• Title/Summary/Keyword: Injection Rate Profile

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Simulation on the Characteristics of PLN Diesel Injection System by Cam Profile (연료캠 형상에 따른 PLN 디젤 분사계의 분사특성에 관한 시뮬레이션)

  • Lee, J.H.;Wang, W.K.;Ahn, S.K.
    • Journal of Power System Engineering
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    • v.1 no.1
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    • pp.42-51
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    • 1997
  • In this study, in order to investigate the influence of cam profile on the injection rate, the characteristics of injection in PLN (pump - line - nozzle) diesel injection system were simulated. Six types of the profile of fuel cam were used for simulation. The maximum injection pressure and maximum injection rate of initial and end phase were analyzed to demonstrate the characteristics of injection. The mathematical model of the injection system and the computation results were verified by experimental results. Simulation results showed that the maximum injection pressure, maximum injection rate, injection quantity and pressure drop in the end phase were proportional to the velocity of fuel cam during the effective stroke.

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Diesel Combustion Noise Reduction based on the Numerical Simulation (디젤 엔진소음 II)

  • 강종민;안기환;조우흠;권몽주
    • Journal of KSNVE
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    • v.7 no.6
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    • pp.909-918
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    • 1997
  • Combustion oriented noise is a part of engine noise, which is mainly determined by the in-cylinder pressure profile and the structure attenuation of an engine. A numerical model for predicting the in-cylinder pressure profile and the resultant combustion noise developed by the use of a commercial code. The model is experimentally validated and updated based on the performance as well as the noise by considering the fuel injection timing, the fuel injection rate, Cetane number, intake temperature, and compression ratio. For providing a design guide of a fuel injector for a low combustion noise engine model, the optimal parameters of injection pressure profile, injection rate profile, and injection timing are determined, which gives the 5 dBA noise reduction.

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1-D Model to Estimate Injection Rate for Diesel Injector using AMESim (디젤 인젝터 분사율 예측을 위한 AMESim 기반 1-D 모델 구축)

  • Lee, Jinwoo;Kim, Jaeheun;Kim, Kihyun;Moon, Seoksu;Kang, Jinsuk;Han, Sangwook
    • Journal of ILASS-Korea
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    • v.25 no.1
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    • pp.8-14
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    • 2020
  • Recently, 1-D model-based engine development using virtual engine system is getting more attention than experimental-based engine development due to the advantages in time and cost. Injection rate profile is the one of the main parameters that determine the start and end of combustion. Therefore, it is essential to set up a sophisticated model to accurately predict the injection rate as starting point of virtual engine system. In this research, procedure of 1-D model setup based on AMESim is introduced to predict the dynamic behavior and injection rate of diesel injector. As a first step, detailed 3D cross-sectional drawing of the injector was achieved, which can be done with help of precision measurement system. Then an approximate AMESim model was provided based on the 3D drawing, which is composed of three part such as solenoid part, control chamber part and needle and nozzle orifice part. However, validation results in terms of total injection quantity showed some errors over the acceptable level. Therefore, experimental work including needle movement visualization, solenoid part analysis and flow characteristics of injector part was performed together to provide more accuracy of 1-D model. Finally, 1-D model with the accuracy of less than 10% of error compared with experimental result in terms of injection quantity and injection rate shape under normal temperature and single injection condition was established. Further work considering fuel temperature and multiple injection will be performed.

