Modeling Free-Surface Flow in Part-Filled Rotating Vessels: Vertical and Horizontal Orientations

2003 ◽  
Vol 125 (6) ◽  
pp. 1022-1032 ◽  
Author(s):  
K. S. Sujatha ◽  
M. F. Webster

This paper reports on the numerical simulation of rotating flows with free surfaces, typically that arise in dough-kneading situations found within the food processing industry. Free-surface flow in a rotating cylinder is investigated when a fluid is stirred in a cylindrical-shaped vessel with a stirrer attached to its lid. The problem is posed in a three-dimensional cylindrical polar frame of reference. Numerical predictions are based on a Taylor-Galerkin/pressure-correction finite element formulation, with particle tracking to accommodate free-surface movement. Peeling and wetting conditions are incorporated to predict fluid-surface movement in contact with solid boundaries. Free-surface profiles are presented for different speeds of rotation and predictions compare closely to equivalent experimental results. The algorithmic implementation is validated against Newtonian analytical solutions. Typical results are presented to demonstrate the difference between Newtonian and inelastic model fluids.

2014 ◽  
Vol 15 (3) ◽  
pp. 517-524 ◽  
Author(s):  
Jalal Bazargan ◽  
Behrouz Aghebatie

Uniform flow will become unstable when the channel slope is very steep. When this happens, the free surface will form a series of roll waves. This paper, using the Fluent software and applying the volume of fluid model to simulate free surface flow and the k – ε turbulence model, analyzes conditions for roll wave formation in free surface flow with the aim of predicting their occurrence in chutes. This study describes how the type of cross-section of the chutes influences the formation of roll waves. Hydraulic characteristics of the flow in the physical model of the flood control structure for Azad Dam spillway, which consists of a side spillway, chute, and flip, are three-dimensionally simulated. Numerical predictions were compared against the experimental data and results show that there is a good agreement between numerical and experimental results. Results indicate that an increase in side slope tends towards flow stability and the slower formation of rolling waves. Also, the rolling waves are expected to be generated for sections of the chute when the difference between the maximum dynamic pressure and the minimum dynamic pressure in those sections is above 9,000 Pa.


Fluids ◽  
2021 ◽  
Vol 6 (10) ◽  
pp. 367
Author(s):  
Valentin Ageorges ◽  
Jorge Peixinho ◽  
Gaële Perret ◽  
Ghislain Lartigue ◽  
Vincent Moureau

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.


Author(s):  
Costel Ungureanu ◽  
Costel Iulian Mocanu

"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."


2021 ◽  
Vol 147 (3) ◽  
pp. 04021002
Author(s):  
Caterina Torres ◽  
Duncan Borman ◽  
Andrew Sleigh ◽  
David Neeve

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