Simulation of Heat Transfer With LBM and Lagrangian Methods for Microfluidic Applications

2005 ◽  
Author(s):  
Nishitha Thummala ◽  
Dimitrios V. Papavassiliou
Keyword(s):  
Heat Transfer ◽  
Flow Field ◽  
Lattice Boltzmann ◽  
Constant Heat Flux ◽  
Fully Developed Flow ◽  
Thermal Boundary Conditions ◽  
Lattice Boltzmann Simulation ◽  
Lagrangian Tracking ◽  
Boltzmann Method ◽  
Single Flow

This work presents a Lagrangian approach to simulate convective heat transfer in small scales. The fully developed flow field, simulated by a Lattice Boltzmann Method, is combined with Lagrangian tracking of thermal markers to determine the behavior of an instantaneous scalar line source located at the wall of a channel. The resulting probability density functions are used to calculate the behavior of continuous line sources of heat at the wall of the channel, as well as the temperature for the case of constant temperature or constant heat flux from the wall. This method is resourceful in terms of computational efficiency, in that it can be used to simulate various thermal boundary conditions and Prandtl number fluids with a single flow field resulting from a Lattice Boltzmann simulation.

Lattice Boltzmann Simulation of Flow and Heat Transfer Characteristics in a Symmetrically Bifurcated Microchannel

2004 ◽  
Author(s):  
Keqiang Xing ◽  
Yong Tao
Keyword(s):  
Heat Transfer ◽  
Lattice Boltzmann ◽  
Constant Heat Flux ◽  
Lattice Boltzmann Model ◽  
Straight Tube ◽  
Lattice Boltzmann Simulation ◽  
Flux Boundary Conditions ◽  
Boltzmann Method ◽  
Thermal Lattice Boltzmann ◽  
Transfer Problems

The lattice Boltzmann method (LBM) as a relatively new numerical scheme has recently achieved considerable success in simulating fluid flows and associated transport phenomena. However, application of this method to heat transfer problems has been at a stage of infancy. In this work, a thermal lattice Boltzmann model is employed to simulate a two-dimensional, steady flow in a symmetric bifurcation under constant temperature and constant heat flux boundary conditions. The bifurcation effects on the heat transfer and fluid flow are investigated and comparisons are made with the straight tube. Also, different bifurcation angles are simulated and the results are compared with the work of the other researchers.

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.

scholarly journals Heat transfer enhancement inside channel by using the Lattice Boltzmann Method

2020 ◽  
pp. 96-96
Author(s):  
Abchouyeh Asadi ◽  
Ganaoui El ◽  
Rasul Mohebbi ◽  
Mohammad Zarrabi ◽  
Omid Fard ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Fluid Flow ◽  
Flow Field ◽  
Lattice Boltzmann Method ◽  
Forced Convection ◽  
Lattice Boltzmann ◽  
Volume Fraction ◽  
Hybrid Nanofluid ◽  
Boltzmann Method

In this study, the Lattice Boltzmann Method (LBM) is employed in order to examine the fluid flow and forced convection heat transfer inside a two-dimensional horizontal channel with and without obstacles. In order to enhance the heat and thermal energy transfer within the channel, different obstacle arrangements are posed to the flow field and heat transfer with the purpose of studying their sensitivity to these changes. The results indicate that, when the value of the Reynolds number is maximum, the maximum average Nusselt numbers happens on the lower wall (Case 4). The paper extends the topic to the use of nanofluids to introduce a possibility to enhancement of the heat transfer in the channel with an array of the obstacles with forced convection. For this purpose, the AgMgO/water micropolar hybrid nanofluid is used, and the volume fraction of the nanoparticle (50% Ag and 50% MgO by volume) is set between 0 and 0.02. The results showed that, when the hybrid nanofluid is used instead of a typical nanofluid, the rate of the heat transfer inside the channel increases, especially for the high values of the Reynolds number, and the volume fraction of the nanoparticles. Increasing the volume fraction of the nanoparticles increase the local Nusselt number ( 1.17-fold). It is shown that the type of obstacle arrangement and the specific nanofluid can exerts significant effects on the characteristics of the flow field and heat transfer in the channel. This study provides a platform for using the LBM to examine fluid flow through discrete obstacles in offset positions.

