Experimental Study of Diesel Engine Cycle-to-Cycle Variation—Part III

Abstract

Marine diesel engine excitation can occur from the cycle-to-cycle variation in the engine output. The cycle-to-cycle variation in maximum cylinder pressure (Pmax) is often used to represent this variation. Earlier studies examined the correlation between the cycle-to-cycle variation in the maximum cylinder pressure (Ρmax), pressure impulse (PI) and ignition delay (ID) for the case of constant injection setting. This paper summarizes the results of systematic experiments to determine the cycle-to-cycle variations when the injection timing is changed. In these tests the cycle-to-cycle variations in the maximum cylinder pressure (Pmax), ignition delay (ID), and corresponding pressure impulse (PI) are examined for a single-cylinder test diesel engine at various speeds and compression ratios. Comparisons show that the cycle-to-cycle variations of the diesel engine power output are strongly affected by the injection timing. The best parameter for describing the cycle-to-cycle output variation is shown to depend on the specific engine test condition.