Related Experiment Video
Updated: Dec 29, 2025
08:49
Impacts of Free-falling Spheres on a Deep Liquid Pool with Altered Fluid and Impactor Surface Conditions
Published on: February 17, 2019
6.9K
Simulations of a heavy ball falling through a sheared suspension
Adam K Townsend1, Helen J Wilson1
1Department of Mathematics, University College London, Gower Street, London, WC1E 6BT UK.
Journal of Engineering Mathematics
|February 4, 2020
Summary
Lateral oscillatory shear flow accelerates heavy sphere settling in particle suspensions. In concentrated suspensions, shear can even cause upward movement by forming and breaking repulsion chains.
Area of Science:
- Fluid dynamics
- Rheology of suspensions
- Particle-laden flows
Background:
- Experiments show heavy spheres accelerate in sheared suspensions.
- Upward movement of spheres observed in concentrated suspensions under shear.
- Understanding particle suspension behavior under external forces is crucial.
Purpose of the Study:
- To model heavy sphere motion in concentrated suspensions using Stokesian Dynamics.
- To investigate the influence of oscillation frequency and interparticle forces.
- To elucidate the mechanism behind observed sphere motion, including upward movement.
Main Methods:
- Utilizing Stokesian Dynamics simulations.
- Analyzing the motion of a heavy sphere within a suspension.
- Investigating the suspension microstructure evolution.
Main Results:
- Sphere motion and suspension microstructure depend on oscillation frequency and interparticle forces.
- A mechanism involving vertical repulsion chain formation and breakup is proposed.
- Simulations reproduce key experimental observations from Blanc et al. (2014).
Conclusions:
- Vertical repulsion chains offer a mechanism for enhanced settling and upward motion.
- Dimensionless parameters governing particle-fluid and interparticle interactions are identified.
- Stokesian Dynamics effectively models complex behaviors in sheared suspensions.
Related Concept Videos
01:15Thin-Walled Hollow Shafts
483
In analyzing a thin-walled hollow shaft subjected to torsional loading, a segment with width dx is isolated for examination. Despite its equilibrium state, this segment faces torsional shearing forces at its ends. These forces are quantitatively described by the product of the longitudinal shearing stress on the segment's minor surface and the area of this surface, leading to the concept of shear flow. This shear flow is consistent throughout the structure, indicating a uniform distribution of...
483
01:14Shearing Stresses in a Beam: Problem Solving
552
A cantilever beam with a rectangular cross-section under distributed and point loads experiences shearing stresses. The analysis begins by identifying the loads acting on the beam. Then, the reactions at the beam's fixed end are calculated using equilibrium equations. The vertical reaction is a combination of the distributed and point loads, while the moment reaction is the sum of their moments. The shear force distribution along the beam, resulting from these loads, is established by creating...
552
01:19Principle of Angular Impulse and Momentum: Problem Solving
422
Consider a ball of mass m, attached to a massless rod of known length, subjected to a time-dependent torque. If the initial velocity of the mass is known, then the final velocity of the mass for time t can be determined using the principle of angular impulse and momentum.
Initially, a free-body diagram of the system is drawn to illustrate all the forces acting upon the system, providing a crucial understanding of the dynamics at play. Then, the principle of angular impulse and momentum is...
Initially, a free-body diagram of the system is drawn to illustrate all the forces acting upon the system, providing a crucial understanding of the dynamics at play. Then, the principle of angular impulse and momentum is...
422
01:13Stability of Equilibrium Configuration: Problem Solving
903
The stability of equilibrium configurations is an important concept in physics, engineering, and other related fields. In simple terms, it refers to the tendency of an object or system to return to its equilibrium position after being disturbed. The stability of an equilibrium configuration can be analyzed by considering the potential energy function of the system and examining its behavior near the equilibrium point.
Problem-solving in the context of the stability of equilibrium configuration...
Problem-solving in the context of the stability of equilibrium configuration...
903
01:13Circular Shaft - Stresses in Linear Range
629
Consider a scenario where a circular shaft is subject to torque that remains within the boundaries of Hooke's Law, avoiding any permanent deformation. So, the formula for shearing strain is revisited. This formula is multiplied by the modulus of rigidity, and then Hooke's Law for the shearing stress and strain is applied. As a result, the equation for shearing stress in a shaft can be derived.
629
01:15Design of Transmission Shafts - Stress Analysis
683
Designing a transmission shaft requires a thorough understanding of the stresses induced by bending moments and torques, especially in systems where power is transferred through gears. These forces create force-couple systems at the centers of the shaft's cross-sections, leading to both transverse and torsional loading. Although shearing stresses from transverse loads are typically smaller than those from torques and are often overlooked, the significant normal stresses from these loads...
683