An Investigation of Valve Lift Effect on Air Flow and Coefficient of Discharge of Four Stroke Engines Based on Experiment

Abstract

The coefficient of discharge (CD) is defined as the ratio of actual discharge to ideal discharge. In an engine environment, ideal discharge considers an ideal gas and the process to be free from friction, surface tension, etc. Coefficients of discharge are widely used to monitor the flow efficiency through various engine components and are quite useful in improving the performance of these components. The flow through engines it is equally important to have accurate values for coefficients of discharge through the combinations of valves, ports and ducts. In this experiment investigation of air flow and coefficient of discharge are desirable for inflow (reverse flow) through the exhaust port using SuperFlow Flowbench. The coefficients of discharge the diesel engines can be quite measured under steady flow conditions for a range of pressures and flows. This paper presents experimental results for air flow and coefficient of discharge investigating the intake and exhaust flow of four stroke direct injection diesel engines. The CD measurements are shown for various pressures, valve lift per diameters (L/D) ratio conditions at the intake port pipe to cylinder and cylinder to exhaust port pipe geometries.