Numerical Analysis of Flow and Heat Transfer at a Backward-Facing Step With an Obstacle Based on Lattice Boltzmann Method

2016 ◽  
Author(s):  
Insaf Mehrez ◽  
Ramla Gheith ◽  
Fethi Aloui ◽  
Sassi Ben Nasrallah
Keyword(s):  
Heat Transfer ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Expansion Ratio ◽  
Physical Parameters ◽  
Backward Facing Step ◽  
Flow Problems ◽  
Flow And Heat Transfer ◽  
Recirculation Length ◽  
Boltzmann Method

The Lattice Boltzmann method is actually considered as one of the simplest approach. The flow and heat transfer distribution in a duct containing a backward and an obstacle are studied for different geometric and physical parameters. The LBM is applied to solve the backward-facing step flow problems for an expansion ratio H/h = 2 in rectangular duct and to determine the effect of the obstacle on flow and heat transfer distribution. The obstacle is situated in the bottom wall of the duct. The effect of various obstacle lengths (0.5<h/S<1.5) will be also considered. All this results were observed for a Prandtl number of 0.71 and different range of Reynolds number (1–200). This study showed the instabilities of velocity, recirculation length, temperature and Nusselt number with the obstacle downstream the step. These results were compared to with published experimental.

SIMULATION OF FLUID FLOW AND HEAT TRANSFER IN A PLANE CHANNEL USING THE LATTICE BOLTZMANN METHOD

2003 ◽  
Vol 17 (01n02) ◽  
pp. 183-187 ◽  
Author(s):  
G. H. TANG ◽  
W. Q. TAO ◽  
Y. L. HE
Keyword(s):  
Heat Transfer ◽  
Distribution Function ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Plane Channel ◽  
Parallel Plates ◽  
Thermal Boundary Conditions ◽  
Flow And Heat Transfer ◽  
Forced Convective Flow ◽  
Boltzmann Method

Forced convective flow and heat transfer between two parallel plates are studied using the lattice Boltzmann method (LBM) in this paper. Three kinds of thermal boundary conditions at the top and bottom plates are studied. The velocity field is simulated using density distribution function while a separate internal energy distribution function is introduced to simulate the temperature field. The results agree well with data from traditional finite volume method (FVM) and analytical solutions. The present work indicates that LBM may be developed as a promising method for predicting convective heat transfer because of its many inherent advantages.

Very-Large Eddy Simulations of Disk Heat Transfer in a Rotating Cavity Using Lattice-Boltzmann Method

2018 ◽  
Author(s):  
J. Kouwa ◽  
Y. Iso ◽  
F. Polidoro ◽  
S. Gautier
Keyword(s):  
Heat Transfer ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Three Dimensional ◽  
Flow Structures ◽  
Physical Parameters ◽  
Transfer Coefficients ◽  
Experimental Heat ◽  
Large Eddy ◽  
Boltzmann Method

Convective heat transfer in the cavity between two corotating disks is of great importance for turbomachinery applications. The complex three dimensional and unsteady flow structures induced by the Coriolis forces inside the cavity, and therefore the resulting heat transfer, are challenging to be measured in an experiment or predicted by simulation. In this paper a simplified cavity geometry, characterized experimentally by Long at al., has been chosen. The results obtained with a Very Large Eddy Simulation using Lattice-Boltzmann Method for two operating point with different rotation speeds are compared to the experimental heat transfer coefficients at the wall. The simulation results show the characteristic flow structures and behavior induced by the different regimes. A sensitivity analysis of the results is presented, both for numerical parameters such as grid resolution and for physical parameters, namely the throughflow velocity profile and shroud temperature.

Numerical analysis of free convection and entropy generation in a cavity using compact finite-difference lattice Boltzmann method

2019 ◽  
Vol 30 (2) ◽  
pp. 977-995 ◽  
Author(s):  
HamidReza KhakRah ◽  
Payam Hooshmand ◽  
David Ross ◽  
Meysam Jamshidian
Keyword(s):  
Heat Transfer ◽  
Rayleigh Number ◽  
Finite Difference ◽  
Free Convection ◽  
Lattice Boltzmann Method ◽  
Entropy Generation ◽  
Lattice Boltzmann ◽  
Content Type ◽  
Flow And Heat Transfer ◽  
Boltzmann Method

Purpose The purpose of this paper is to investigate the compact finite-difference lattice Boltzmann method is used to simulate the free convection within a cavity. Design/methodology/approach The finite-difference discretization method enables the numerical simulations to be run when there are non-uniform and curvilinear grids with a finer near-wall grid resolution. Furthermore, the high-order method is applied in the numerical approach, which makes it possible to go with relatively coarse mesh in respect to simulations, which used classical lattice Boltzmann method. The configuration of the cavity is set to sine-walled square. In addition, the cavity is filled with Al2O3-water nanofluid, and the Koo–Kleinstreuer–Li model is used to estimate the properties of nanofluid. Findings The nanoparticle (Al2O3) concentration in the base fluid (water) is considered in a range of 0-0.04. The nanofluid flow and heat transfer are investigated in laminar regime with Rayleigh number in the range of 103-106. The second law analysis is used to study the effects of different governing parameters on the local and volumetric entropy generation. The Rayleigh number, configuration of the cavity and nanoparticle concentration are considered as the governing parameters. The results are mainly focused on the flow structure, temperature field, local and volumetric entropy generation and heat transfer performance. Originality/value The originality of this study is using of a modern numerical method supported by an accurate prediction for nanofluid properties to simulate the flow and heat transfer during natural convection in a cavity.

Sign in / Sign up

Export Citation Format

Share Document