Coupled Dynamics of a Solid Piercing a Fluid Free Surface

2002 ◽  
Author(s):  
Remus M. Ciobotaru ◽  
Razvan Bidoae ◽  
Peter E. Raad
Keyword(s):  
Fluid Flow ◽  
Free Surface ◽  
Surface Deformation ◽  
Stokes Equations ◽  
Initial Conditions ◽  
Three Dimensional ◽  
Free Surface Flow ◽  
Surface Flow ◽  
Second Phase ◽  
Submerged Sphere

This paper reports on numerical investigations of the dynamics of a moving sphere interacting with free surface flow in a three-dimensional, rectangular, confined channel. Each simulation consists of two phases. During the first phase, the sphere is fixed and the fluid flow around it is allowed to reach a stationary state. In the second phase, the sphere is allowed to oscillate vertically. The Froude number is shown to influence the dynamics of the sphere. Also, the influence of three different initial positions on the dynamics of the sphere are presented and discussed. The first initial condition corresponds to a surface-piercing sphere while the second and the third conditions correspond to a submerged sphere at two different depths beneath the free surface. The drag coefficient computed for the two initial conditions involving a fully submerged sphere is compared with the experimental (published) values for a sphere in an unbounded domain. The motion of the fluid flow around the moving solid body is based on the solution of the complete Navier-Stokes equations. The free surface deformation is solved by the use of an Eulerian-Lagrangian Marker and Micro Cell (ELMMC) method.

scholarly journals A Hybrid Parallel Numerical Model for Wave-Induced Free-Surface Flow

Fluids ◽  
2021 ◽  
Vol 6 (10) ◽  
pp. 350
Author(s):  
Georgios A. Leftheriotis ◽  
Iason A. Chalmoukis ◽  
Guillermo Oyarzun ◽  
Athanassios A. Dimas
Keyword(s):  
Free Surface ◽  
Numerical Model ◽  
Large Scale ◽  
Stokes Equations ◽  
Parallel Implementation ◽  
Three Dimensional ◽  
Free Surface Flow ◽  
Free Surface Flows ◽  
Surface Flow ◽  
Wave Induced

An advanced numerical model is presented for the simulation of wave-induced free-surface flow, utilizing an efficient hybrid parallel implementation. The model is based on the solution of the Navier–Stokes equations using large-eddy simulation of large-scale coastal free-surface flows. The three-dimensional immersed boundary method was used for the enforcement of the no-slip boundary condition on the bed surface. The water-air interface was tracked using the level-set method. The numerical model was effectively validated against laboratory measurements involving wave propagation over a flatbed with an elliptical shoal, whose presence induces combined wave refraction and diffraction phenomena. The parallel implementation of the model enabled the efficient simulation of depth-resolved, wave-induced, three-dimensional, free-surface flow; the model parallel efficiency and strong scaling are quantitatively demonstrated.

A Numerical Framework for Free Surface Flow and Wettability Based on Arbitrary Lagrange-Eulerian Method

2013 ◽  
Vol 787 ◽  
pp. 1080-1084
Author(s):  
Zuo Sheng Lei ◽  
Xiao Xing Jin ◽  
Chao Yue Chen ◽  
Yun Bo Zhong ◽  
Zhong Ming Ren
Keyword(s):  
Fluid Flow ◽  
Free Surface ◽  
Sessile Drop ◽  
Free Surface Flow ◽  
Mathematic Model ◽  
Surface Flow ◽  
Moving Mesh ◽  
Incompressible Fluid Flow ◽  
Electrowetting On Dielectric ◽  
Eulerian Method

A mathematic model based on moving mesh Arbitrary Lagrange-Eulerian (ALE) is developed to solve incompressible fluid flow concerned with the free surface and wettability. A mercury sessile drop with different wetting angles is chosen to validate this method. Besides, two more extensive applications called electrowetting-on-dielectric (EWOD) and transferred drop are numerically simulated and compared with previous researchers work in order to demonstrate its efficiency.

scholarly journals Experiments and Simulations of Free-Surface Flow behind a Finite Height Rigid Vertical Cylinder

Fluids ◽  
2021 ◽  
Vol 6 (10) ◽  
pp. 367
Author(s):  
Valentin Ageorges ◽  
Jorge Peixinho ◽  
Gaële Perret ◽  
Ghislain Lartigue ◽  
Vincent Moureau
Keyword(s):  
Free Surface ◽  
Numerical Study ◽  
Three Dimensional ◽  
Vertical Cylinder ◽  
Free Surface Flow ◽  
Air Entrainment ◽  
Surface Flow ◽  
Finite Height ◽  
Wave Patterns ◽  
Different Diameters

We present the results of a combined experimental and numerical study of the free-surface flow behind a finite height rigid vertical cylinder. The experiments measure the drag and the wake angle on cylinders of different diameters for a range of velocities corresponding to 30,000 <Re< 200,000 and 0.2<Fr<2 where the Reynolds and Froude numbers are based on the diameter. The three-dimensional large eddy simulations use a conservative level-set method for the air-water interface, thus predicting the pressure, the vorticity, the free-surface elevation and the onset of air entrainment. The deep flow looks like single phase turbulent flow past a cylinder, but close to the free-surface, the interaction between the wall, the free-surface and the flow is taking place, leading to a reduced cylinder drag and the appearance of V-shaped surface wave patterns. For large velocities, vortex shedding is suppressed in a layer region behind the cylinder below the free surface. The wave patterns mostly follow the capillary-gravity theory, which predicts the crest lines cusps. Interestingly, it also indicates the regions of strong elevation fluctuations and the location of air entrainment observed in the experiments. Overall, these new simulation results, drag, wake angle and onset of air entrainment, compare quantitatively with experiments.

scholarly journals Influence of the hydrofoil inclination angle at free surface flow around junctions

2020 ◽  
Vol 43 ◽  
pp. 103-108
Author(s):  
Costel Ungureanu ◽  
Costel Iulian Mocanu
Keyword(s):  
Boundary Layer ◽  
Free Surface ◽  
Bluff Body ◽  
Three Dimensional ◽  
Free Surface Flow ◽  
Breaking Waves ◽  
Surface Flow ◽  
Vortex Structures ◽  
The Body ◽  
Flow Topology

"Free surface flow is a hydrodynamic problem with a seemingly simple geometric configuration but with a flow topology complicated by the pressure gradient due to the presence of the obstacle, the interaction between the boundary layer and the free surface, turbulence, breaking waves, surface tension effects between water and air. As the ship appendages become more and more used and larger in size, the general understanding of the flow field around the appendages and the junction between them and the hull is a topical issue for naval hydrodynamics. When flowing with a boundary layer, when the streamlines meet a bluff body mounted on a solid flat or curved surface, detachments appear in front of it due to the blocking effect. As a result, vortex structures develop in the fluid, also called horseshoe vortices, the current being one with a completely three-dimensional character, complicated by the interactions between the boundary layer and the vortex structures thus generated. Despite the importance of the topic, the literature records the lack of coherent methods for investigating free surface flow around junctions, the lack of consistent studies on the influence of the inclination of the profile mounted on the body. As a result, this paper aims to systematically study the influence of profile inclination in respect to the support plate."

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