Study On Ignition Process Stability Of Engine Premixed Turbulent Combustion

Nowadays,energy shortage and environmental pollution are becoming more and more serious,and the small cycle variations of the initial nuclear generation and development has a great impact on the engine power output and emission characteristics.In order to investigate the effects of ignition energy,ignition advance angle,excess air coefficient and flow intensity of engine cylinder ignition process stability,based on the 1E65 FM engine simulated calculation and experimental research.Using ANSYS software Fluent module,and based on the reaction mechanism of isooctane simplified simulation ignition energy,ignition advance angle,excess air coefficient and cylinder turbulence intensity influence on the ignition process,and through self-matlab program to process the simulation results,the factors affecting the initial kernel radius on the initial kernel formation stage of the nuclear fire,the radius of the fire nuclear development stage of the growth rate,the ignition delay period and ignition effect of fire nuclear surface of fold.The simulation results show that the ignition energy is increased from 50 mJ to 150 mJ,initial kernel radius and kernel development stage of the nuclear fire growth rate increasing,the ignition delay decreases gradually,enhance the stability of the ignition process,effects of ignition energy on the development stage of the nuclear fire as fire nuclear generating phase significantly;the ignition advance angle on the initial kernel formation stage had little effect,with the ignition angle decreased from 20 degrees to 10 degrees,the critical radius of nuclear fire and ignition delay period decreases,enhance the stability of the ignition process but the fire nuclear development period nuclear growth rate gradually increased;in the optimal excessive air coefficient value of 0.9,the fire nuclear development period the maximum growth rate,the critical radius of the smallest nuclear fire ignition,the ignition delay period is the shortest,the ignition process is the best,the excess air coefficient influence on initial nuclear fire generated as fire nuclear development is obvious;the in cylinder turbulence intensity and speed is proportional to the relationship,and in the ignition process of turbulence intensity decreases,as the speed of the engine increases from 1500r/min to 2500r/min,initial kernel radius is basically the same,the development of nuclear fire flame kernel growth rate decreases gradually,the ignition process reduced stability.In this paper,a visual modification of 1E65 FM engine is designed,and a set of schlieren system and visualization system is designed.Influence of ignition process on the stability of the experimental study of different engine speed,the experimental results show that the speed has little impact on initial kernel;the lower the speed,better power engine,the ignition delay time is short,the ignition process is more stable.