Study on engineering application method of large-scale reaction mechanism in knock prediction

In this paper, a new engineering application method for gasoline engine knock prediction in a quasi-dimensional combustion model using a large-scale reaction mechanism is explored. First, an accelerated calculation strategy coupled with 1D calculation and large-scale reaction kinetics mechanism was developed to meet the needs of rapid automatic simulation in engineering. Secondly, a gasoline surrogate was created according to the test results of China 92# gasoline. The motor octane number (MON) and the research octane number (RON) values, which were closely related to knock, were calibrated using the detailed reaction mechanism. Then, the prediction of auto-ignition of unburned region was carried out combined with predicted burn rate model and cycle to cycle variation (CCV) model. The relationship between the experimental in-cylinder pressure oscillation and the simulated auto-ignition in the unburned region was established. The multi-conditions verification results of three engines with different displacement, compression ratio and combustion system arrangement show that the average errors of predicted knock CA50 are 1.6(circle)CA, 1.8(circle)CA and 1.9(circle)CA respectively.