Large eddy simulation of turbidity currents in a narrow channel with different obstacle configurations

Goodarzi, Danial; Lari, Kaveh Sookhak; Khavasi, Ehsan; Abolfathi, Soroush

doi:10.1038/s41598-020-68830-5

Cited by 34 publications

(12 citation statements)

References 73 publications

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“…The advantage of DNS is that it can provide more accurate results prior to the other two methods, but it requires a lot of computational resources. By comparison, LES gives relatively satisfactory results with less computational cost, which makes it widely adopted (Kyrousi et al 2018;Goodarzi et al 2020;Koohandaz et al 2020;Pelmard, Norris & Friedrich 2018). In recent years, the coupled model of solving individual particle motion with the discrete element method (DEM) and fluid motion has been widely used to simulate two-phase flows, such as Schmeeckle (2014), Sun & Xiao (2016), Jing et al (2016), Maurin, Chauchat & Frey (2018), Pähtz & Durán (2018a), Pähtz & Durán (2018b), Pähtz & Durán (2020) and Zhu et al (2020).…”

Section: Introductionmentioning

confidence: 99%

Turbidity currents propagating down an inclined slope: particle auto-suspension

Xie

Zhu

et al. 2023

J. Fluid Mech.

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The turbidity current (TC), a ubiquitous fluid–particle coupled phenomenon in the natural environment and engineering, can transport over long distances on an inclined terrain due to the suspension mechanism. A large-eddy simulation and discrete element method coupled model is employed to simulate the particle-laden gravity currents over the inclined slope in order to investigate the auto-suspension mechanism from a Lagrangian perspective. The particle Reynolds number in our TC simulation is $0.01\sim 0.1$ and the slope angle is $1/20 \sim 1/5$ . The influences of initial particle concentration and terrain slope on the particle flow regimes, particle movement patterns, fluid–particle interactions, energy budget and auto-suspension index are explored. The results indicate that the auto-suspension particles predominantly appear near the current head and their number increases and then decreases during the current evolution, which is positively correlated with the coherent structures around the head. When the turbidity current propagates downstream, the average particle Reynolds number of the auto-suspension particles remains basically unchanged, and is higher than that of other transported particles. The average particle Reynolds number of the transported particles exhibits a negative correlation with the Reynolds number of the current. Furthermore, the increase in particle concentration will enhance the particle velocity, which allows the turbidity current to advance faster and improves the perpendicular support, thereby increasing the turbidity current auto-suspension capacity. Increasing slope angle will result in a slightly larger front velocity, while the effect of that on the total force is insignificant.

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Section: Introductionmentioning

confidence: 99%

Turbidity currents propagating down an inclined slope: particle auto-suspension

Xie

Zhu

et al. 2023

J. Fluid Mech.

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“…The numerical model is developed in an open-source numerical platform, OpenFOAM, designed for numerically solving continuum mechanic problems based on a tensorial approach and three-dimensional finite-volume method (FVM). Reynolds-averaged Navier-Stokes (RANS) equations are used as the governing equations for fluid motion [19]. The continuity equation and momentum equation for incompressible fluid is adopted as:…”

Section: A Numerical Modelling Approachmentioning

confidence: 99%

The Effects of Porous Baffles on the Hydraulic Performance of Sediment Retention Ponds — A Numerical Modelling Study

Guo¹,

Goodarzi²,

Borzooei³

et al. 2022

IJESD

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This study develops a numerical model for investigating the hydraulic characteristics of a retention pond with porous baffles. The numerical model is developed using the Reynolds-averaged Navier-Stokes equations (RANS) with k-εturbulence closure model. The model is successfully validated using physical modelling measurements. The proposed model is used to investigate the key mechanisms that govern and influence the hydraulic efficiency of retention ponds with porous baffles. Three configurations with varying numbers and locations of baffles are simulated. The numerical results are analyzed by comparison of velocity fields, tracer transport patterns, and associated residence time distributions (RTDs) across all the simulation scenarios. It was found that the porous baffles effectively improve hydraulic performance by creating uniform flow distribution and dissipating the flow energy, thereby avoiding dead zones and mitigating short-circuiting. Results show that the location of the first baffle plays a critical role in the flow momentum dissipation. Carefully considerations are required to determine the optimal number and positions of baffles in a specific system. The numerical RTDs are in good agreement with the physical modelling data, confirming the positive contribution of porous baffles to the overall hydraulic performance of the pond by extending the average tracer residence time.

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“…Multi-phase flows in many environmental and industrial processes are subject to nonlinear and complex changes in the flow regime, composition of different phases, temperature and pressure fluctuations [40] , [41] , [42] , [43] , [44] . These nonlinearities in multi-phase flow systems are further intensified due to the existence of disturbance sources, the effects of environmental conditions, and specifications of the multi-phase flow system.…”

Section: Introductionmentioning

confidence: 99%