서지주요정보
P-L-N 디젤 분사계의 개변압에 따른 연료 미립화 특성 변화 = Variation of fuel atomization characteristics with opening pressure of P-L-N diesel injection system
서명 / 저자 P-L-N 디젤 분사계의 개변압에 따른 연료 미립화 특성 변화 = Variation of fuel atomization characteristics with opening pressure of P-L-N diesel injection system / 이장희.
발행사항 [대전 : 한국과학기술원, 2003].
Online Access 원문보기 원문인쇄

소장정보

등록번호

8014278

소장위치/청구기호

학술문화관(문화관) 보존서고

DME 03001

휴대폰 전송

도서상태

이용가능

대출가능

반납예정일

리뷰정보

초록정보

A series of experiments have been performed to examine the phenomenon of the after injection of diesel fuel at the closing stage of the needle motion in a single-spring diesel injector. Spray behavior at the final stage of a diesel injection from a single-hole injector was examined. As the result, the after-injection and the dripping phenomena were observed at the final stage of injection, which may cause generation of the unburned hydrocarbons or the particulate materials. Needle bouncing within the injector was detected and turned out to be the major reason for the after-injection. Both the amplitude and the frequency of the needle bouncing increased with the increase of valve-opening pressure. When the valve-opening pressure was increased, spray became more dispersed compared to the case with the lower valve-opening pressure. The amount of the fuel discharged during the after-injection period also increased with the increase of valve-opening pressure. On the other hand, the dripping of the liquid fuel was suppressed when the ambient pressure was increased. Spray drop sizes at the final stage of an injection were measured by using the Malvern particle sizer. When the valve opening pressure was raised, the spray drops became finer. On the other hand, spray drops became coarser with the increase of the ambient pressure from 1 MPa to 2 MPa. In overall, the atomization performance was improved, but only marginally with the increase of the valve-opening pressure due to occurrence of the after-injection phenomenon. A simplified analytical model has been proposed to describe the needle bouncing which was confirmed to be the primary cause of the after injection. The needle motion was well simulated by the proposed model. A series of parametric studies have been performed to see the effects of injector design parameters (such as damping coefficients, spring stiffnesses, equivalent stiffnesses, maximum needle lift and needle diameters). The needle bouncing tends to be supressed with the larger damping coefficient by the fluid shear at the needle surface. The needle bouncing can be reduced also by decreasing the material stiffness, initial displacement of the needle spring, equivalent stiffnesses of the needle seat and the injector body, and the maximum needle lift. Finally, the possibility of optimizing the injector design has been discussed for reduction of the after injection phenomenon.

서지기타정보

서지기타정보
청구기호 {DME 03001
형태사항 xii, 114 p. : 삽도 ; 26 cm
언어 한국어
일반주기 저자명의 영문표기 : Jang-Hee Lee
지도교수의 한글표기 : 이상용
지도교수의 영문표기 : Sang-Yong Lee
수록잡지명 : "Bouncing of the diesel injector needle at the closing stage". Proc. instn. mech. engrs. part D. : automobile engineering, v. 216 no. 8, pp.691-700 (2002)
학위논문 학위논문(박사) - 한국과학기술원 : 기계공학전공,
서지주기 참고문헌 : p. 110-114
주제 Diesel Injection System
Opening Pressure
Atomization
bouncing
디젤 분사계
개변압
미립화
바운싱
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