Lattice Boltzmann Simulation on Natural Convection Heat Transfer for Phase-Change with Heterogeneously Porous Medium

2011 ◽  
Vol 322 ◽  
pp. 61-67 ◽  
Author(s):  
Jiu Gu Shao ◽  
Yang Liu ◽  
You Sheng Xu
Keyword(s):  
Heat Transfer ◽  
Porous Medium ◽  
Natural Convection ◽  
Phase Change ◽  
Lattice Boltzmann ◽  
Convection Heat Transfer ◽  
Natural Convection Heat Transfer ◽  
Convection Heat ◽  
Lattice Boltzmann Simulation ◽  
Boltzmann Method

The problem of the natural convection heat transfer for phase-change in a square filled with heterogeneously porous medium is solved by lattice Boltzmann method. The lattice Boltzmann equation is governed by the heat conduction equation combined with enthalpy formation. The velocity of liquid part is fully coupled with the temperature distribution through relaxation time. It is found that the high Ra number has significantly impact on the heat transfer and convection, but the low Ra number has little influence on the natural convection. The porosity of the middle porous medium is nothing to do with the heat transfer and convection. The result is of great importance to engineering interest and also provides a new solution to phase transition.

Lattice Boltzmann Simulation of Flow and Heat Transfer Characteristics in a Symmetric Bifurcation

2005 ◽  
Author(s):  
K. Q. Xing ◽  
Y.-X. Tao
Keyword(s):  
Heat Transfer ◽  
Lattice Boltzmann ◽  
Passive Scalar ◽  
Heat Fluxes ◽  
Lattice Boltzmann Model ◽  
Lattice Boltzmann Simulation ◽  
Flux Boundary Conditions ◽  
Constant Wall Heat Flux ◽  
Boltzmann Method ◽  
Thermal Lattice Boltzmann

The lattice Boltzmann method (LBM) originates from the discrete kinetic theory and has been applied for simulation of various kinds of fluid flows under different conditions. In this paper, a passive-scalar-based thermal lattice Boltzmann model is employed to simulate the steady flow in a symmetric bifurcation channel under constant wall heat flux boundary conditions. The bifurcation effects on the heat transfer and fluid flow are thoroughly investigated under different Reynolds numbers, wall heat fluxes and bifurcation angles. The results are compared with the commercial software output. A useful discussion about how to transfer from lattice units to actual physical units is also presented.

scholarly journals Lattice Boltzmann simulation of Rayleigh-Benard convection in enclosures filled with Al2O3-water nanofluid

2018 ◽  
Vol 22 (Suppl. 2) ◽  
pp. 535-545
Author(s):  
Weihua Cai ◽  
Zhifeng Zheng ◽  
Changye Huang ◽  
Yue Wang ◽  
Xin Zheng ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Lattice Boltzmann ◽  
Convection Heat Transfer ◽  
Bénard Convection ◽  
Lattice Boltzmann Simulation ◽  
Benard Convection ◽  
Wide Range ◽  
Boltzmann Method ◽  
Rayleigh Benard Convection ◽  
Rayleigh Benard

In order to clarify the controversies for the role of nanoparticles on heat transfer in natural convection, lattice Boltzmann method is used to investigate Rayleigh-Benard convection heat transfer in differentially-heated enclosures filled with Al2O3-water nanofluids. The results for streamline and isotherm contours, vertical velocity, and temperature profiles as well as the local and average Nusselt number are discussed for a wide range of Rayleigh numbers and nanoparticle volume fractions (0 ? ? ? 5%). The results show that with the increase of Rayleigh number and nanoparticles loading, Nuave increases. It is suggested that the addition of nanoparticles can enhance the heat transfer in Rayleigh-Benard convection.

