Technical Paper
Two-Dimensional In-Cylinder Flow Field in a Natural Gas Fueled Spark Ignition Engine Probed by Particle Tracking Velocimetry and Its Dependence on Engine Specifications
1999-05-03
1999-01-1534
An experimental study was made to investigate in-cylinder flow field in a natural gas fueled spark ignition engine and the effects of engine specifications on in-cylinder flow field. The instantaneous two-dimentional flow fields in a single-cylinder visualization engine, which has 75mm bore and 62mm stroke, were measured in various cross sections perpendicular to the cylinder axis by using the laser light sheet PTV method at various crank angles during intake, compression, and expansion strokes over the wide range of piston combustion chamber configuration, top clearance, and nominal swirl ratio. Flow fields during compression and expansion strokes were also calculated using KIVA2 simulation code for better understanding of the measured results. The results showed that induction-generated swirl is getting concentric to the cylinder center in compression stroke, and is shifted in the radial direction in expansion stroke.