Investigation of deterministic and random cyclic patterns in a conventional diesel engine using symbol sequence analysis

Abstract

Current study focuses on cyclic variability analysis of indicated mean effective pressure (IMEP) and total heat release (THR) in a conventional single cylinder diesel engine using symbol sequence statistics. The objective is to characterize the cyclic variations and estimate the deterministic pattern in experimental data series. Results presented in this study can be beneficial for the design of effective control strategy. Experiments are performed at constant speed for five different engine operating conditions. Engine cylinder pressure data is acquired for 2500 consecutive cycles. Engine combustion parameters (IMEP and THR) are calculated from measured cylinder pressure on cycle to cycle basis and resulting data series is analyzed by symbol sequence method. Results revealed that selection of symbol sequence length and number of partitions is dependent on engine operating conditions and chosen combustion parameter.