Study on the Cycle-by-Cycle Variation in Diesel Engines

Abstract

In order to study the cycle-by-cycle variations of combustion in a diesel engine, a continuous data acquisition system utilizing the analog computing circuits was developed and its accuracy was verified satisfactorily. Preliminary experiment proved that the amount of injected fuel per cycle could be measured indirectly by the integrated value of the injection nozzle lift. Then, applying the whole system to a two-stroke diesel engine, the necessary data including the indicated mean effective pressure etc. were collected and analyzed statistically. The result indicates that the irregularity of amount of injected fuel per cycle, which is subjected to the varying characteristics of the injection system concerned, mainly governs the variation of the indicated mean effective pressure.