scholarly journals Cascaded lattice Boltzmann modeling and simulations of three-dimensional non-Newtonian fluid flows

2021 ◽  
Vol 262 ◽  
pp. 107858
Author(s):  
Saad Adam ◽  
Farzaneh Hajabdollahi ◽  
Kannan N. Premnath
Keyword(s):  
Newtonian Fluid ◽  
Lattice Boltzmann ◽  
Three Dimensional ◽  
Fluid Flows ◽  
Modeling And Simulations ◽  
Lattice Boltzmann Modeling

Modeling and Simulations of Deteriorated Turbulent Heat Transfer in Wall-Heated Cylindrical Tube

2019 ◽  
Vol 4 (3) ◽  
Author(s):  
Prasad Vegendla ◽  
Rui Hu
Keyword(s):  
Heat Transfer ◽  
Nuclear Power ◽  
Three Dimensional ◽  
Cylindrical Tube ◽  
Fluid Flows ◽  
Turbulent Heat Transfer ◽  
Wall Region ◽  
Turbulent Heat ◽  
Modeling And Simulations ◽  
Computational Fluid Dynamics Cfd

Abstract This paper discusses the modeling and simulations of deteriorated turbulent heat transfer (DTHT) for a wall-heated fluid flows, which can be observed in gas-cooled nuclear power reactors during pressurized conduction cooldown (PCC) event due to loss of force circulation flow. The DTHT regime is defined as the deterioration of normal turbulent heat transport due to increase of acceleration and buoyancy forces. The computational fluid dynamics (CFD) tools such as Nek5000 and STAR-CCM+ can help to analyze the DTHT phenomena in reactors for efficient thermal-fluid designs. Three-dimensional (3D) CFD nonisothermal modeling and simulations were performed in a wall-heated circular tube. The simulation results were validated with two different CFD tools, Nek5000 and STAR-CCM+, and validated with an experimental data. The predicted bulk temperatures were identical in both CFD tools, as expected. Good agreement between simulated results and measured data were obtained for wall temperatures along the tube axis using Nek5000. In STAR-CCM+, the under-predicted wall temperatures were mainly due to higher turbulence in the wall region. In STAR-CCM+, the predicted DTHT was over 48% at outlet when compared to inlet heat transfer values.

Challenges on Porting Lattice Boltzmann Method on Accelerators

2018 ◽  
pp. 30-53 ◽  
Author(s):  
Claudio Schepke ◽  
João V. F. Lima ◽  
Matheus S. Serpa
Keyword(s):  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
High Performance ◽  
Three Dimensional ◽  
Fluid Flows ◽  
Xeon Phi ◽  
Performance Impact ◽  
Operation Rules ◽  
Dimensional Version ◽  
Boltzmann Method

Currently NVIDIA GPUs and Intel Xeon Phi accelerators are alternatives of computational architectures to provide high performance. This chapter investigates the performance impact of these architectures on the lattice Boltzmann method. This method is an alternative to simulate fluid flows iteratively using discrete representations. It can be adopted for a large number of flows simulations using simple operation rules. In the experiments, it was considered a three-dimensional version of the method, with 19 discrete directions of propagation (D3Q19). Performance evaluation compare three modern GPUs: K20M, K80, and Titan X; and two architectures of Xeon Phi: Knights Corner (KNC) and Knights Landing (KNL). Titan X provides the fastest execution time of all hardware considered. The results show that GPUs offer better processing time for the application. A KNL cache implementation presents the best results for Xeon Phi architectures and the new Xeon Phi (KNL) is two times faster than the previous model (KNC).

scholarly journals Three-Dimensional Lattice Boltzmann Modeling of Dendritic Solidification under Forced and Natural Convection

Metals ◽  
2017 ◽  
Vol 7 (11) ◽  
pp. 474 ◽  
Author(s):  
Mohsen Eshraghi ◽  
Mohammad Hashemi ◽  
Bohumir Jelinek ◽  
Sergio Felicelli
Keyword(s):  
Natural Convection ◽  
Lattice Boltzmann ◽  
Three Dimensional ◽  
Dendritic Solidification ◽  
Dimensional Lattice ◽  
Lattice Boltzmann Modeling

scholarly journals Large-scale lattice Boltzmann simulations of complex fluids: advances through the advent of computational Grids

