A comparison of numerical methods for non-Newtonian fluid flows in a sudden expansion

Ilio, Giovanni Di; Chiappini, Daniele; Bella, Gino

doi:10.1142/s0129183116501394

Cited by 21 publications

(12 citation statements)

References 46 publications

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“…The lattice Boltzmann methods (LBM) [1,2,3,4,5,6] are a relatively recent approach to computational fluid dynamics (CFD), which has been proven to be successful in a broad range of applications, from turbulence [7,8,9], to multiphase and free-surface flows [10,11], as well as to non-Newtonian flows [12], fluid-structure interaction problems [13], porous media [14,15,16] and beyond. The original formulation of LBM is based on uniform cartesian grids.…”

Section: Introductionmentioning

confidence: 99%

Fluid flow around NACA 0012 airfoil at low-Reynolds numbers with hybrid lattice Boltzmann method

et al. 2018

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We simulate the two-dimensional fluid flow around National Advisory Committee for Aeronautics (NACA) 0012 airfoil using a hybrid lattice Boltzmann method (HLBM), which combines the standard lattice Boltzmann method with an unstructured finite-volume formulation. The aim of the study is to assess the numerical performances and the robustness of the computational method. To this purpose, after providing a convergence study to estimate the overall accuracy of the method, we analyze the numerical solution for different values of the angle of attack at a Reynolds number equal to 10 3 . Subsequently, flow fields at Reynolds numbers up to 10 4 are computed for a zero angle of attack configuration. A grid refinement scheme is applied to the uniformly spaced component of the overlapping grid system to further enhance the numerical efficiency of the model. The results demonstrate the capability of the HLBM to achieve high accuracy near solid curved walls, thus providing a viable alternative in the realm of off-lattice Boltzmann methods based on body-fitted mesh.

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Section: Introductionmentioning

confidence: 99%

Fluid flow around NACA 0012 airfoil at low-Reynolds numbers with hybrid lattice Boltzmann method

et al. 2018

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“…There are no results available for the non-Newtonian power-law fluids in a backward-facing step while 100 ≤ Re ≤ 400, so it is not possible to show a direct comparison for the code validation. Instead of the backward-facing step, for the power-law fluids, (n = 0.6, 1.0, 1.5), a qualitative comparison is shown in terms of the streamlines with the results of power-law non-Newtonian fluids flow in a sudden expansion channel obtained by Ilio et al [65] and depicted in Figure 8. Here the boundary conditions, the aspect ratio of the inlet and channel height (H/d = 3.0, where H is the channel height and d is the length of the inlet), and the length of the upstream and downstream regions are kept as same as Ilio et al [65].…”

Section: Flow In a Backward-facing Stepmentioning

confidence: 89%

“…Instead of the backward-facing step, for the power-law fluids, (n = 0.6, 1.0, 1.5), a qualitative comparison is shown in terms of the streamlines with the results of power-law non-Newtonian fluids flow in a sudden expansion channel obtained by Ilio et al [65] and depicted in Figure 8. Here the boundary conditions, the aspect ratio of the inlet and channel height (H/d = 3.0, where H is the channel height and d is the length of the inlet), and the length of the upstream and downstream regions are kept as same as Ilio et al [65]. Based on Ilio et al [65] study, the lattice size 1120 × 96 is chosen for this comparison.…”

Section: Flow In a Backward-facing Stepmentioning

confidence: 89%

“…Here the boundary conditions, the aspect ratio of the inlet and channel height (H/d = 3.0, where H is the channel height and d is the length of the inlet), and the length of the upstream and downstream regions are kept as same as Ilio et al [65]. Based on Ilio et al [65] study, the lattice size 1120 × 96 is chosen for this comparison. From these figures, it can be concluded that the comparison showed a good agreement.…”

Section: Flow In a Backward-facing Stepmentioning

confidence: 99%

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A Graphics Process Unit-Based Multiple-Relaxation-Time Lattice Boltzmann Simulation of Non-Newtonian Fluid Flows in a Backward Facing Step

et al. 2020

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A modified power-law (MPL) viscosity model of non-Newtonian fluid flow has been used for the multiple-relaxation-time (MRT) lattice Boltzmann methods (LBM) and then validated with the benchmark problems using the graphics process unit (GPU) parallel computing via Compute Unified Device Architecture (CUDA) C platform. The MPL model for characterizing the non-Newtonian behavior is an empirical correlation that considers the Newtonian behavior of a non-Newtonian fluid at a very low and high shear rate. A new time unit parameter (λ) governing the flow has been identified, and this parameter is the consequence of the induced length scale introduced by the power law. The MPL model is free from any singularities due to the very low or even zero shear-rate. The proposed MPL model was first validated for the benchmark study of the lid-driven cavity and channel flows. The model was then applied for shear-thinning and shear-thickening fluid flows through a backward-facing step with relatively low Reynolds numbers, Re = 100–400. In the case of shear-thinning fluids (n=0.5), laminar to transitional flow arises while Re≥300, and the large vortex breaks into several small vortices. The numerical results are presented regarding the velocity distribution, streamlines, and the lengths of the reattachment points.

