带有内嵌体通道中润滑油流动的显微PIV测量
Grease is commonly used to lubricate various machine components such as rolling elementbearings, open gears etc. Better understanding of the flow properties of grease will contribute tounderstanding the lubrication mechanism in bearings and flow in lubrication systems. In an earlier paperMicro Particle Image Velocimetry (μPIV) techniques were used to study the flow in a rectangular channel.The present paper is an extension of this work where restrictions were applied in such a channel, whichcreates a much more complex velocity field. The grease is seeded with fluorescent particles, which areilluminated by a double-pulsed laser. The test geometries that are used in this study are a channel with oneflat restriction and one with two flow restrictions in a similar channel. The stationary grease mass-flow andthe two dimensional velocity fields have been monitored for different pressure drops. For the channel withone flat restriction, the flow was measured to be symmetric at the inlet and outlet, and the distance for theflow to fully develop is comparable with the height of the channel Slow motion was followed near the stepcorner at the inlet. For the channel with two flow restrictions, the vector profiles show that the maximumvelocity appears at the restrictions In-between the two restrictions, a part of the grease is not moving. Thisparticularly applies to cases with low-pressure drop and where high consistency grease was used.