Numerical model of common rail electromagnetic fuel injector

Abstract

The injection process in diesel engines has influence on the in-cylinder combustible mixture formation, ignition, combustion, and exhaust of emissions. Modern diesel engine injection system is under strict requirements to fulfil the purpose to not only reduce the fuel consumption but also the exhaust emissions and noise levels. The Common Rail injection system gives engine developers the possibility to reduce both exhaust emissions and engine noise. The Common Rail (CR) fuel injection system allows accurately regulatingof the fuel injection rate, the rate of fuel discharge from the nozzle holes, distribution and timing with the engine operating within a wide range of loads and speeds. The CR fuel injection system with piezo or electromagnetic nozzles speeds up the nozzle opening and closing, allowing adjusting the injection pressure, injection rate and atomization characteristics. This paper presents numerical modelling of injection characteristics in a diesel engine. The numerical model was performed by using AVL BOOST Hydsim fluid dynamic simulation. The experiment results were compared with the numerical ones. The injection characteristics were measured and analysed using the injection rate measuring system. The injection rate, injection quantity per cycle, injection delay, and injection duration were analysed across a range of injection pressure and injection energizing time. The comparison of the results shows that the numerical model is reliable and the results of the numerical model are close to the experimental test results.