MHD free convection heat transfer of a water–Fe3O4 nanofluid in a baffled C-shaped enclosure

Journal of Thermal Analysis and Calorimetry - In this paper, the effect of a baffle on free convection heat transfer of a water–Fe3O4 nanofluid in a C-shaped enclosure in the presence of a...     

Numerical investigation of mixed convection heat transfer of a nanofluid in a circular enclosure with a rotating inner cylinder

Journal of Thermal Analysis and Calorimetry - In the present paper, mixed convection heat transfer of water–Al2O3 nanofluid in the space between two cylinders is investigated numerically. The...     

Investigation of MHD effect on nanofluid heat transfer in microchannels

Journal of Thermal Analysis and Calorimetry - An incompressible preconditioned lattice Boltzmann method (IPLBM) is proposed to investigate the fluid flow and heat transfer characteristics of...     

Numerical investigation of various nanofluid heat transfers in microchannel under the effect of partial magnetic field: lattice Boltzmann approach

Journal of Thermal Analysis and Calorimetry - In the present paper, the effect of the external partial magnetic field is studied on the flow and heat transfer of various nanofluids in a...     

Numerical investigation of mixed convection heat transfer behavior of nanofluid in a cavity with different heat transfer areas

Journal of Thermal Analysis and Calorimetry - The main purpose of this research is the numerical modeling of laminar mixed convection heat transfer inside an open square cavity with different heat...     

The effects of L-shaped heat source in a quarter-tube enclosure filled with MHD nanofluid on heat transfer and irreversibilities,using LBM: numerical data,optimization using neural network algorithm (ANN)

Journal of Thermal Analysis and Calorimetry - In this paper, the process of natural convection heat transfer (NCHT) and production of entropy (POF) in a portion of a tube has been modeled...     

Investigation of nanofluids on heat transfer enhancement in a louvered microchannel with lattice Boltzmann method

Numerical studies of laminar forced convective heat transfer and fluid flow in a 2D louvered microchannel with Al₂O₃/water nanofluids are performed by the lattice Boltzmann method (LBM). Eight louvers are arranged in tandem within the single-pass microchannel. The Reynolds number based on channel hydraulic diameter and bulk mean velocity ranges from 100 to 400, where the Al₂O₃ fraction varies from 0 to 4%. A double distribution function approach is adopted for modeling fluid flow and heat transfer. Code validations are performed by comparing the streamwise Nusselt number (Nu) profiles and Fanning friction factors of the present LBM and those of the analytical solutions. Good agreements are obtained. Simulated results show that the louver microstructure can disturb the core flow and guide coolant toward the heated walls, thus enhancing the heat transfer significantly. Furthermore, the addition of nanoparticles in microchannels can also augment the heat transfer, but it creates an unnoticeable pressure loss. With both the louver microstructure and nanofluid, a maximum overall Nu enhancement of 7.06 is found relative to that of the fully developed smooth channel.

     

Using artificial neural network to optimize the flow and natural heat transfer of a magnetic nanofluid in a square enclosure with a fin on its vertical wall: a lattice Boltzmann simulation

Journal of Thermal Analysis and Calorimetry - The heat transfer of a nanofluid in a square enclosure is numerically simulated using FORTRAN software in this paper, by considering the radiation...     

格子Boltzman方法数值模拟微通道内不互溶液液两相流动

利用基于场介子格子Boltzman(LB)方法对T形微通道内油-水不互溶两相流动进行了数值模拟.通过静止液滴算例改进该两相流LB模型且验证了模型的有效性,成功数值模拟了T形微通道内油水两相流的五种不同流型.数值模拟结果和实验数据定性和定量吻合很好,表明本文数值方法的有效性.此外,采用改进后的LB两相流模型模拟了不同界面张力和接触角条件下的液滴形成过程,讨论了这两个变量对流型和液滴形状的影响.结果表明LB方法是研究微通道内不互溶两相流的一种有效的数值工具,能够对各种涉及不互溶多相流微流体设备的设计提供指导.     

Numerical simulation of immiscible liquid-liquid flow in microchannels using lattice Boltzmann method

Immiscible kerosene-water two-phase flows in microchannels connected by a T-junction were numerically studied by a Lattice Boltzmann (LB) method based on field mediators.The two-phase flow lattice Boltzmann model was first validated and improved by several test cases of a still droplet.The five distinct flow regimes of the kerosene-water system,previously identified in the experiments from Zhao et al.,were reproduced.The quantitative and qualitative agreement between the simulations and the experimental dat...     

