동적 격자를 이용한 중속 디젤엔진 연료분사펌프의 캐비테이션 현상에 관한 수치해석

Abstract

Recently the fuel injection pressure of diesel engines becomes increased more and more for improvement of combustion efficiency and decrease of smoke emissions at the same time. Due to increasing of fuel injection pressure, the damage by cavitation is a major cause in decreasing the life of fuel injection pump. Most of the existing studies on the cavitation in fuel injection pump were optical observations. Therefore, it could be efficient to investigate for reducing method of cavitation in fuel injection pump using computational fluid dynamics (CFD). The object model was 210 kW per cylinder fuel injection pump manufactured by P. Corporation. The fuel injection system, mainly plunger and barrel were modeled by Ansys Fluent R15.0 and the major object of observation components were plunger and barrel. Dynamic mesh and user-defined function (UDF) were used for modeling of plunger movement. Effects of inlet pressure on cavitation were investigated according to increase of inlet pressure (3.5, 5.5 and 7.5 bar). Consequently, increase of inlet pressure was desirable to decrease cavitation in fuel injection pump.