The Simulation Of The Charge Motion And Spray Field In Cylinder Of The Four-stroke Engine

The design of the direct injection combustion system for spark-ignition kerosene piston enginehas an influence on the performance on cold-start, operation stability in the entire speed and loadconditions, and the maximum power loss of the knock limit. Therefore it is important to do theresearch on the CFD-aid design of the direct injection combustion system for spark-ignition kerosenepiston engine.In this paper，the numerical simulation of the charge motion and the spray for the improvedengine which had wedge chamber and used the carburetor to form the mixture have been done, andthe design and optimization of the air-assisted injector will also be done according to the relevantliterature. The research content is that followed.1. The numerical simulation of the steady flow test of the intake port has been done, the result ofCFD simulation is consistent with the trend of the experiment results and the deviation is small,which Verified the correctness of the CFD method. And the CFD method can be used to improve thedesign of the combustion system.2.Completed the numerical transit simulation of the prototype and improved engines by using thetechnology of dynamic mesh, got the information on transit behavior of the charge motionin-cylinder as basis for future improvement.3.According to the relevant literature and patents, completed optimization of the air-assistedinjector and the numerical simulation of the spray. The result of CFD simulation is consistent withthe experiment results and the deviation is small.4.Completed the transit simulation of the spray in-cylinder, and the research the influence ofcharge motion on the spray.The results of this paper provide important theory and numerical basis for the design andoptimization of the air assisted injector and the direct injection systems, which also supplied apractical method for the future improvement, compared to the experiment method, this method willsave a lot of time and cost.