Study on In-Cylinder Flow Field Using Particle Image Velocimtry

摘要

In this paper, an apprratus simulating air flow process during intake, comrpression and expansion. stroke in a four-stroke engine was developed, which was especially suitable for measurement of whole field flow velocity using particle image velocimetry (PIV). The PIV films were processed on a specially developed PIV film processing system. Instantaneous in-plane velocity fields were measured and were further processed using high-and low-pass filtering techniques. Vorticity distribution was also calculated. Vortex structure of the flow field was clearly visualized. Incylinder flow energy was found decaying at high rate but the smaller scale flow components at low rate. Squish was found effecting mainly the smaller scale flow energy.