On the study of fluid entry by solid objects and bubble column dynamics

Abstract

This research addresses the fluid-entry behavior of falling rigid bodies—specifically cylindrical disks and spheres—impacting a quiescent ambient fluid. With direct relevance to natural and engineered systems. The study resolves how variations in fluid properties such as fluid density, viscosity, and object geometry such as diameter, thickness, and edge profile, and the solid–fluid density ratio shape the entry process. Such entry processes are including splash/crown formation, cavity growth and pinch-off, added-mass effects, penetration trajectories, and the mixing field that develops behind the body. Framing the analysis with non-dimensional Froude, Reynolds, and Archimedes numbers. The study reveals the dominant scaling laws and furnish predictive correlations for impact-driven flow motion and mixing. Different fluids and mixtures were prepared to study the behavior of falling solid object in accordance with the variations in viscosity and yield stress. Several methods such as image analysis techniques, and flow measurement were implemented using in-house algorithms and MATLAB software codes to extract the required information for solid object movement, deceleration, crown geometries, and pinch-off time. The outcomes indicate that the behavior of the sinking solid object reveals valuable information about the dependence of the criteria that play an important role in the dynamics of the sinking objects. Additionally, the dynamics of rising bubble is investigated. The dynamics and characteristics of bubbles vary due to the properties of both solid objects and the ambient fluid. The influence of flow rates is investigated in a wide range, which could be nominated as a proper representative of many of its applications.