| description abstract | Abstract. Understanding the dynamics of particle dispersal in viscous environments, particularly in presence of an immiscible oil-water layer, is crucial for both environmental and industrial processes. This study investigates the behavior of single and twin oblique release of sand particles through two adjacent nozzles and their interactions, focusing on the influence of oil layer thickness, nozzle spacing, and aspect ratio on dynamics and cluster formation of sand particles. Oil layer thickness played a significant role in determining the variations in frontal width and the presence of a thicker oil layer leads to a wider spread of sand particles. The time variation of frontal velocity in twin release of sand particles was affected by both aspect ratio and oil layer thickness and higher aspect ratios resulted in an initial 25% increase in frontal velocity. Advanced cluster size distribution analysis combined with color-coding of clusters, according to their size, were performed to provide detailed information on particle and cluster dynamics. Experimental results indicated that the existence of an oil layer reduced the penetration depth by nearly 20%. Cluster size distribution analysis indicated that at the initial stage of evolution, a thicker oil layer caused the formation of relatively larger cluster sizes by approximately 30%. Smaller nozzle spacing exacerbated the channelization effect, leading to a change in smaller sand clusters from 40% to 60% indicating that cluster segregation and spreading enhances with the reduction of nozzle spacing. The combination of a thin oil layer and narrower nozzle spacing resulted in a smaller cluster formation, which is considered as higher cluster efficiency. | |