2005 ◽  
Vol 363 (1833) ◽  
pp. 1895-1915 ◽  
Author(s):  
Jens Harting ◽  
Jonathan Chin ◽  
Maddalena Venturoli ◽  
Peter V Coveney
Keyword(s):  
Lattice Boltzmann ◽  
Large Scale ◽  
Three Dimensional ◽  
Fluid Flows ◽  
Scientific Work ◽  
Computational Grids ◽  
Computational Steering ◽  
Lattice Boltzmann Simulations ◽  
Complex Fluid ◽  
Visualization Techniques

During the last 2.5 years, the RealityGrid project has allowed us to be one of the few scientific groups involved in the development of computational Grids. Since smoothly working production Grids are not yet available, we have been able to substantially influence the direction of software and Grid deployment within the project. In this paper, we review our results from large-scale three-dimensional lattice Boltzmann simulations performed over the last 2.5 years. We describe how the proactive use of computational steering, and advanced job migration and visualization techniques enabled us to do our scientific work more efficiently. The projects reported on in this paper are studies of complex fluid flows under shear or in porous media, as well as large-scale parameter searches, and studies of the self-organization of liquid cubic mesophases.

Numerical Study of Newtonian Fluid Flows in T-Shaped Structures with Impermeable Walls

2019 ◽  
Vol 396 ◽  
pp. 177-186
Author(s):  
Vinicius da Rosa Pepe ◽  
Luiz Alberto Oliveira Rocha ◽  
Flavia Schwarz Franceschini Zinani ◽  
Antonio Ferreira Miguel
Keyword(s):  
Steady State ◽  
Newtonian Fluid ◽  
Numerical Study ◽  
Three Dimensional ◽  
Fluid Flows ◽  
Reynolds Numbers ◽  
Geometric Constraints ◽  
Constructal Theory ◽  
3D Structures ◽  
Constructal Design

This article presents the results of flows in "T" shaped duct bifurcations. The problem is to find the resistance to flow in three-dimensional (3D) structures with different homothetic relationships between sizes (diameters and lengths) of parent and daughter ducts. The method used is the Constructal Design, which is based on the Constructal Theory. The minimization of the global resistance to flow, subjected to geometric constraints of volume and area occupied by the ducts, is the key to search for optimum configurations. The flows investigated were three-dimensional, laminar, incompressible, in steady state, with uniform and constant properties. The results obtained numerically were verified via comparison with analytical results available in the literature. In this work, ranges of length and ratio of diameterss from 0.5 to 1 and 0.1 to 1, respectively, were investigated, for Reynolds numbers equal to 102 and 103. The main results indicate that the T-shaped structure with impermeable walls, agree with Hess-Murray's law.

A Lattice Boltzmann and Immersed Boundary Scheme for Model Blood Flow in Constricted Pipes: Part 1 - Steady Flow

2013 ◽  
Vol 14 (1) ◽  
pp. 126-152 ◽  
Author(s):  
S. C. Fu ◽  
W. W. F. Leung ◽  
R. M. C. So
Keyword(s):  
Blood Flow ◽  
Newtonian Fluid ◽  
Lattice Boltzmann ◽  
Numerical Scheme ◽  
Flow Behavior ◽  
Three Dimensional ◽  
Complex Problem ◽  
Immersed Boundary ◽  
Cartesian Grids ◽  
Boltzmann Method

AbstractHemodynamics is a complex problem with several distinct characteristics; fluid is non-Newtonian, flow is pulsatile in nature, flow is three-dimensional due to cholesterol/plague built up, and blood vessel wall is elastic. In order to simulate this type of flows accurately, any proposed numerical scheme has to be able to replicate these characteristics correctly, efficiently, as well as individually and collectively. Since the equations of the finite difference lattice Boltzmann method (FDLBM) are hyperbolic, and can be solved using Cartesian grids locally, explicitly and efficiently on parallel computers, a program of study to develop a viable FDLBM numerical scheme that can mimic these characteristics individually in any model blood flow problem was initiated. The present objective is to first develop a steady FDLBM with an immersed boundary (IB) method to model blood flow in stenoic artery over a range of Reynolds numbers. The resulting equations in the FDLBM/IB numerical scheme can still be solved using Cartesian grids; thus, changing complex artery geometry can be treated without resorting to grid generation. The FDLBM/IB numerical scheme is validated against known data and is then used to study Newtonian and non-Newtonian fluid flow through constricted tubes. The investigation aims to gain insight into the constricted flow behavior and the non-Newtonian fluid effect on this behavior.

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