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. (c) 2007 Elsevier Ltd. All rights reserved.