• Title/Summary/Keyword: Injection-rate

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Effect of Injector Energizing Duration on the Atomization Characteristics of Biodiesel Fuel (인젝터 통전기간이 바이오디젤 연료 미립화에 미치는 영향)

  • Suh, Hyun-Kyu;Park, Su-Han;Lee, Chang-Sik
    • Journal of ILASS-Korea
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    • v.12 no.2
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    • pp.108-114
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    • 2007
  • This study investigates the influence of energizing duration on the fuel atomization characteristics of biodiesel injected through a high pressure common-rail injector. In order to analyze the effect of energizing duration on the fuel injection rate performance, the injection rate of biodiesel fuel is obtained from the pressure variation in the tube filled with fuel in injection measuring system. On the other hand, the atomization characteristics of biodiesel was measured and compared in terms of Sauter mean diameter(SMD), arithmetic mean diameter(AMD), droplet mean velocity, and detected droplets number by applying a phase Doppler particle analyzer(PDPA). It was revealed that the injection mass and maximum injection rate increase with increase of the energizing duration. Moreover, the increase of energizing duration improves the atomization performance of biodiesel fuel because it induces higher droplets momentum and velocity.

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Effects of Injection Conditions on the Weld Line Creation in Injection Molding (사출성형시 성형조건이 웰드라인의 생성에 미치는 영향)

  • Kim, Young-Mo;Park, Yeong-Min;Jang, Min-Kyu;Jeong, Yeong-Deug
    • 한국금형공학회:학술대회논문집
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    • 2008.06a
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    • pp.115-119
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    • 2008
  • Weld line in injection molded part is one of the defects in injection molding process. Weld line deteriorates not only appearance quality but mechanical property. In this study, ABS and PP were used as experimental materials. And weld line length, depth and strength have been examined according to the injection molding conditions. As the results of experimental studies, weld line length increased as flow rate increases for all materials. And the flow rate is most influenced to the creation of weld line length. Also weld line strength increased, as flow rate and melt temperature increase for all materials. The whole experiment results was similar to CAE analysis results.

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Modeling Geologic Storage of Carbon Dioxide: Effects of Low-permeability Layer on Migration of CO2 (이산화탄소 지중저장 모델링: 저투수 이질협재층이 이산화탄소 거동에 미치는 영향)

  • Han, Ahreum;Kim, Taehee;Kwon, Yikyun;Koo, Min-Ho
    • Journal of Soil and Groundwater Environment
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    • v.22 no.3
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    • pp.42-49
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    • 2017
  • TOUGH2 was used to simulate the migration of $CO_2$ injected into a sandy aquifer. A series of numerical simulations was performed to investigate the effects of a low-permeability layer (LPL) embedded in the aquifer on the injection rate and the pressure distribution of $CO_2$. The results show that the size and location of the LPL greatly affected the spread of $CO_2$. The pressure difference between two points in the aquifer, one each below and above the LPL, increased as the size of the LPL increased, showing a critical value at 200 m, above which the size effect was diminished. The location of the LPL with respect to the injection well also affected the migration of $CO_2$. When the injection well was at the center of the LPL, the injection rate of $CO_2$ decreased by 5.0% compared to the case with no LPL. However, when the injection well was at the edge of the LPL, the injection rate was decreased by only 1.6%. The vertical distance between the injection point and the LPL also affected the injection rate. The closer the LPL was to the injection point, the lower the injection rate was, by up to 8.3%. Conclusively, in planning geologic storage of $CO_2$, the optimal location of the injection well should be determined considering the distribution of the LPL in the aquifer.

