서지주요정보
가솔린 직접분사식 엔진용 고압선회식 분사기 노즐의 분무특성 파악 및 성능최적화 연구 = Spray characterization and performance optiminization of high pressure swirl injector nozzles for gasoline direct injection engines
서명 / 저자 가솔린 직접분사식 엔진용 고압선회식 분사기 노즐의 분무특성 파악 및 성능최적화 연구 = Spray characterization and performance optiminization of high pressure swirl injector nozzles for gasoline direct injection engines / 장창수.
저자명 장창수 ; Jang, Chang-Soo
발행사항 [대전 : 한국과학기술원, 2000].
Online Access 원문보기 원문인쇄

소장정보

등록번호

8011442

소장위치/청구기호

학술문화관(문화관) 보존서고

DME 00048

SMS전송

도서상태

이용가능

대출가능

반납예정일

초록정보

Interest on the fuel injection technology is increasing recently as its importance in the development of gasoline direct injection engines has become more evident. The main focus of this study is on the spray and flow characteristics of high pressure swirl injectors (HPSI) applicable to these engines. Prototype injectors were designed and fabricated. Comparison of the injector performance with an air-assisted fuel injector (AAFI) was also attempted. In order to achieve these goals, the computational fluid dynamics as well as the experimental measurement was utilized. In Chapter 3, basic characteristics of HPSI nozzles are described. Prototype swirl-generating nozzle was fabricated by modifying an MPI injector nozzle. Experimental parameters included injection pressure, injection duration and ambient pressure. Spray tip penetration and atomization performance were also examined as a function of these parameters. The D_{32} of the swirl nozzle ranged from 20μm to 28μm at an injection pressure of 5MPa, ,which was about 30% smaller than that of the base MPI nozzles. The atomization performance was enhanced with lower ambient pressure and higher injection pressure. Drop size distribution was found to fit to the Rosin-Rammler distribution and to be less dispersed than that of the air-assisted fuel injector and less uniform than those of the diesel injector. In Chapter 4, CFD evaluation of the internal flow of HPSI nozzles was discussed as a preliminary optimization process of the nozzle design. Measurements of the static flow rate were compared with computations, and the agreements were satisfactory in values and tendencies with respect to the needle lift. Initial cone angle was calculated, and compared with measurements by the direct photographic imaging method. It could be predicted satisfactorily by introducing an adequate correction factor. Considering these cross-checking for a validation of the computational model, parametric study was carried out to predict the flow rate and the initial cone angle with respect to the selected design parameters. The most significant parameter on both the static flow rate and the initial cone angle was found to be the orifice diameter. Effects of other parameters were also examined and discussed. Transient flow inside the nozzle was also simulated with respect to the needle motion using the moving-grid utility of the CFD code. Dynamic flow rate was obtained and found to be rather precise compared with that by measurement. The influence of upper needle-seat angle and needle opening duration on initial transient flow was also surveyed. In Chapter 5, performance and characteristics of the AAFI and the HPSI were compared in terms of flow rate, spray pattern, penetration, atomization quality and drop size distribution. ’The characterization processes of both injector sprays were arranged in parallel and were intended to survey nozzle performance. In order to define the spray pattern, a newly defined spray shape factor was introduced. Equations for D_32 prediction obtained in the previous studies were utilized to survey the variation of mean drop diameter of both injectors. Main purpose of the present study is to help the design optimization of combustion chambers and injection nozzles for real engine application. Using characterization data of these sprays, operating factors such as injection timing, common rail pressure, and so on, can be evaluated and adjusted to obtain an optimum combustion quality. Also, analysis of internal flow can make it faster and easier to optimize the nozzle design, and eventually, the spray characteristics.

서지기타정보

서지기타정보
청구기호 {DME 00048
형태사항 xx, 180 p. : 삽도 ; 26 cm
언어 한국어
일반주기 부록 : Ⅰ, 미립화 성능 단운 모델링. - Ⅱ, 노졸 내부유동 계산의 해석. - Ⅲ, 분사기 설계에 대한 고찰
저자명의 영문표기 : Chang-Soo Jang
지도교수의 한글표기 : 최상민
지도교수의 영문표기 : Sang-Min Choi
수록잡지명 : "Characterization of prototype high pressure swirl injector nozzles - part I & part II". Atomization and sprays, v.10 no.2, pp.159-197(2000)
수록잡지명 : "An experimental and analytical study of the spray characteristics of an intermittent air-assisted fuel injector". Atomization and sprays, v.10 no.2, pp.198-216(2000)
학위논문 학위논문(박사) - 한국과학기술원 : 기계공학전공,
서지주기 참고문헌 : p. 135-146
QR CODE qr code