scholarly journals Investigation of particle deposition and dispersion using Hybrid LES/RANS model based on Lattice Boltzmann method

2018 ◽  
Vol 0 (0) ◽  
pp. 0-0
Author(s):  
H. Sajjadi ◽  
M. Salmanzadeh ◽  
G. Ahmadi ◽  
S. Jafari
Keyword(s):  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Particle Deposition ◽  
Rans Model ◽  
Model Based ◽  
Boltzmann Method

scholarly journals Development of hybrid model based on Lattice Boltzmann Method and Cellular Automata devoted for phase transformation – simulation of heat flow with consideration of enthalpy

2018 ◽  
Vol 240 ◽  
pp. 01020
Author(s):  
Łukasz Łach ◽  
Robert Straka ◽  
Dmytro Svyetlichnyy
Keyword(s):  
Heat Transfer ◽  
Phase Transformation ◽  
Heat Flow ◽  
Lattice Boltzmann Method ◽  
Hybrid Model ◽  
Lattice Boltzmann ◽  
Model Based ◽  
Diffusion Phase ◽  
Boltzmann Method ◽  
New Phase

In heat treatment of materials, the phase transformation is an important phenomenon, which determines the final microstructure. The microstructure of different materials described by such parameters as morphology, grain size, phase fraction and their spatial distribution, largely effects on the mechanical and functional properties of final products. The subject of the work is a development of a hybrid model based on CA and Lattice Boltzmann method (LBM) for modeling of the diffusion phase transformation. The model has a modular structure and simulates three basic phenomena: diffusion, heat flow and phase transformation. The objective of the paper is a presentation of module of the hybrid model for simulation of heat flow with considering of enthalpy of transformation. This is one of the stages in the development of the model and obtained results will be used in a combined solution of heat transfer and diffusion during the modeling of diffusion phase transformations. Lately, the model will be extended to three dimensions and will use hybrid computational systems (CPU and GPU). CA and LBM are used in the model as follows. LBM is used for modeling of heat flow, while CA is used for modeling of microstructure evolution during the phase transformation. The main factors considered in the model are the enthalpy of transformation and heat transfer. The paper presents the results of the modeling of the new phase growth determined by different values of overcooling affecting on different values in the enthalpy of transformation. The heat flow is simulated and the results for some modeling variants are shown. Examples of simulation results obtained from the modeling are presented in the form of images, which present the growth of new phase and temperature distributions.

Lattice Boltzmann Method Simulation of Turbulent Indoor Airflow Using Hybrid LES/RANS Model

2017 ◽  
Author(s):  
H. Sajjadi ◽  
M. Salmanzadeh ◽  
G. Ahmadi ◽  
S. Jafari
Keyword(s):  
Lattice Boltzmann Method ◽  
Hybrid Model ◽  
Turbulence Model ◽  
Lattice Boltzmann ◽  
Large Scale ◽  
Computational Time ◽  
Wall Region ◽  
Rans Model ◽  
Boltzmann Method ◽  
Near Wall

In this study the hybrid RANS/LES turbulence model within the framework of the Lattice Boltzmann method (LBM) was used to study turbulent indoor airflows. In this approach the near wall region was simulated by the RANS model, while the bulk of the domain was analyzed using the LES model with the LBM approach. In the near wall layer where RANS was used, the k-ε turbulence model was employed. For the k-ε turbulence model in conjunction with the LBM two population balance equations for k and ε were used. The present simulation results for the airflow showed good agreement with the experimental data and the earlier numerical results for the hybrid RANS/LES. The results showed that the hybrid model properly predicted the large scale turbulence fluctuation velocities in the bulk of the flow region. In addition, the computational time for the hybrid model is less than that of the LES method.

Numerical Study of Angle of Incidence Effect on Particle Deposition Over a Square Cylinder in a Channel Using Lattice-Boltzmann Method

2009 ◽  
Author(s):  
S. Jafari ◽  
M. Salmanzadeh ◽  
M. Rahnama ◽  
G. Ahmadi
Keyword(s):  
Computational Model ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Particle Deposition ◽  
Numerical Study ◽  
Particle Dispersion ◽  
Solid Particles ◽  
Angle Of Incidence ◽  
Square Cylinder ◽  
Boltzmann Method

Particle dispersion and deposition over a square cylinder with different angles of incidence (α = 0°, 45°) in a channel flow was investigated numerically. A computational model using Lattice-Boltzmann Method (LBM) for flow simulation was developed. The interpolated bounce-back (IBB) boundary condition was applied to model the no-slip boundary conditions on curved boundary. The computational model was used to simulate the two-dimensional airflow field in the duct with obstructing square cylinder. A Lagrangian approach was used for simulation of spherical, solid particles suspended in the airflow in the duct. The Reynolds numbers were in the range of laminar. The formation of the von Karman vortex sheet behind the cylinder was predicted by the present LBM simulation. It was shown that the periodicity of the simulated vortex street agrees well with available experimental data. Transport and deposition of 1 μm to 100 μm particles in the duct were studied. The instantaneous flow field was used to evaluate the particle trajectories. The forces included in the particle equation of motion were drag, lift, gravity, and Brownian. The simulation results shows that the particle deposition efficiency decreases when the angle of incidence is increased from 0° to 45° and also more vigorous vortex shedding was observed at α = 45°.

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