Lab-Scale Air/Bio-Sparging Study to Remediate Diesel-Contaminated Soil and Groundwater : The Effect of Air Injection Rate and Pattern (디젤오염 토양 및 지하수 복원을 위한 공기주입정화법 실험실 연구 : 공기주입량과 공기주입방식의 영향)

  • Chang, Soon-Woong;Lee, Si-Jin;Cho, Su-Hyung;Yoon, Jun-Ki
    • Journal of Soil and Groundwater Environment
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    • v.11 no.4
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    • pp.10-17
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    • 2006
  • Laboratory-scale two-dimensional aquifer physical model studies were conducted to assess the effect of air injection rate and air injection pattern on the removal of disel contaminated soil and groundwater by air/bio-sparging. The experimental results were represented that the optimal conditions in this experiment were as air injection rate of 1,000 ml/min and pulsed air injection pattern(15 min on/off). The results of the TPH reduction, DO consumption and $CO_2$ production indicate the effective biodegradation evidence of diesel. Based on our results, The minimal $O_2$ supply and pulsed air injection pattern could effectively enhance the diesel removal and the pulsing air injection had effect on oxygenation in this system. Thus, the cost of operating air/bio-sparging system will be reduced if optimal air injection rate and pulsed air injection pattern are applied to remediate contaminants.

Gravity-Injection Core Cooling After a Loss-of-SDC Event n the YGN Units 3 & 4

  • Seul, Kwang-Woo;Bang, Young-Seok;Kim, Hho-Jung
    • Nuclear Engineering and Technology
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    • v.31 no.5
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    • pp.476-485
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    • 1999
  • In order to evaluate the gravity-injection capability to maintain core cooling after a loss-of-shutdown-cooling event during shutdown operation, the plant conditions of the Yong Gwang Units 3&4 were reviewed. The six cases of possible gravity-injection paths from the refueling water tank (RWT) were identified and the thermal-hydraulic analyses were performed using the RELAP5/MOD3.2 code. The core cooling capability was significantly dependent on the gravity-injection path, the RCS opening, and the injection rate. In the cases with the pressurizer manway opening higher than the RWT water level, the coolant was held up in the pressurizer and the system pressure continued increasing after gravity-injection. The gravity injection eventually stopped due to the high system pressure and the core was uncovered. In the cases with the injection path and opening on the same leg side, the core cooling was dependent on whether the water injected from the RWT passed the core region or not. However, in the cases with the injection path and opening on the different leg side, the system was well depressurized after gravity-injection and the core boiling was successfully prevented for a long-term transient. In addition, from the sensitivity study on the gravity-injection flow rate, it was found that about 54 kg/s of injection rate was required to maintain the core cooling and the core cooling could be provided for about 10.6 hours after event with that injection rate from the RWT. Those analysis results would provide useful information to operators coping with the event.

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The decision of forming condition and design of injection mold by considering contraction rate of POM resin (POM 수지의 수축율을 고려한 사출금형설계 및 성형조건 선정)

  • Lee, K.Y.;Kim, H.M.;Park, S.S.;Park, H.Y.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2006.05a
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    • pp.180-183
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    • 2006
  • The contraction rate is a very important element that dominate quality of product in plastic injection molding. To get wanted products, the contraction rate of used resin must be considered necessarily when designing plastic injection molds, and suitable deform conditions must be chosen with this. In this paper, important parts used in LED department were produced by injection mold using POM resin, and dimension error that happened by contraction rate of resin was corrected and reflected in die design and suitable deform conditions were decided.

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Comparison of Spray Characteristics according to Physical Properties of Ethanol/Gasoline Blended Fuel (에탄올/가솔린 혼합연료의 물리적 특성에 따른 분무 특성 비교)

