Multi methods for combustion instability analysis of Atkinson cycle engine based on time series analysis

Abstract

Researching the combustion instability of ACE is meaningful no matter for HEVs development or for combustion control of the Atkinson cycle. Based on a gasoline ACE, EGR sweeping tests are conducted and thermodynamics time series are obtained. CCV is calculated versus cycle numbers for dominant thermal parameters. According to the acquired time series, PSR, RP, and RQA methods are employed to analyse chaotic characteristics and combustion instability. Through the current investigation, the influence of EGR on ACE combustion instability is studied with the largest IMEP variation of 13.6% at EGR valve fully opened condition. The effect on the combustion centre is much larger than SOC. Time series RPs depict abundant structures representing determinism, laminarity, and other characteristics corresponding to the typical chaos character of the unstable system. Beyond typical measures of RQA, two new quantitative indicators are proposed to quantify fluctuation property. Besides, CCV analysis based on multiple time series is employed as a supplement explanation to emphasize correlations characters and a new PCC analysis method is first proposed and evaluated efficiently to research instability with intuitiveness and simplicity. In conclusion, combustion instability is researched which provides guidance for ACE technology, combustion instability analysis is enriched by classical and newly proposed single or multi time series based analysis methods.