Unsteady Flow in the Induction System of a Reciprocating Internal Combustion Engine

Pressure-time variations are recorded in the intake pipe and crankcase of a motored, crankcase compression, piston ported, loop scavenged two stroke cycle engine over a range of engine speeds from 2000-7000 rpm, for several intake pipe lengths and different inlet port timings. These pressure-time histories are presented together with the results of theoretical calculations, which include unsteady flow in the induction tract.

Predicted delivery ratio trends are compared with measured values over the range of engine speeds and inlet tract lengths for different inlet port timings.