Investigation on the process of injection of commercial grade and blended fuel in a diesel engine

Abstract

Purpose. A computational valuation of the parameters of the process of commercial grade and blended fuel flow in the injector nozzle of a locomotive diesel engine, and its impact on spraying conditions in the combustion chamber. Methodology. The scientific investigation is based on using the technique of a comparative numerical experiment. Modern numerical methods in computational fluid dynamics are used for simulating fuel flow and spraying processes in the injector nozzle and combustion chamber. Findings. It was found that when working with commercial grade fuel with maximum pressure in the area of the injector well of 85MPa, the fuel flow velocity in the fuel injection nozzle hole reaches 434 m/s, whereas when working with fuel blended with alcohol the velocity decreases to 429 m/s (at a 25% alcohol concentration). Due to the lower pressure of saturated vapours of the blended fuel, as compared to that of commercial grade fuel, the fuel-air mixing conditions degrade at the operating duty being investigated. Originality. The investigation helped to study the impact of blended fuel composition on changes in the processes of its flow in the injector nozzle, and on the injection into the combustion chamber and the fuel-air mixing conditions. The study results helped to develop recommendations on ensuring effective ICE operation with blended fuel. Practical value. A change in the conditions of blended fuel spraying and fuel-air mixing should be taken into account when choosing effective fuel injection advance angles and fueling principles in order to ensure high ICE economic and ecological performance.