Miloš Jovanović

FUNCTION K - AS A LINK BETWEEN FUEL FLOW VELOCITY AND FUEL PRESSURE, DEPENDING ON THE TYPE OF FUEL

Regarding the application of vegetable oil based fuels in diesel engines, it is necessary to fully examine and understand the processes which take place in fuel delivery systems, namely, the processes of injection, mixture formation and combustion as well as emission characteristics. The paper provides an analysis of fuel flow in high pressure tubes of the fuel injection system, with the aim of determining function K as a link between fuel flow velocity and fuel pressure, and observing the influence of certain physical characteristics of the fuel upon the given function. The analysis presents the speed of sound and density, as fuel characteristics which affect the K function. The paper determines the speed of sound, density and bulk modulus for four fuels (pure rapeseed oil RO, biodiesel B100, a mixture of biodiesel and diesel B50, and diesel D), and forms appropriate K functions for each fuel in the pressure range from the atmospheric one to 1600 bar.