서지주요정보
2유체 분사장치의 분무 및 연소 특성에 관한 연구 = A study on the spray and combustion characteristics of a twin-fluid injector
서명 / 저자 2유체 분사장치의 분무 및 연소 특성에 관한 연구 = A study on the spray and combustion characteristics of a twin-fluid injector / 김기성.
저자명 김기성 ; Kim, Ki-Seong
발행사항 [대전 : 한국과학기술원, 1994].
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소장정보

등록번호

8004207

소장위치/청구기호

학술문화관(문화관) 보존서고

DME 94013

휴대폰 전송

도서상태

이용가능

대출가능

반납예정일

리뷰정보

초록정보

Studies were performed on the spray and combustion characteristics of an air-assisted fuel injector which was designed for application to 2-stroke direct injection engine. Firstly, experimental studies were performed to investigate the operating and spray characteristics of this injector. Schlieren photography was employed to observe the shape and penetration of the spray. Effects from the nozzle deflector and injected air-fuel ratio(ALR) were studied. In addition, we investigated whether there were large droplets resulting from fuel dripping at the beginning and end of injection. Except for an small ALR range, very few big droplets over $\sim 100 \mu{m}$ in diameter were produced. Also, fuel was ejected from the poppet exit not in the form of ligaments or sheets but rather in the form of finely atomized droplets. The sizes and velocities of droplets were measured by a TV imaging system. This imaging system has a capability to measure very small drops(calibrated down to 3.9$\mu$m in diameter) by developing a reliable calibration procedure and an image processing algorithm for automatic sizing and counting of the particle images. For an ALR below 1, the mean drop size increased rapidly with decreasing ALR. However, when it was greater than 2, the reduction in mean drop size was less noticeable with increasing ALR. SMD turned out to be under 12$\mu$m for an ALR greater than 1. In addition, the size distribution of droplets showed almost linear characteristics when displayed in Square-Root/Normal Probability plots. The MMD/SMD ratio was shown to scatter between 1.1 and 1.2. Velocities and sizes of droplets were simultaneously measured and compared with the criteria of the bag breakup model and boundary layer stripping model. Since droplet velocities were too low relative to droplet sizes, it turned out that there was almost no possibility for secondary breakup. Secondly, visual study on the combustion of the spray from the air-assisted fuel injector was performed using a single-shot optical engine driven by a rapid compression and expansion machine(RCEM). In these study, the effects of ignition method, intake swirl ratio, spark timing, injection timing, and injected fuel and air mass were investigated. It was found out that three strike ignition method exhibited more stable ignitability compared with single strike one. The distortion of the spray toward the swirl direction was severe and the higher the swirl ratio, the faster the buming rate. The interval between the spark timing and injection timing determined the dispersion of the droplet cloud and so had a effect on the combustion. Therefore optimum timings were necessary for the best performance. The injected fuel and air mass also had a effect on the droplet dispersion by affecting the mean drop size of the spray. Lastly, computation of the spray from the air-assisted fuel injector was performed using KIVA-II code. In this study, the effects of the conditions in the poppet exit were investigated.

서지기타정보

서지기타정보
청구기호 {DME 94013
형태사항 xiv, 146 p. : 삽도 ; 26 cm
언어 한국어
일반주기 저자명의 영문표기 : Ki-Seong Kim
지도교수의 한글표기 : 김성수
지도교수의 영문표기 : Sung-Soo Kim
학위논문 학위논문(박사) - 한국과학기술원 : 기계공학과,
서지주기 참고문헌 : p. 142-146
주제 Nozzles.
Schlieren photography.
Combustion.
Automobiles --Spray control.
연소실. --과학기술용어시소러스
연료 분사. --과학기술용어시소러스
이젝터. --과학기술용어시소러스
화상 처리. --과학기술용어시소러스
노즐. --과학기술용어시소러스
Injectors.
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