【作者】

Ansgar Ratzke，Christoph Hennecke

【摘要】

论文已在中国上海举行的第27届CIMAC大会上发表。论文的版权归CIMAC所有。 Simulation is an important approach for the design of internal combustion engines. Zonal cylinder models are able to depict the essential physical and chemical processes of internal combustion. In this contribution, such a zonal cylinder model for calculating the rate of heat release of a methane gas IC engine is developed and implemented with a graphical programming language. This model divides the combustion chamber into zones described by properties of state like pressure, temperature, mass, and volume.At the beginning of each iterative simulation step, the model distinguishes the zone of unburnt gas from the zone of burnt gas. The combustion solely takes place in a third region called reaction zone which separates the zone of burnt gas from the unburnt gas, while the combustion process is modelled with an intermediate third balance zone. The volume of this reaction zone is assumed to be proportional to the current flame surface area and the turbulent flame speed. Theturbulent flame speed is approximated from the lami-nar flame speed and with the help of a pressure-and temperature-dependent approach proposed by Muppala et al. Furthermore, the flame surface gets deformed by the piston movement. This geometry is described as an ellipsoid of revolution, taking into account, that some areas of this ellipsoid might hit the walls of the combustion chamber. Here local flame extinction appears.A model by Boust et al. is implemented to calculate the quenching distance between flame and wall surface. This quench model bases on the balance of the heat release rate and wall heat flux.The amount of quenched methane gas is derived from the quenched volume. The achievement is a simple model requiring little computing time of just few seconds. The simulated rate of heat release meets the demand of sufficient precision on the one hand and of fewest equations on the other hand. The model approach allows analyzing a major source of the unburnt methane pollutant from such gas engines.

【会议名称】

第27届CIMAC会议

【会议地点】

上海

【下载次数】

1

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