Simulation Study On In-cylinder Working Process Of Opposite Piston Opposite Cylinder Engine

Opposite piston opposite cylinder engine is new concept engine proposed in recent years.In comparison with traditional engine, this engine has great advantages in economical,emission, power density and some other aspect of performance, also there is many technologyproblem need to be solved in R&D of this engine.This paper analyzed and summarized the OPOC engine working process, drawing ontheory and research method of traditional engine，simulating, analyzing and predicting theOPOC engine performance by three research content of1-D work process simulation,3-Dscavenging simulation and3-D combustion simulation, to support the optimized design ofOPOC engine performance.In the process of1-D simulation, the primary task is to solving the differential of1-Dmodel of OPOC engine and traditional engine, for building complete calculation model. Thispaper calculated OPOC equivalent piston motion, change of intake and exhaust ports flowarea, and other modules engine data different with conventional engine, to build a completemodel, so that the one-dimensional simulation result is more approach to real OPOC engineperformance and get the boundary conditions data for three-dimensional simulation.In the process of3-D scavenging process, this paper identify the key factors thatinfluence scavenging, simulate and analysis the scavenging quality in different operatingcondition and scavenge pressure difference, although the pressure difference with theoperating condition, but the influence of pressure difference is more intuitive. The research ofthis paper prove that at low speed, the pressure differential has little effect on scavengingefficiency, the large pressure difference result in loss of fresh air; at high speed, pressuredifference generate fluctuating change of scavenging quality and need more precision data forconfirm the best pressure difference. The formation of scavenge pressure difference isdependent on parameter of turbocharger, and hence optimization of scavenging is achieved bymatching the turbocharger.In the process of3-D combustion process, because of distinction between OPOC enginethe combustion process and the traditional engine the combustion process, combustion chamber and fuel injection program is more exploratory. According to the theoretical designprinciples, this paper design4kinds of combustion chamber and corresponding inject strategy,using simulation model build in original machine parameters to achieve optimized injectiontiming solution, after that, simulate the combustion process by using origin model and fourdesign model, analysis advantage and disadvantage of different combustion chamber.