scholarly journals Direct numerical simulation of the sedimentation of solid particles with thermal convection

2003 ◽  
Vol 481 ◽  
pp. 385-411 ◽  
Author(s):  
HUI GAN ◽  
JIANZHONG CHANG ◽  
JAMES J. FENG ◽  
HOWARD H. HU
Keyword(s):  
Numerical Simulation ◽  
Direct Numerical Simulation ◽  
Thermal Convection ◽  
Solid Particles

scholarly journals DIRECT NUMERICAL SIMULATION OF PARTICLE SEDIMENTATION IN TWO-PHASE FLOW UNDER THERMAL CONVECTION

2011 ◽  
Vol 08 (04) ◽  
pp. 851-861 ◽  
Author(s):  
J. Z. CHANG ◽  
H. T. LIU ◽  
T. X. SU ◽  
M. B. LIU
Keyword(s):  
Numerical Simulation ◽  
Direct Numerical Simulation ◽  
Thermal Convection ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Particle Sedimentation ◽  
Two Phase ◽  
Elliptical Particles ◽  
Particle Shapes ◽  
Sedimentation Processes

This paper presents a direct numerical simulation of particle sedimentation in two-phase flow with thermal convection. The sedimentation processes of elliptical particles are investigated in three different scenarios with isotherm, hot, and cold Newtonian fluids. We demonstrate that different particle shapes and orientations can result in quite different flow behaviors. Some interesting results have been obtained, which are very helpful for better understanding of the particle sedimentation processes.

scholarly journals Direct numerical simulation of the sedimentation of two particles with thermal convection

2010 ◽  
Vol 59 (3) ◽  
pp. 1877
Author(s):  
Liu Han-Tao ◽  
Chang Jian-Zhong ◽  
An Kang ◽  
Su Tie-Xiong
Keyword(s):  
Numerical Simulation ◽  
Direct Numerical Simulation ◽  
Thermal Convection

scholarly journals Direct Numerical Simulation of Turbulent Flows Laden with Droplets or Bubbles

2019 ◽  
Vol 51 (1) ◽  
pp. 217-244 ◽  
Author(s):  
Said Elghobashi
Keyword(s):  
Numerical Simulation ◽  
Numerical Methods ◽  
Direct Numerical Simulation ◽  
Turbulent Flows ◽  
Surface Deformation ◽  
Direct Numerical Simulations ◽  
Solid Particles ◽  
Length Scale ◽  
Single Droplet ◽  
Kolmogorov Length Scale

This review focuses on direct numerical simulations (DNS) of turbulent flows laden with droplets or bubbles. DNS of these flows are more challenging than those of flows laden with solid particles due to the surface deformation in the former. The numerical methods discussed are classified by whether the initial diameter of the bubble/droplet is smaller or larger than the Kolmogorov length scale and whether the instantaneous surface deformation is fully resolved or obtained via a phenomenological model. Also discussed are numerical methods that account for the breakup of a single droplet or bubble, as well as multiple droplets or bubbles in canonical turbulent flows.

Direct Numerical Simulation of the Motion of Particles Larger Than the Kolmogorov Scale in a Homogeneous Isotropic Turbulence

2008 ◽  
Author(s):  
Cedric Corre ◽  
Jean-Luc Estivalezes ◽  
Stephane Vincent ◽  
Olivier Simonin
Keyword(s):  
Numerical Simulation ◽  
Direct Numerical Simulation ◽  
Isotropic Turbulence ◽  
Industrial Applications ◽  
Point Particle ◽  
Solid Particles ◽  
Physical Forcing ◽  
Kolmogorov Length Scale ◽  
Free Case ◽  
Grid Points

Predicting interactions between particles and a surrounding viscous fluid is the concern of many environmental and industrial applications. A Direct Numerical Simulation (DNS) of dilute isotropic turbulent particulate flow has been conducted in a periodic box, with 1283 grid points. The objective is to understand the modification of isotropic turbulence due to dispersed solid particles by analyzing the DNS results. Previous numerical simulations have been, for the most part, limited to the point-particle regime. On the opposite, in these simulations, the diameter of the particles is larger than the Kolmogorov length scale. In order to maintain a constant turbulent kinetic energy, a physical forcing scheme is implemented. Thereby, statistics on the characteristics of the particles are more reliable. Furthermore, interactions between particles are treated via a repulsing force, consequently, simulations are four-way coupling. Simulations are performed with a fictitious domain approach and with the penalty method. For solving the velocity-pressure coupling, an augmented Lagrangian optimization algorithm is used. Results present the influence of the particle phase on the turbulence spectrum. Moreover, the comparison with particle-free case is particularly interesting notably about the anisotropy of the flow caused by the presence of the particles.

Application of the Immersed Boundary Method and Direct Numerical Simulation for the Heat Transfer From Particles

2009 ◽  
Author(s):  
Zhi-Gang Feng ◽  
Efstathios E. Michaelides
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Direct Numerical Simulation ◽  
Density Function ◽  
Fluid Phase ◽  
Solid Particles ◽  
Computational Method ◽  
Immersed Boundary ◽  
Force Density ◽  
Particulate Flows

A combination of the Direct Numerical Simulation (DNS) with the Immersed Boundary (IB) method has been developed to solve the momentum and heat transfer equations for the computation of thermal convection in particulate flows. This numerical method makes use of a finite difference method in and uses a regular Eulerian grid to solve the modified momentum and energy equations for the entire flow region simultaneously. In the region that is occupied by the solid particles, a second particle-based Lagrangian grid is used, which tracks all the particles, and a force density function or an energy density function is introduced to represent the momentum interaction or thermal interaction between the particulate phase and fluid phase. The numerical methods presented have been validated by comparing the results of the simulation with similar numerical results obtained by others. Among the advantages of this computational method is that it may be used for the determination, stipulation and validation of boundary conditions in particulate flows that may be used with larger Eulerian codes.

Sign in / Sign up

Export Citation Format

Share Document