High-resolution simulations of gravity currents

Birman, V. K.; Meiburg, Eckart

doi:10.1590/s1678-58782006000200006

Cited by 6 publications

(9 citation statements)

References 5 publications

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“…This behavior is characteristic of the slumping phase of the flow, as discussed in [7,8,12,14]. Note although that Ooi's results are for a Grashof number Gr = 1.25×10 6 . In Table I.…”

mentioning

confidence: 70%

“…In these experiments, we set Gr = 1.5×10 6 and Sc = 0.71 following [7,8,10,12]. Figure 2 shows the results for three different representative …”

Section: Planar Lock Exchangementioning

confidence: 99%

“…The initial radius of the heavier fluid is r 0 = 2.0 and the unstructured grid was built with 2 125 139 tetrahedra, 2 607 939 edges and 390 527 nodes. Following the planar case and References [10,12,46], the Grashof and Schimdt numbers are Gr = 1.5×10 6 and Sc = 0.71. We employed in this simulation the SUPG/PSPG formulation for the flow and the SUPG formulation with Y Z with full residual for the density fluctuation.…”

Section: Cylindrical Lock Exchangementioning

confidence: 99%

“…However, there has been an increasing use of numerical methods to model gravity currents, mainly due to the growth in the computational resources and the development of efficient numerical software in the past decades. Most of these numerical studies have focused on structured grids and spectral methods employing a direct numerical simulation (DNS) approach where even the fine scales of the flow are represented [6][7][8][9][10][11]. Recently, a comprehensive study on the dynamics of the front velocity during the different phases of spreading, namely, acceleration, slumping, inertial and viscous phases, has been carried out by Cantero et al [12].…”

Section: Introductionmentioning

confidence: 99%

“…[13] 3D DNS [12] Figure 4. Head position evolution in the planar problem for Gr = 1.5×10 6 and Sc = 0.71. Figure 4, we also include the experimental results of Shin et al [4].…”

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confidence: 99%

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Stabilized edge‐based finite element computation of gravity currents in lock‐exchange configurations

Elias

Paraizo

Coutinho

2008

Numerical Methods in Fluids

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SUMMARYModeling of gravity current flows is important in many problems of science and engineering. Gravity currents are primarily horizontal flows driven by a density difference of few per cents. This phenomenon occurs in many scales in nature, such as ocean and marine flows, sea breeze formation, avalanches, turbidite flows, etc. Most of the gravity current simulations employ structured grid or spectral methods. In this work, we simulate gravity-driven flows by a parallel stabilized edge-based finite element code with particular emphasis on the simulation of the lock-exchange problem for planar and cylindrical configurations. Our results are validated against other highly resolved numerical simulations and experiments.

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“…This behavior is characteristic of the slumping phase of the flow, as discussed in [7,8,12,14]. Note although that Ooi's results are for a Grashof number Gr = 1.25×10 6 . In Table I.…”

mentioning

confidence: 70%

“…In these experiments, we set Gr = 1.5×10 6 and Sc = 0.71 following [7,8,10,12]. Figure 2 shows the results for three different representative …”

Section: Planar Lock Exchangementioning

confidence: 99%

Section: Cylindrical Lock Exchangementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…[13] 3D DNS [12] Figure 4. Head position evolution in the planar problem for Gr = 1.5×10 6 and Sc = 0.71. Figure 4, we also include the experimental results of Shin et al [4].…”

mentioning

confidence: 99%

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Stabilized edge‐based finite element computation of gravity currents in lock‐exchange configurations

Elias

Paraizo

Coutinho

2008

Numerical Methods in Fluids

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Rankine models for time‐dependent gravity spreading of terrestrial source flows over subplanar slopes

et al. 2014

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Geological mass flows extruding from a point source include mud, lava, and salt issued from subsurface reservoirs and ice from surface feeders. The delivery of the material may occur via a salt stock, a volcanic pipe (for magma and mud flows), or a valley glacier (for ice). All these source flows are commonly skewed by a superposed far-field velocity vector imposed by the topographic slope and thus develop plumes having a wide range of shapes. The morphological evolution of the perimeter of the plumes (in plan view) can be simulated by varying the key parameters in a simple analytical flow description on the basis of Rankine equations. Our model systematically varies the strength of the point source relative to the downslope far-field velocity of its expelled mass. The flow lines are critically controlled by the relative speed of the two rates, which can be concisely expressed by the dimensionless Rankine number (Rk, introduced in this study). For steady flows, plume widths can be expressed as a function of Rk. The viscosity of the rock, mud, or lava mass involved in the gravity flow affects Rk and thus the appearance of the plumes. For unsteady source strength, Rk becomes time dependent and the plume width varies over time. The model flow shapes suggest that the plume shapes of natural gravity flows of terrestrial surface materials (mud, lava, salt, and ice) commonly express fast initial flux of the source, followed by an exponential decline of the source strength. Flows having initially higher Rk but otherwise equal life cycles create broader plumes. Peaks in the source flux due to magmatic pulsing during the eruption cycle can explain the formation of pillow lavas. Rather than instantaneously reaching full strength before declining, some natural source flows start by swelling slowly, leading to the creation of unique plume shapes like a flying saucer.

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The effect of Schmidt number on gravity current flows: The formation of large-scale three-dimensional structures

et al. 2021

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The Schmidt number, defined as the ratio of scalar to momentum diffusivity, varies by multiple orders of magnitude in real world flows, with large differences in scalar diffusivity between temperature, solute, and sediment driven flows. This is especially crucial in gravity currents, where the flow dynamics may be driven by differences in temperature, solute, or sediment, and yet the effect of Schmidt number on the structure and dynamics of gravity currents is poorly understood. Existing numerical work has typically assumed a Schmidt number near unity, despite the impact of Schmidt number on the development of fine-scale flow structure. The few numerical investigations considering high Schmidt number gravity currents have relied heavily on two-dimensional simulations when discussing Schmidt number effects, leaving the effect of high Schmidt number on three-dimensional flow features unknown. In this paper, three-dimensional direct numerical simulations of constant-influx solute-based gravity currents with Reynolds numbers 100 ≤ Re ≤ 3000 and Schmidt number 1 are presented, with the effect of Schmidt number considered in cases with (Re, Sc) = (100, 10), (100, 100), and (500, 10). This data is used to establish the effect of Schmidt number on different properties of gravity currents, such as density distribution and interface stability. It is shown that increasing Schmidt number from 1 leads to substantial structural changes not seen with increased Reynolds number in the range considered here. Recommendations are made regarding lower Schmidt number assumptions, usually made to reduce computational cost.

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High-resolution simulations of gravity currents

Cited by 6 publications

References 5 publications

Stabilized edge‐based finite element computation of gravity currents in lock‐exchange configurations

Stabilized edge‐based finite element computation of gravity currents in lock‐exchange configurations

Rankine models for time‐dependent gravity spreading of terrestrial source flows over subplanar slopes

The effect of Schmidt number on gravity current flows: The formation of large-scale three-dimensional structures

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