Analysis of cycle-to-cycle pressure oscillations in a diesel engine

In this paper we study the fluctuations of mean indicated pressure (MIP) in a diesel engine. Using recurrence plots, recurrence quantification analysis and continuous wavelet transform, we investigate the cycle-to-cycle pressure variations for six rotational speeds of the crankshaft. We find that depending on the speed of rotation, the pressure variations may have a strongly periodic component and/or be intermittent. The strong periodicities appear in low-frequency bands and may persist over many cycles, whereas the intermittency is present at higher frequencies. The results may be useful to develop effective control strategies for efficient engine performance.