Two-sided Lid-driven Cavity Research Articles

The role of permeability in lid-driven cavity flow containing a cluster of hot solids

The flow behavior of particle clusters with thermal convection in confined fluid flow has garnered considerable attention. One of the remaining challenges is to understand the role of a porous structure of particle clusters in the confined thermal fluid flow. In present work, a numerical study based on a double distribution function lattice Boltzmann model has been conducted to unveil the two-sided lid-driven cavity flow containing a hot cluster formed by an array of center-placed solids. First, we investigated the heat transfer by varying the Richardson number (Ri, from 0.01 to 1.0) and the solid fraction of the cluster (ϕ, from 0.0143 to 0.6734) with fixed cavity Reynolds number (Re=1000) and Prandtl number (Pr=0.7). The increase in Ri would lead to the formation of non-centrosymmetric streamlines and isotherms and an increase in the total averaged Nusselt number Nu¯a, in which several vortex structures being identified at high Ri and ϕ. Then, we explored the influence of permeability, quantified by the Darcy number (Da), by changing the porous structure of cluster via rearranging the array of solids. It is found that a higher permeability could enhance heat transfer of particle cluster due to the increase in convection, but the smaller surface area of solid particles would limit heat transfer. A correlation of Nu¯a with respect to Ri and Da could be developed based on our two-dimensional simulation results, allowing the evaluation of involved interplay between the porous structure of particle cluster and thermal convection in confined flow via a simple yet effective way.

Motion of a two-dimensional neutrally buoyant circular particle in two-sided lid-driven cavity flow with thermal convection

Understanding the interaction between a cold particle and confined fluid flow is of practical importance in many industrial applications. In this work, the motion of a two-dimensional circular neutrally buoyant particle in thermal flows in the two-sided lid-driven cavity has been numerically investigated by the lattice Boltzmann model with immersed boundary method. We examined the effects of Grashof number (Gr) and Reynolds number (Re) of cavity on the motion of particle in the range of 104 ≤ Gr ≤ 107 and 500 ≤ Re ≤ 3000. It is found that the motion of the cold particle in the cavity flow manifests four different modes, driven by the competition between buoyancy-driven natural convection and lid-driven forced convection. With the increase in Gr or the decrease in Re, the motion of the cold particle would evolve from modes I to IV. We further obtained the diagram of motion modes of the cold particle with regard to Gr and Re. And a power law correlation that relates the critical Gr to Re of the cavity is proposed and capable of well predicting the transition of particle motion modes.

Study of unsteady non-Newtonian fluid flow behavior in a two-sided lid-driven cavity at different aspect ratios

Study of unsteady non-Newtonian fluid flow behavior in a two-sided lid-driven cavity at different aspect ratios

Numerical investigation of flow structures in multi-sided lid-driven cubic cavities with various ratios by MRT-LBE

In this study, three-dimensional (3D) numerical simulations are carried on water flow in multi-sided lid-driven cubic cavities to investigate the flow structures by using multiple relaxation time (MRT) lattice Boltzmann equation (LBE), in which fifteen velocity directions model (D3Q15) is employed and the corresponding boundary conditions are derived. Comparisons among numerical results of the MRT-LBE, other references and ANSYS-FLUENT, indicate that the MRT-LBE is competent for simulation of flow field in cubic cavity with high Reynolds number. Therefore, 3D numerical simulations of eight different cases are performed for the flow in single-side lid-driven cavities with various ratios of width to height under different Reynolds numbers by using MRT-LBE. Furthermore, MRT-LBE is also applied to simulate the flow in multi-sided lid-driven cubic cavities under eight different cases. It can be concluded from the simulated results that the main vortex moves towards to the center of the cavity as the ratio of width to height or the Reynolds number increasing for single-side lid-driven cavities. The flow structures in cavities with single-sided driven and multi-sided driven are quite different. In two-sided lid-driven cubic cavity, the flow structure is symmetrical about the horizontal section Z=H/2 or principle diagonal line (Z=X), In the four-sided driven cubic cavity, the flow structure is symmetric about two diagonal sections (Z=X and Z=−X).