  • Kim, Woong Il;Kim, Youngkun;Lee, Hwang Bok;Lee, Kihyung
    • Journal of ILASS-Korea
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    • v.22 no.3
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    • pp.109-115
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    • 2017
  • The aim of this study is to investigate the effect of physical properties of fuels on spray characteristics in the gasoline direct injection system. Injection rate, spray visualization, and spray pattern experiments were performed to analyze the spray characteristics of ethanol, gasoline, and ethanol/gasoline blends. We measured injection rate of each fuel via the Bosch method. The spray visualization experiment was also carried out at atmospheric pressure using a high-speed camera. Finally, the average of drop surface area per unit volume was measured using the optical patternator. The experimental results from Bosch method showed that peak injection rate increased when the volume fraction of ethanol increased. In addition, higher viscosity of ethanol than that of gasoline leads to longer injection delay. At the initial injection region before reaching 0.8 ms, the spray tip penetration becomes longer as increasing the volume fraction of ethanol, but reversely shorter after 0.8 ms. It was found that ethanol makes spray angle become larger. The surface area per unit volume of the drop was decreased as the distance from the injection tip or the concentration of the gasoline increased.

Analysis of Transient Diesel Spray with Visualization and Injection Rate Measurement (가시화와 분사율 측정을 통한 비정상 디젤분무의 분석)

  • Kang, Jin-Suk;Choi, Wook;Bae, Choong-Sik
    • Transactions of the Korean Society of Automotive Engineers
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    • v.12 no.5
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    • pp.12-18
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    • 2004
  • Transient natures of diesel sprays are often characterized with spray visualization, since it is a non-intrusive and straightforward technique to be applied. However, as injection pressure is increased higher than a thousand bar in a modern direct injection diesel engine, very fine temporal and spatial resolutions in the spray visualization are required while sprays become optically denser. Discussed in this paper are macroscopic and microscopic spray visualization techniques and an example of image processing process for efficient and consistent measurement of spray parameters. The injection rate measurement method based on hydraulic pulse principle was suggested as a way of estimating injection velocity for transient diesel sprays. The spray visualization and injection rate measurement techniques were applied to analyze transient diesel sprays from a common-rail injection system and found to be practically effective.

Research of Shrinkage Phenomenon on Metal Insert Injection Molded Parts (금속인서트 사출성형품의 수축현상에 관한 연구)

  • Jeong, Y.D.;Kim, Y.S.;Kim, I.K.;Jung, H.C.
    • Journal of Power System Engineering
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    • v.2 no.1
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    • pp.80-85
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    • 1998
  • Engineering plastics have been magnified its usability due to its outstanding mechanic al, electrical and chemical properties, for example, in the area of computer, electricity, electronics, automobile, camera industry. In recent, automobile speedometer system is changing from manual operation to motor operation. All plastic gears inserted by metal shaft are used In motor operated speedometer system. Therefore, in this research, experimental investigation of the shrinkage phenomenon was executed according to various inserted depth and injection conditions. In experiments, the inserted depth was controlled as 30% and 90% of the total thickness of the plastic gear. The main parameters of injection process were selected as injection pressure, holding pressure, melt temperature, injection rate. As main results, free shrinkage rate of the test part is increased about 4 times to restricted shrinkage rate and shrinkage phenomenon against all injection conditions have a trivial effect on the test parts as conventional parts.

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Study on Spray Characteristics of Single-Hole GDI Injector according to Nozzle Hole Diameter - (1) Comparison of Injection and Macroscopic Spray Characteristics (노즐 홀 직경에 따른 단공 GDI 인젝터의 분무 특성 연구 - (1) 분사 및 거시적 분무특성 비교)

  • Park, Jeonghyun;Ro, Seungcheon;Chang, Mengzhao;Park, Suhan
    • Journal of ILASS-Korea
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    • v.25 no.4
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    • pp.145-153
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    • 2020
  • The purpose of this study is to compare the injection and spray characteristics of single-hole GDI injectors using injection rate and mie-scattering spray images. Five types of single-hole injectors with different nozzle hole diameters were used, and the spray rate, spray tip penetration, spray area, and spray width were analyzed. As a result, the diameter of the nozzle hole had a direct effect on the injection and spray characteristics. It was confirmed that the larger the diameter of the nozzle hole, the higher the injection quantity, the spray tip penetration, the spray area, and the spray width. In addition, it was confirmed that the near-field spray, which has little influence of ambient air, has a great correlation with the injection rate.