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“…Thanks to several improvements made in the last two decades, the LBM has revealed to be an accurate and efficient tool for modelling several complex fluid dynamics problems that could be of interest also for agricultural engineering, such as multiphase and multi-component flows, free-surface flows, flows in porous media, fluid-structure interaction, and micro-fluidics (Succi et Ubertini et al, 2004;Falcucci et al, 2007;Colosqui et al, 2012;De Rosis et al, 2013;Falcucci et al, 2010Falcucci et al, , 2013Zarghami et al, 2014aZarghami et al, , 2014bChiappini et al, 2015;Di Francesco et al, 2015;Di Ilio et al, 2016Krastev et al, 2016), including applications to complex geometries (Chiappini, 2015;Di Ilio et al, 2016;Krastev et al, 2016) and LBM extensions to non-regular and unstructured grids (Ubertini et al, 2004;Zarghami et al, 2014aZarghami et al, , 2014bDi Ilio et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

Multi-component Lattice Boltzmann simulation of the hydrodynamics in drip emitters

Falcucci

Krastev

Biscarini

2017

J Agricult Engineer

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In this paper, we propose a fast and efficient numerical technique based on the Lattice Boltzmann method (LBM) to model the flow through a reference drip emitter geometry. The aim of the study is to demonstrate the applicability of the LBM as a reliable simulation tool for the hydraulic optimisation of irrigation systems. Results for the water flow through a rectangular drip emitter are in good agreement with literature numerical and experimental data. Furthermore, we demonstrate the feasibility of the proposed model to simulate a multi-component flow that could be used to simulate the presence of additives, contaminants, and suspended particles. IntroductionAs shown in several studies, drip emitters play a major role in the hydraulic performance of drip irrigation systems (Glaad, 1974;Ozekici et al., 1991; Carraro et al., 2006;Li et al., 2006). Glaad (1974) reports several results obtained under laboratory conditions and highlights the effect of structural form, dimension and material of emitter channels on the overall performance of the dripper. In Ozekici et al. (1991), pressure losses during water flow are related to the shape of the emitter channel.However, a detailed experimental observation of the flow pattern through emitter channels has proven to be practically unfeasible, due to their complex shape and very small size (less than 1 mm 2 of cross sectional area). This provides the typical framework in which computational fluid dynamics (CFD) can be proficiently employed (Xia and Sun, 2002;Lee, 2013;Lee et al., 2013), to allow an experimental-based optimisation of drip irrigation systems. To date, a few CFD applications to drip emitters can be reported in the scientific literature, all based on well established numerical techniques such as the finite volume method (FVM) or the finite element method (FEM) (Palau-Salvador et al., 2004;Wei et al., 2004Wei et al., , 2006Provenzano et al., 2007;Li et al., 2008;Wu et al., 2013;Yurdem et al., 2015). In Palau-Salvador et al. (2004), a finite volume laminar flow model is employed to investigate the pressure vs discharge rate correlation in a straight channel design, showing a good agreement with experimental data. In Wei et al. (2004) a novel channel design is simulated numerically, confirming that the use of CFD can effectively reduce the number of experimental samples and measurements. The FEM method is applied in Wei et al. (2006), under a turbulent flow assumption, to explore its reliability in the comparison of several labyrinth channel designs. Wu et al. (2013) analyse the effectiveness of the standard k-ε model and the large eddy simulation (LES) method in simulating the fluid dynamics inside drip irrigation emitters and concluded that the LES model is more effective.A potential candidate for the direct simulation (i.e., without turbulence modelling) of fluid flow in the micro-channels of drip emitters is the Lattice Boltzmann method (LBM), a powerful technique for the computational modelling of a wide variety of complex fluid flow problems (Benzi e...

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A comparison of numerical methods for non-Newtonian fluid flows in a sudden expansion

Cited by 21 publications

References 46 publications

Fluid flow around NACA 0012 airfoil at low-Reynolds numbers with hybrid lattice Boltzmann method

Fluid flow around NACA 0012 airfoil at low-Reynolds numbers with hybrid lattice Boltzmann method

A Graphics Process Unit-Based Multiple-Relaxation-Time Lattice Boltzmann Simulation of Non-Newtonian Fluid Flows in a Backward Facing Step

Multi-component Lattice Boltzmann simulation of the hydrodynamics in drip emitters

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