectors

  • Seonghyeon Seo;Lee, Kwang-Jin;Han, Yeoung-Min;Kim, Seung-Han;Kim, Jong-Gyu;Moon, Il-Yoon;Seol, Woo-Seok
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • 2004.03a
    • /
    • pp.125-130
    • /
    • 2004
  • Experimental study on combustion characteristics of double swirl coaxial injectors has been conducted for the assessment of critical injector design parameters. A reusable, unielement thrust chamber has been fabricated with a water-cooled copper nozzle. Two principle design parameters, a swirl angle and a recess length, have been investigated through hot firing tests for the understanding of their effects on high pressure combustion. Clearly, both parameters considerably affect the combustion efficiency, dynamics and hydraulic characteristics of an injector. Internal mixing of propellants in a recess region increases combustion efficiency along with the increase of a pressure drop required for flowing the same amount of mass flow rates. It is concluded that pressure buildup due to flame can be released by the increase of LOx flow axial momentum or the reduction of a recess length. Dynamic pressure measurements of the thrust chamber show varied dynamic behaviors depending on injector configurations.

  • PDF

Flow Control of a Solenoid Gas Injector and Its Application on a Natural Gas Engine (솔레노이드 가스 인젝터의 유량제어와 천연가스엔진에서의 응용)

  • Sim, Han-Sub
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.8 no.2
    • /
    • pp.83-89
    • /
    • 2009
  • An air-fuel ratio control is essential in reducing hazardous exhaust emissions from a compressed natural gas(CNG) engine, and can be accomplished by accurate control of gas injection flow. In this study, theoretical research was conducted on injection characteristics of a solenoid gas injector, and injection experiments for calibration and analysis were performed. Various factors for gas injection flow such as injection pressure, gas temperature, and supply voltage are studied. A dynamic flow equation of the natural gas was proposed on the basis of flow dynamics theories and results of the injection experiment. The verification of the dynamic flow equation of the solenoid injector was carried out with a large CNG-engine applied to an urban bus. Air-fuel ratio control experiments were conducted in both steady and transient state. Results of injection experiments for the solenoid injector and the CNG-engine was proved the control method proposed herein to be effective.

  • PDF

A numerical study on the characteristics of internal flows in a gasoline direct swirl injector (직접분사식 가솔린 선회 분사기에서의 내부 유동특성에 관한 수치 해석)

  • Bae, S.H.;Moon, S.Y.;Lee, C.W.
    • Journal of ILASS-Korea
    • /
    • v.6 no.2
    • /
    • pp.9-15
    • /
    • 2001
  • The internal flow characteristics of a gasoline direct injector have been studied to improve fuel economy and reduce exhaust emissions. Computational Fluid Dynamics (CFD) is used to examine the internal flow of the GDI with the purpose of designing the optimum geometry of the injector. This study tests orifice length, cone angle, swirl angle, orifice diameter and needle lift. The results show that optimum sizes of the orifice length, cone angle, swirl angle, orifice diameter and needle lift are 0.8mm, $140^{\circ},\;120^{\circ},\;80mm\;and\;70{\mu}m$, respectively. The size of the lift does not affect the formation of the air core signficantly near the tip of the needle compared to the ball-type needle. The vena contracta phenomenon near the orifice inlet can be released by smoothing the edge.

  • PDF

Study on Spray Phenomena and Optimal Design of Injector for Improving Small Thruster Performance (소형 추력기의 성능 개선을 위한 액체 추진제 주입기 최적 설계 및 추진제 거동 연구)

  • Kim, Ki-Ro;Kim, Su-Kyum;Byun, Do-Young;Lee, Se-Min;Jung, Kang-Su;Park, Soo-Hyung;Kim, Sung-Kyun;Yu, Myoung-Jong
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.39 no.4
    • /
    • pp.341-347
    • /
    • 2011
  • This work studies the performance of an injector for a monopropellant thruster, comparing a conventional and new injector types. The conventional injector consists of 8 nozzles on a convex surface allowing the jet to be diverged. The new injector, we suggested, is an impinging type with nozzle holes on a concave surface. The fuel streams through the nozzle holes are collide at a point on an axial direction, which allow to atomize the liquid streams and to spray more uniformly along circular direction. The performance of the injectors is investigated by using computational fluid dynamics, particle image velocimetry and high speed camera visualization.

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
    • /
    • v.20 no.3
    • /
    • pp.168-174
    • /
    • 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.