• Title, Summary, Keyword: injector

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An Experimental Study on the Waveform Analysis According to Troubles of Piezo Injector of CRDI Diesel Engine (CRDI 디젤엔진의 피에조 인젝터 불량에 따른 파형 분석에 관한 실험적 연구)

  • Yoo, Jong-Sik;Kim, Chul-Soo
    • Journal of the Korean Society of Mechanical Technology
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    • v.20 no.6
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    • pp.783-789
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    • 2018
  • This paper investigates the relationship of voltage and current waveform between normal piezo injector and deterioration abnormal piezo injector. The experimental methods using Pico oscilloscope and GDS scan tool are employed to measure current and voltage waveform and fuel pressure of piezo injector. The experiment is carried out during no-load condition. A summary of the important results are as follows. 1) In case of normal injector, the fluctuation of duration time of piezo injector was linearly and regularly decreased with increasing engine speed, but the that of deterioration piezo injector was irregularly decreased with increasing engine speed. 2) In main injection, the peak value of the current waveform of abnormal injector was larger than that of normal injector, the duration time of deteriorated abnormal injector was less than that of normal injector at 800rpm and 1500rpm, but the duration time of deteriorated abnormal injector was larger than that of normal injector at 2000rpm and 3000rpm. This irregularity appears to be caused by the deterioration of the injector.

Experimental Study of the Role of Gas-Liquid Scheme Injector as an Acoustic Resonator in a Combustion Chamber

  • Kim Hak-Soon;Sohn Chae-Hoon
    • Journal of Mechanical Science and Technology
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    • v.20 no.6
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    • pp.896-904
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    • 2006
  • In a liquid rocket engine, the role of gas-liquid scheme injector as an acoustic resonator or absorber is studied experimentally for combustion stability by adopting linear acoustic test. The acoustic-pressure signals or responses from the chamber are monitored by acoustic amplitude. Acoustic behavior in a rocket combustor with a single injector is investigated and the acoustic-damping effect of the injector is evaluated for cold condition by the quantitative parameter of damping factor as a function of injector length. From the experimental data, it is found that the injector can play a significant role in acoustic damping when it is tuned finely. The optimum tuning-length of the injector to maximize the damping capacity is near half of a full wavelength of the first longitudinal overtone mode traveling in the injector with the acoustic frequency intended for damping in the chamber. When the injector has large diameter, the phenomenon of the mode split is observed near the optimum injector length and thereby, the acoustic-damping effect of the tuned injectors can be degraded.

High Speed Operation of Fuel Injectors with Over Current Protection (과전류 제한 기능을 갖는 연료 분사장치의 고속 구동 방법)

  • Yang, Hyong-Yeol;Suh, Eui-Suk
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.11
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    • pp.2043-2048
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    • 2011
  • High speed drive method for a fuel injector cleaner with current control is presented in this paper. The fuel injector cleaner is used for cleaning the fuel injectors in vehicles when it is clogged with deposit and rust. The fuel injector cleaner cleans the fuel injector by turning on and off the fuel injector rapidly. When the fuel injectors are cleaned, the switching speed is very important. However, when the fuel injector is turned off, the residual current in the fuel injector coil slows down the return action of the plunger in the fuel injector deteriorating performance and speed of the fuel injector cleaner. In this paper, fast turn off operation method of fuel injectors is developed for more effective cleaning. The simulation and experiment results show the validity of the proposed method.

Performance Prediction of solenoid Actuated Hydrogen Injector (솔레노이드 구동 수소인젝터의 성능예측)

  • 이형승;이용규;김한조;김응서
    • Transactions of the Korean Society of Automotive Engineers
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    • v.5 no.1
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    • pp.174-185
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    • 1997
  • The performance of the solenoid actuated hydrogen injector and the capacitive peak-hold type driving circuit was predicted through the modeling of the injector and the driving circuit the modeling was composed of the driving circuit, the solenoid, the moving parts of the injector, and the hydrogen injection system. The performance of the injector through the modeling was compared with the results of the solenoid and injector rig tests, and those were consistent with each other. Through the prediction of the injector performance, the effects of the components such as electrical resistor, capacitor, and injector spring are easily known to the injector performance required.

