Numerical Simulation Of Combustion Process And Characteristics In Aviation Piston Engine

The study of the combustion process and characteristics has been a focus in the study of pistonengine。It is not only help to understand the combustion mechanism, but also help to predict theperformance of the piston engine. And, it also can provide guidance for the pre-study of a new enginedesign or the performance improvement of the old engine.The research content of this article is divided into two parts. First of all, using the method ofnumerical simulation to find the way to improve the power performance of the four-stroke gasolineengine; Secondly, to make a comparative analysis of the difference of using gasoil and kerosene forthis engine. Finally, take a further research on the kerosene engine with difference parameters.The main work and innovation are showed as follows:A geometric model which has little difference from the original machine is built. The angle ofvalve overlap is taken into consideration, which is closer to the real physical simulation. In order toimprove the calculation precision most details are taken into account when the dynamic grid ismeshing. Finally, a three-dimensional CFD model was established and a test was carried out to makesure the model was valid.The result of simulation shows that using double spark plugs can effectively improve thedynamic performance of the gasoil engine. Put forward3schemes of how to put the two spark plugs,and find out the optimal one which has the best power performance for the engine. The in-cylinderpressure has approximate linear increase with the rise of inlet pressure. The gasoil engine has thestrongest power performance when the air coefficient is one.When using gasoil as the fuel, the average combustion rate is higher and the ignition delayperiod is shorter than kerosene, under the same boundary conditions, and the power will have anobviously loss if the kerosene directly used on the gasoil engine. The power of the kerosene enginewill be restored effectively by increasing the ignition advance angle. Especially, when he ignitionadvance Angle is greater than30°CA, the post burning phenomenon will decrease obviously. Thepower of the kerosene engine will be restored effectively by increasing the ignition energy, but theinfluence will be decreased gradually with the improvement of the ignition energy.The research achievements of this paper can provide some useful advices for the study oftransform a gasoline aviation piston engines into using kerosene.