Study On Phenomenological Model Of Cross-Collision Between Spray Jets

The multi-injector system has been widely used in marine low-speed machine,and it also has good application prospect in medium-speed machine.The advantage of using multi-injector system is that it can obviously improve thermal efficiency,however,the cross-mixing and interference of multi-bunches of fuel oil will occur in the cylinder,which leads to the complicated temporal and spatial distribution of fuel spray in the cylinder.The main research goal of this paper is to study the phenomenon of the crossing of two oil bundles in space,the spray atomization,mixing,ignition and combustion characteristics of the cross-fuel Bundle in the cylinder caused by multiple injection of the multi-injector are analyzed in order to control the combustion rate and regulate the fuel injection law,realize the application of controllable combustion technology,and finally achieve the goal of energy saving and emission reduction.In this study,computer programming is used to carry out simulation modeling,and numerical simulation is carried out for the interference problem of space and time caused by the space cross-beam injection in the cylinder,then provides the theory reference for the follow-up correlation experiment.The phenomenological model of single-bundle Diesel fuel based on empirical formula is established,and the spray sub-model and combustion sub-model are established respectively Then,based on the traditional single-beam fuel spray and combustion model,it is improved to reflect the mixed interference of two fuel bundles,the improvement of the model includes three parts: the first part is to establish a single-beam fuel spray model based on the probability distribution in the spray model,the second part is to calculate the initial velocity of the diesel fuel bundle after it is broken using the conservation of energy method.The third part is based on the actual air resistance of the diesel fuel bundle in the cylinder,the velocity distribution of small droplets in diesel fuel spray is obtained by using gas resistance formula,and the velocity distribution of diesel fuel spray is obtained according to the initial velocity after breaking;The probability distribution density based single-beam model is then extended to the case where the two oil beams interfere with each other,and the Monte Carlo method is used to determine whether the two oil beams interfere with each other,if so,then,the time-domain relationship of the mixing zone is calculated by using the two-dimensional geometric algorithm,and the air entrainment sub-model and combustion sub-model of the two-bundle mixing are established Finally,at the ambient temperature of 900 K,3/6/9 MPA ambient pressure,50/75/100 mm nozzle spacing and30/45/60 degree injection angle were selected to explore the law of combustion effect,the optimized heat release rate curves under different influence factors are analyzed.The results show that under the same conditions,the higher the ambient pressure,the larger the distance between the nozzle holes and the smaller the injection angle,the heat release rate curve is the most consistent.