On the Analysis of Thermosolutal Mixed Convection with Soret and Dufour Effects in a Two-Sided Lid-Driven Deep Cavity

On the Analysis of Thermosolutal Mixed Convection with Soret and Dufour Effects in a Two-Sided Lid-Driven Deep Cavity

Combined effects of velocity ratio and radii sizes of internal cylinder on the flow instability in a two-sided lid-driven cubical cavity

This paper computes the laminar flow in a three-dimensional (2D) two-sided lid-driven cubical cavity induced by a centrally located circular cylinder by Finite Volume Method and multigrid acceleration. The cavity has left and right parallel lid-driven walls and all the other walls completing the domain are motionless. Furthermore, different wake parameters are considered throughout this study; velocity ratios [[Formula: see text] and 0.75] and radius size of the inner cylinder [[Formula: see text] and 0.2]. Thereafter, the study has been extended to the unsteady state by further increasing Reynolds number till reaching up to 2000. It is noticed that the highest critical Reynolds number corresponds to the lowest radius size and conversely. By further increasing the velocity ratio till reaching 0.25, 0.5 and 0.75, where the left moving lid began to have an effect, the opposite phenomenon occurs and we note that the highest critical Reynolds number corresponds to the highest radius. This can be explained by the fact that when the cavity is two-sided lid-driven, the velocity of the fluid particles accelerates. Besides, it has been proved that both parameters [Formula: see text] and a radius size [Formula: see text] promote faster transition to the unsteadiness rather than the remaining velocity ratios and radii sizes.

Heat and mass transfer in a two-sided lid-driven square cavity with non-uniform sinusoidal heating on horizontal walls

Heat and mass transfer in a two-sided lid-driven square cavity with non-uniform sinusoidal heating on horizontal walls

Mixed Convection in a Two-Sided and Four-Sided Lid-Driven Square Porous Cavity

The present paper investigates the mixed convection in a two-sided and four-sided lid-driven square cavity in porous media. In the two-sided porous cavity, the left and right walls of the enclosure are maintained at constant but different temperatures, while the top and bottom walls are adiabatic. The top and the bottom walls of the enclosure move with a constant speed from left to right. In the four-sided porous cavity, the top and the bottom walls of the enclosure move from left to right and right to left, respectively, while the left and the right walls move from top to bottom and bottom to top, respectively, with a constant speed. The left and right walls of the enclosure are maintained at different heat fluxes, while the top and bottom walls are maintained at hot and cold temperatures, respectively. The governing equations are discretized by the fully implicit finite difference method, namely, Alternating-Direction-Implicit (ADI) method. The numerical results are analyzed for the effect of Darcy number (Da = 0.001, 0.01), Prandtl number (Pr = 7), Grashof number (Gr = 50,000), porosity (ε = 0.2) and viscosity ratio (Λ = 1, 3). The stability and convergence of the considered problem have been proved using the Matrix method.

Mixed convective heat transfer and heat generation simulation in lid-driven enclosure filled with porous medium

Researchers in heat transfer field always attempt to find new solutions to optimize the performance of energy devices through heat transfer enhancement. Among various methods which are implemented to reinforce the thermal performance of energy systems, one is utilizing porous media in heat exchangers. In this study, characteristics of laminar mixed convection in a porous two-sided lid-driven square cavity induced by an internal heat generation at the bottom wall have been carried out by using a numerical methodology based on the finite volume method and the full multigrid acceleration. The two-sided and top walls of the enclosure are assumed to have cold temperature while the remaining walls of the bottom wall are insulated. The working fluid is air so that the Prandtl number equates 0.71. The behavior of different physical parameters is shown graphically so that computations have been conducted over a wide range of pertinent parameters; (10[Formula: see text] Ri [Formula: see text]), Darcy number ([Formula: see text] Da [Formula: see text]), internal Rayleigh number ([Formula: see text] Ra[Formula: see text]), the porosity ([Formula: see text]) and the Grashof number (10[Formula: see text] Gr [Formula: see text]). Results revealed that heat transfer mechanism and the flow characteristics inside the enclosure are strongly dependent on the Grashof number. For instance, the best heat transfer rates at the considered values of internal Rayleigh numbers are obtained for a high Grashof number. Furthermore, an increase of internal heat generation (RaI) leads to a higher flow and temperature intensities for Grashof numbers ranging from [Formula: see text] to [Formula: see text] and a specific Richardson number value. Besides, an increase in porosity values ([Formula: see text]) leads to an obvious decrease in the average Nusselt number. Maximum temperature [Formula: see text] is optimal for high ([Formula: see text]) value. A correlation expression for the average Nusselt number relative to the internal heat source was established in function of two control parameters such as Darcy and Richardson numbers.

