A SIMPLE OIL-WATER EXPERIMENT TO VERIFY OIL QUALITY
Kalimuthu Swaminathan
Keywords: Spreading, Hole nucleation, Hole Growth, Hole Coalescence, film coarsening, Oil quality, miscible constituents.
Abstract
Natural oil films and their dynamics on water are interesting to many applications like oil spills on sea and in coating stability. The dynamics of such natural oil films on water is the subject of this experimental study. In this paper a simple oil-water dynamics experiment is proposed to identify oil type and quality, by characterizing the spreading and dewetting process of an oil film on water. Experiments have been performed with gingelly oil, olive oil, castor oil and coconut oil. In each experiment a drop of test fluid (one of the natural oils) is placed gently on the surface of water. The spreading patterns of the oil film was recorded was recorded and analyzed. In all cases, it was observed that the natural oil drop spreads spontaneously on the free surface of water. Subsequently, number of holes are observed to form on the spreading front of oil film. When the hole count reaches the particular limit called random packing limit, holes start to merge with the adjacent holes, and this process continues and results to a coarser structure of the oil films. This process is quantified initially using spreading rate. The general path traced by the centroid were also shows a radially outward. Therefore, the spreading and hole formation process is modelled using potential flow theory. Pseudo color images of the all the modelled holes predicting the movement of the spreading front meniscus to some extent. Furthermore, It was also found that the all the measure of holes displacement shows an increase in randomness as the holes count reaches towards random packing limit.