Assessing the Working-Cycle Fluctuation in Internal-Combustion Engines from the Nonuniformity of the Idling Speed

摘要

In practice, it is important to assess the nonuniformity of the crankshaft speed in internal combustion engines. In such assessments, the sensitivity of the chosen criteria to the following factors is of particular interest: the spread of the maximum pressure; and the spread in the operational characteristics in successive working cycles. In the present work, the criteria and operational characteristics are calculated in idling. A unique relation between the deviations in successive working cycles and the nonuniformity of the crankshaft speed is only possible in idling [1]. The following criteria are considered: the variation in the increment in crankshaft speed over the cycle in a sequence of operational cycles; the variation of the maximum crankshaft speed (its amplitude); the variation of the set of maximum and minimum crankshaft speeds; and the relation between the real and kinematic nonuniformity of the crankshaft speed.