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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
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    • v.14 no.4
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    • pp.164-173
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    • 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.

Analytical Study on Unsteady Flow Characteristics of Urea-SCR Single Hole Injector depend on Nozzle Shape Change (Urea-SCR 단홀 Injector 노즐형상 변화에 따른 비정상유동특성의 해석적 연구)

  • Hwang, Jun Hwan;Park, Sung-Young
    • Journal of ILASS-Korea
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    • v.24 no.3
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    • pp.105-113
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    • 2019
  • In this paper, a study of Urea-SCR System for Dosing Injector for responding to enhanced environmental regulations has been conducted. There is a limit to the experimental approach due to the structural characteristics of the injector. In order to overcome this problem, The analysis was performed assuming unsteady turbulent flow through computational fluid analysis and the internal flow characteristics of the injector were analyzed. By changing the nozzle shape of the injector, the performance factors of the swirl injector by shape were selected and compared. The design parameters were modified by changing the diameter of the nozzle at a constant ratio compared to the base model. Swirl coefficient, outlet mass flow, and sac volume were selected as performance parameters of the injector. The Conv. model to which the taper was applied showed the dominance in mass flow rate, discharge coefficient and swirl because of the smooth fluid flow by shape. Swirl coefficient, outlet mass flow, and sac volume were selected as performance parameters of the injector. As a result of the comparison coefficient derivation with those performance parameters for comparing the performance of the model-specific injector, the Conv-140 model with the nozzle diameter expanded by 140% showed the best value of the comparison coefficient.

Effect of Gas-Liquid Scheme Injector on Acoustic Damping in Liquid Rocket Engine (액체 로켓엔진 분사기의 음향감쇠 효과에 관한 수치적 연구)

  • Park, I-Sun;Sohn, Chae-Hoon
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.33 no.5
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    • pp.79-86
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    • 2005
  • The role of the injector as an acoustic resonator is studied for the high performance rocket engine adopting the gas-liquid scheme injector. Acoustic behavior in the combustor with single injector is investigated numerically adopting linear acoustic analysis for cold condition. Acoustic-damping effect of the injector is evaluated by damping factor as a function of the injector length. From the numerical results, it is found that the injector can play a significant role in acoustic damping and the optimum length of the injector corresponds to half of a full wavelength of the longitudinal mode with the acoustic frequency to be damped in the chamber. In baffled chamber, the optimum lengths of the injector are calculated as a function of baffle length for both cold and hot conditions.

Effect of Injector-driven Type on Spray Behavior and Fuel Atomization Characteristics (인젝터 구동 방식에 따른 분무 거동 및 분무 미립화 특성)

  • Park, Ji-Hong;Suh, Hyun-Kyu;Park, Sung-Wook;Kim, Jae-Wook;Lee, Chang-Sik
    • Transactions of the Korean Society of Automotive Engineers
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    • v.14 no.1
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    • pp.17-24
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    • 2006
  • This study was performed to figure out spray behavior and fuel atomization characteristics of a piezo-driven injector and a solenoid-driven injector in the common-rail injection system under the same design parameters and test conditions. The process of spray injection was visualized by using the spray visualization system composed of a Nd:YAG laser and an ICCD camera. The atomization characteristics were investigated in terms of axial mean velocity, Sauter mean diameter(SMD) and droplet distributions obtained from a phase Doppler particle analyzer system. Compared with solenoid-driven injector, the piezo-driven injector has short injection delay and reaches quickly to the maximum injection value. Spray tip penetration shows some difference, however, spray angle of piezo-driven injector is wider than that of solenoid-driven injector. Sauter mean diameter of piezo-driven type injector is smaller than that of solenoid-driven type.

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
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    • pp.239-243
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    • 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.

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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
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    • pp.239-243
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    • 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.

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