G0700603 Study on Flow Visualization of Oil Film : Photochromism of Oil

Abstract

A new method for visualization of oil film flow is proposed in this study. We are aiming to visualize oil film by dissolving a photochromic dye in lubricating oil and coloring with UV ray. This paper explains the photochromism of oil and the applicability to measurement of oil film thickness and flow visualization. Firstly, we examined the suitable oil for visualization because the condensation of colored photochromic dye was confirmed in the conventional test oil, PAO. As a result, ester oil, which has relatively high polarity, was obtained as the suitable lubricating oil for visualization. Secondly, we tested this method in the wedge-shaped oil film to quantify oil film thickness. Consequently, it was confirmed that the oil film thickness can be quantified from the absorption of light caused by photochromism. We also confirmed the change of color with time and obtained the relatively long colored lifetime of photochromism. Finally, flow visualization was tried in the flow channel made thickness approximately ten micrometers. The test oil flowing through this flow channel was colored with a third harmonic of Nd-YAG laser. The oil film flow was visualized with the help of image processing.