LATTICE BOLTZMANN SIMULATION ON NATURAL CONVECTION HEAT TRANSFER IN A TWO-DIMENSIONAL CAVITY FILLED WITH HETEROGENEOUSLY POROUS MEDIUM

2006 ◽  
Vol 17 (06) ◽  
pp. 771-783 ◽  
Author(s):  
WEI-WEI YAN ◽  
YANG LIU ◽  
ZHAO-LI GUO ◽  
YOU-SHENG XU
Keyword(s):  
Heat Transfer ◽  
Porous Medium ◽  
Natural Convection ◽  
Lattice Boltzmann ◽  
Fluid Velocity ◽  
Convection Heat Transfer ◽  
Published Data ◽  
Lattice Boltzmann Simulation ◽  
Natural Convection Problem ◽  
Boltzmann Method

The natural convection problem in a square cavity filled with heterogeneously porous medium is solved by lattice Boltzmann method. The temperature distribution is fully coupled with the fluid velocity through relaxation time. The present calculated results are in good agreement with available published data. It is found that the porosity of porous media near the walls has significant influence on the heat transfer, and the porosity of middle porous medium has little influence on the natural convection. It is of particular interest for thermal management in electronic packages, since it can reduce the space of air.

Lattice Boltzmann simulation of fluid flow and heat transfer in a parallel-plate channel with transverse rectangular cavities

2017 ◽  
Vol 28 (03) ◽  
pp. 1750042 ◽  
Author(s):  
Rasul Mohebbi ◽  
Hanif Heidari
Keyword(s):  
Heat Transfer ◽  
Aspect Ratio ◽  
Lattice Boltzmann ◽  
Convection Heat Transfer ◽  
Numerical Code ◽  
Nusselt Numbers ◽  
Flow And Heat Transfer ◽  
Lattice Boltzmann Simulation ◽  
Smooth Channel ◽  
Boltzmann Method

The aim of this paper is investigating the forced convection heat transfer in a channel with transverse rectangular cavities using the lattice Boltzmann method (LBM) which is not available in the literature yet. The effects of the Reynolds number (100–400), cavity aspect ratio ([Formula: see text], 0.5, 1.0), distance of cavities from each other ([Formula: see text]) in fixed depth of cavity ([Formula: see text]) on the velocity and temperature profiles are studied. Moreover, the flow patterns such as deflection and re-circulation zone inside the cavities are obtained. The local and averaged Nusselt numbers on the channel walls are achieved. The results show that the channel with cavities achieves heat transfer enhancements relative to the smooth channel. For the constant cavity aspect ratio, the maximum value of averaged Nusselt number in the channel is obtained in the case of [Formula: see text]. Heat transfer to the working fluids increases significantly by increasing the aspect ratio. The existed results are used to ascertain the validity of the numerical code and excellent agreement between results was found.

scholarly journals Lattice Boltzmann Simulation of Airflow and Mixed Convection in a General Ward of Hospital

2016 ◽  
Vol 2016 ◽  
pp. 1-15 ◽  
Author(s):  
Taasnim Ahmed Himika ◽  
Md. Farhad Hasan ◽  
Md. Mamun Molla
Keyword(s):  
Heat Transfer ◽  
Mixed Convection ◽  
Lattice Boltzmann ◽  
Average Rate ◽  
Reynolds Numbers ◽  
General Ward ◽  
Convection Flow ◽  
Indoor Airflow ◽  
Lattice Boltzmann Simulation ◽  
Boltzmann Method

In the present investigation the airflow and heat transfer for mixed convection have been simulated for a model general ward of hospital with six beds and partitions using the Lattice Boltzmann Method (LBM). Three different Reynolds numbers 100, 250, and 350 have been considered. Bounce-back condition has been applied at the wall. Results have been represented in three different case studies and the changes have been discussed in terms of streamlines and isotherms. Code validation has also been included before going through the simulation process and it shows good agreement with previously published papers when the comparison is made on average Nusselt number. Results show that the pattern of indoor airflow is varied in each and every case study due to the effect of mixed convection flow and placement of partition. In addition, the changes in average rate of heat transfer indicate that patients closer to inlet get the most air and feel better and if any patient does not need much air, he or she should be kept near the outlet to avoid temperature related complications.

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