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Velocity measurements have been made in a motored engine intended for direct injection spark ignited (DISI) operation. Previous experiments showed the effect of intake gas velocities on direct injection spray plumes in this engine, without directly quantifying the gas velocities involved. This work documents the intake velocities in the vicinity of the spray plume, although the spray was not present in these experiments. The measurements were made using an LDV system. Two velocity components were measured, though not simultaneously, through two orthogonal windows in the cylinder of an optical engine equipped with a head designed for DISI engine use. This engine had 4-valves and a pent-roof; the injector (when installed) was positioned slightly off-center in the head, with the spark plug located near by.

The instantaneous two dimensional velocity fields around the intake valve of an internal combustion engine were experimentally investigated by means of particle image velocimetry. The measurements were taken in a plane perpendicular to a cylinder head near the intake valve in a simulated engine setup using a diesel engine cylinder head and an acrylic cylinder with glass optical windows. The intake valves were actuated by a motor driven cam. The measurements at various cam rotating speeds and valve lifts were made to investigate the unsteady effects of the intake valve flow. For comparison of dynamic and static valve flows, measurements with stationary valves were also conducted. The instantaneous two dimensional flow fields showed a well organized intake jet, and entrainment of the ambient air into the jet. For the same valve lift and pressure drop across the intake valves, the static valve flow showed higher jet velocity than the dynamic intake valve flow.