Mixed convection heat transfer of a nanofluid in a lid-driven enclosure with two adherent porous blocks

Journal of Thermal Analysis and Calorimetry - Convective flow and heat transfer in an alumina/water nanofluid enclosure having two centered adherent porous blocks under the effect of moving upper...     

Numerical simulation of a three-layer porous heat exchanger considering lattice Boltzmann method simulation of fluid flow

Journal of Thermal Analysis and Calorimetry - The present study investigates the thermal characteristics of a proposed porous heat exchanger (PHE). This heat exchanger consists of three sections,...     

A study on the effect of magnetic field and the sinusoidal boundary condition on free convective heat transfer of non-Newtonian power-law fluid in a square enclosure with two constant-temperature obstacles using lattice Boltzmann method

Journal of Thermal Analysis and Calorimetry - In this paper, the flow pattern and thermal characteristics of free convection of a Newtonian magnetohydrodynamic fluid flow inside a square enclosure...     

LBM simulation of MHD nanofluid heat transfer in a square cavity with a cooled porous obstacle: effects of various temperature boundary conditions

Journal of Thermal Analysis and Calorimetry - Nanofluid natural convection inside a cavity with a porous square obstacle in the presence of magnetic field is simulated by lattice Boltzmann method....     

Numerical study of heat transfer enhancement from a heated circular cylinder by using nanofluid and transverse oscillation

Journal of Thermal Analysis and Calorimetry - Adding nanoparticles into the base fluid and oscillating the target surface are two passive and active techniques, respectively, for heat transfer...     

Numerical investigation of liquid water transport and distribution in porous gas diffusion layer of a proton exchange membrane fuel cell using lattice Boltzmann method

Lattice Boltzmann method (LBM) is used to investigate liquid water transport and distribution in a porous gas diffusion layer (GDL). The GDL with microscopic porous structures is obtained from three-dimensional reconstruction using the stochastic method, and its macroscopic transport properties including permeability and effective diffusivity are numerically predicted which agree well with the existing experimental results. Simulation results show that liquid water transport mechanism in the GDL is capillary fingering and liquid water pathway is interconnected, which confirms the previous experimental results in literature. Further, effects of GC wettability are explored and it is found out that a hydrophilic GC leads to less liquid water accumulated in the GDL compared with a hydrophobic GC. In addition, effects of GDL wettability on liquid water distribution are explored. Simulation results show that PTFE content itself cannot determine liquid water distribution inside the GDL and detailed distributions of hydrophobic and hydrophilic regions within the GDL also play an import role. Moreover, a hydrophilic GDL is more beneficial for reactant transport than a hydrophobic GDL if liquid water presents as separated droplets or films in the GDL.     

Numerical investigation on the effect of magnetic field on natural convection heat transfer from a pair of embedded cylinders within a porous enclosure

The present work examines the influence of magnetohydrodynamic field on natural convection phenomena inside a porous square enclosure with a pair of embedded hot circular cylinders. Numerical investigations are performed to understand the effects of interspacing distance between the embedded cylinders, Hartmann number, Rayleigh number and Darcy number on the thermal transport process and the total irreversibility generation. It is observed that the isotherm distribution is strongly affected by the presence of magnetic field although the distribution of streamlines remains independent of the strength of magnetic field. This underlines the fact that magnetic field strongly influences the heat transfer process and entropy generation characteristics. It reveals that the natural convection is suppressed in the presence of a higher magnetic field as evident from the reduction in Nusselt number. It is observed that an increase in the spacing between the cylinders increases the heat transfer rate, and moreover, the effect of the magnetic field on heat transfer is more pronounced at higher interspacing distance between the embedded cylinders. The heat transfer rate increases significantly with the increase in the permeability of the medium. The entropy generation rate is independent of the strength of applied magnetic field. Further, the contribution of the entropy generation owing to friction is found to be negligible in total irreversibility obtained at lower values of Rayleigh number irrespective of Darcy number. However, the contribution of irreversibility owing to heat transfer is found to be minimal at higher values of Rayleigh number.

     

Experimental investigation of natural convection heat transfer characteristics in MWCNT-thermal oil nanofluid

Journal of Thermal Analysis and Calorimetry - The carbon nanotubes are considered as one of the highest thermal conductive material which is having a variety of heat transfer applications. The...     

MHD heat and mass transfer stagnation point nanofluid flow along a stretching sheet influenced by thermal radiation

Journal of Thermal Analysis and Calorimetry - The objective of the present study seems to be to explore the numerical findings of the steady incompressible 2-D MHD stagnation point flow of...