Etching Method of Thin Film on the Backside of Wafer Using Single Wafer Processing Tool (매엽식 방법을 이용한 웨이퍼 후면의 박막 식각)

  • Ahn, Young-Ki;Kim, Hyun-Jong;Koo, Kyo-Woog;Cho, Jung-Keun
    • Journal of the Semiconductor & Display Technology
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    • v.5 no.2 s.15
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    • pp.47-49
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    • 2006
  • Various methods of making thin film is being used in semiconductor manufacturing process. The most common method in this field includes CVD(Chemical Vapor Deposition) and PVD(Physical Vapor Deposition). Thin film is deposited on both the backside and the frontside of wafers. The thin film deposited on the backside has poor thickness profile, and can contaminate wafers in the following processes. If wafers with the thin film remaining on the backside are immersed in batch type process tank, the thin film fall apart from the backside and contaminate the nearest wafer. Thus, it is necessary to etch the backside of the wafer selectively without etching the frontside, and chemical injection nozzle positioned under the wafer can perform the backside etching. In this study, the backside chemical injection nozzle with optimized chemical injection profile is built for single wafer tool. The evaluation of this nozzle, performed on $Si_3N_4$ layer deposited on the backside of the wafer, shows the etching rate uniformity of less than 5% at the etching rate of more than $1000{\AA}$.

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Study of transcription ability of optic polymer and Micro-grooving machining of ultra-precision injection molding moulds (초정밀 사출성형 금형의 마이크로 홈가공과 전사성)

  • Kwak T.S.;Ohmori H.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.623-624
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    • 2005
  • Micro injection molding is a branch of micro system technology and has been under development for the mass manufacture of micro parts. Enhanced technological products like micro optical devices are entering the market. This paper presents fundamental research on the injection molding technique in micro fabrication. In order to successful manufacturing of micro plastic parts, it is necessary to research for development of micro-injection machine, machining of micro mold, decision of optimum injection conditions and the research for polymer material. Therefore in this study, in order to machining of micro mold, a mold core with microscopic V-shaped groove was tooled by ultra-precise tooling machine. The transcription experiments with a polymer, PMMA resin on the surface of core with Ni plating were carried out and surface profile of injected parts was measured with AFM.

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Effects of CMP Retaining Ring Material on the Performance of Wafer Polishing (CMP용 리테이닝 링의 재질이 웨이퍼의 연마성능에 미치는 영향)

  • Park, Ki-Won;Kim, Eun-young;Park, Dong-Sam
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.19 no.3
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    • pp.22-28
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    • 2020
  • This paper investigates the effects of retaining ring materials, particularly PPS and PEEK, used in the CMP process, on wafer polishing and ring wear. CMP can be performed using bonded type retaining rings made with PPS or injection molding type retaining rings made with PEEK. In this study, after polishing a wafer with a PPS retaining ring, the average profile height of the wafer was 0.098 ㎛ less than that of the wafer polished with a PEEK retaining ring, implying that PPS retaining rings achieve a higher polishing rate. In addition, the center area of the wafer profile had less deviation and improved flatness after polishing with the PPS ring. These results indicate that a higher polishing rate and smaller profile height deviation can be achieved using retaining rings made with PPS compared to retaining rings made with PEEK. Therefore, with semiconductor circuit patterns becoming finer and wafer sizes becoming larger, the use of PPS in CMP retaining rings can obtain more stable wafer polishing results compared to that of PEEK.

Once-weekly Subcutaneous Administration of Bortezomib in Patients with Multiple Myeloma

  • Wang, Liang;Wang, Ke-Feng;Chang, Bo-Yang;Chen, Xiao-Qin;Xia, Zhong-Jun
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.5
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    • pp.2093-2098
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    • 2015
  • In patients with multiple myeloma (MM), once-weekly intravenous injection or twice-weekly subcutaneous injection (SC) of bortezomib has been proven to offer non-inferior efficacy to standard twice-weekly intravenous administration, with an improved safety profile. However, whether once-weekly SC bortezomib can further reduce the incidence rate of peripheral neuropathy (PN) and not compromise the efficacy remains to be investigated. 25 patients of MM treated with once-weekly SC bortezomib were reviewed in this study. The median treatment cycles were 4 (range, 2-9 cycles). Complete response (CR) rate was 52%, ${\geq}$very good partial response (VGPR) rate was 72%, and ${\geq}$partial response (PR) rate was 84%. 1-year and 2-year PFS rate was 63.0% and 34.3%, respectively, and 2-year OS rate was 100%. Any grade of PN was reported in 9 patients (36.0%), with 7 patients (28.0%) had grade 1 PN, and 2 patients (8.0%) had grade 2 PN. No patients reported grade 3/4 PN in this cohort. In conclusion, once-weekly subcutaneous administration of bortezomib offers excellent efficacy with a further improved safety profile, especially with regard to PN. It needs to be validated in future prospective randomized trials.

