Measurement of Fuel Liquid Film under the Different Injection Pressure 2013-32-9167

The purpose of this study was to measure the distribution and volume of liquid film adhering to the walls after the injection of fuel by an injector of a port-injection engine using the laser induced fluorescence (LIF) method while changing the fuel pressure and the angle of injection, and to consider how adhesion can be reduced in order to decrease the exhaust emission of gasoline engine. Using a high-speed camera, we filmed the adhesion and evaporation of liquid film in time series. Perylene, used here as a fluorescence dye, was blended with a fuel comprising toluene and n-heptane, and the mixture was injected onto a solid surface using a port-injection injector. UVLED with a maximum output wavelength of 375 nm was used as the exciting light. To more accurately measure the volume of fuel adhesion, it was necessary to correct the unevenness of the light source. For this purpose, we filmed the unevenness of the light source using a fluorescent plate, and using the image as the reference, corrected the images of liquid film adhesion. Through these methods, we evaluated the behavior of liquid film under different injection pressures and injection angles. The results showed that by increasing the fuel pressure, we can reduce the liquid film adhesion and that the smaller the angle of injection, the larger the effect.