A Study on the Particle Size and Velocity Profile on a Gasoline Port Injector Using a Phase Doppler Particle Analyzers (PDPA) (위상 도플러 입자 분석기(PDPA)를 이용한 가솔린 포트 인젝터의 입자 크기 및 속도 프로파일에 관한 연구)

  • KIM, HYOJIN;JO, HYUN;TONGCHAI, SAKDA;LIM, OCKTACKE
    • Journal of Hydrogen and New Energy
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    • v.28 no.3
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    • pp.300-307
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    • 2017
  • This study is to investigate particle size and velocity profile of gasoline port injector using Phase Doppler Particle Analyzer (PDPA). In this experiment, a GV 250 Delphi port injector used for motorcycles was used for liquid injection. The injector consists of four holes and has a static flow rate of 2.13 g/s. The fuel used in the injection was N-heptane, which is similar to gasoline, as an alternative fuel. The test fuel was injected at an atmospheric temperature of $20^{\circ}C$ and an open atmosphere of 1 atm. The injection time was 10 ms and the injection pressure was 3.5 bar in PDPA experiment. The experimental target position was fiexd at 30, 50 and 75 mm from the nozzle tip and data were collected for a total of 10,000 samples. The experimental results show that the length diameter (D10), the Sauter mean diameter ($D_{32}$), and the mean droplet velocity (MDV) are $45-54{\mu}m$, $99-115{\mu}m$ and 15-21 m/s, respectively.

Improment of Diesel Combustion using multiple injection under Cold Start Condition (냉시동 조건에서 디젤 연소 특성 및 연소 개선에 대한 연구)

  • Lee, Haeng-Soo;Lee, Jin-Woo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.4
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    • pp.711-717
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    • 2017
  • Startability and harmful emissions are the main issues in diesel engine development under cold conditions. The characteristics of combustion with multiple injection were investigated under cold start conditions. For quantitative analysis, the in-chamber pressure profile was measured and combustion visualization using direct imaging was accomplished. With multiple injection, the peak in-chamber pressure and heat release rate were increased compared to single injection. In addition, the period of flame luminosity detection was shortened using multiple injection. Combustion by main injection was improved with an increase in heat released by pilot combustion when the pilot injection quantity was increased. Finally, an increase in injection pressure also showed the possibility of combustion improvement. On the other hand, an increase of in the pilot injection quantity and injection pressure can cause an increase in harmful emissions, such as HC and CO due to wall wetting. Therefore, more sensitive calibration will be needed when applying a multiple injection strategy under cold start conditions.

Optimization of Processing Conditions in Injection Molding Using Genetic Algorithm (유전알고리듬을 이용한 사출성형 공정조건 최적화)

  • Choe, Won-Jun;Sin, Hyo-Cheol;Gwak, Sin-Ung
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.10 s.181
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    • pp.2543-2551
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    • 2000
  • Precision injection molding is an important technology for improving productivity and lowering costs in the fields of medical components, lenses and electrical connectors. The quality of injection molded parts is affected by various processing conditions such as filling time and packing pressure profile. It is difficult to consider all the variables at the same time for prediction of the quality. In this study, the genetic algorithm was used to obtain the optimal processing conditions for minimizing the volumetric shrinkage of molded parts. For a higher convergence rate, the method of design of experiments was used to analyze the relationship between processing conditions and volumetric shrinkage of molded parts, which served as analysis tool for the capability of searching optimal processing conditions but also greatly reduces the calculation time by utilizing the information of searching area. As a practical example, compact disks that require micron-level precision were chosen for the study.