Numerical Assessment of Turbulent Flow Driving in a Two-Sided Lid-Driven Cavity with Antiparallel Wall Motion

In this paper, the case of the steady two-dimensional flow in a two-sided lid-driven square cavity is numerically investigated by the finite volume method (FVM). The flow motion is due to the top and bottom horizontal walls sliding symmetrically in the opposite direction with equal velocities, UT and UB, obtained through three respective Reynolds numbers, Re1,2=10000, 15000, and 20000. Due to the lack of availability of experimental results in this Reynolds number margin for this type of flow, the problem is first examined by considering that the flow is turbulent with the inclusion of four commonly used RANS turbulence models: Omega RSM, SST k-ω, RNG k-ε and Spalart-Allmaras (SA). Next, the regime is considered being laminar in the same range of Reynolds numbers. A systematic evaluation of the flow characteristics is performed in terms of stream-function contour, velocity profiles, and secondary vortices depth. Examination of the calculation results reveals the existence of a great similarity of the predicted flow structures between the Omega RSM model and those from the laminar flow assumption. On the other hand, the computed flow with the SST k-ω model, the RNG k-ε model, and the SA model reveals a remarkable under-prediction which appears clearly in the size and number of secondary vortices in the near-wall regions. Various benchmarking results are presented in this study.

Mixed Convection in a Two-Sided Lid-Driven Square Cavity Filled with Different Types of Nanoparticles: A Comparative Study Assuming Nanoparticles with Different Shapes

Mixed Convection in a Two-Sided Lid-Driven Square Cavity Filled with Different Types of Nanoparticles: A Comparative Study Assuming Nanoparticles with Different Shapes

A 3D computational study of flow instability development due to driven cavity with a cylindrical shape at different locations

A numerical investigation has been carried out to study the two-sided lid-driven cubical cavity induced by a cylindrical shape at the centre. This problem is solved by a finite volume method using multigrid acceleration. The cavity has left and right parallel lid-driven walls and all the other walls completing the domain are motionless. Different locations of the inner cylinder along the centreline at left and right parts of the enclosure; [P1(0.3,0.3), P2(0.7,0.3), P3(0.7, 0.7) and P4(0.3, 0.7)] are employed encompassing descriptive Reynolds numbers ranging three orders of magnitude 100, 400 and 1000. The obtained results show that positions P3 and P4 of the inner cylinder promote cell distortion. Thereafter, the study has been extended to the unsteady state by further increasing Reynolds number till reaching 1500. It has been proved that a cylinder centrally located inside the enclosure promotes faster transition to the unsteadiness rather than the four considered locations.

Lattice Boltzmann Simulations of Coupled Mixed Convection and Radiation Effect in a Two-Sided Lid-Driven Enclosure

Using Lattice Boltzmann Method (LBM), the mixed convection and surface radiation effect in a two-sided lid-driven square cavity is studied numerically with air as a working fluid. The numerical code is validated against results available in the literature. The parameters governing the problem are the emissivity of the walls, the Reynolds number and the Richardson number that was varied through the Grashof number. The results obtained show significant effects of the Richardson number and surface radiation on the overall structure of the flow and heat transfer characteristics. The contribution of radiation component to the total Nusselt number outclasses that of convection for high emissive walls at some threshold value of Richardson number.

Numerical simulation of mixed convection in a two-sided lid-driven square cavity with four inner cylinders based on diamond arrays

The hydrodynamics and thermal characteristics due to mixed convection in a vertical two-sided lid-driven differentially square cavity containing four hot cylinders in a diamond array are investigated by the lattice Boltzmann equation model. The moving walls of the cavity are cold while the others are adiabatic. The flow in the cavity is driven by both the temperature difference and the moving vertical walls. The influence of different flow governing parameters, including the direction of the moving walls (the left wall moves up and the right wall moves down (Case I), both the left and right walls are moving upward (Case II), both the left and right walls are moving downwards (Case III)), the distance between neighboring cylinders [Formula: see text] ([Formula: see text]), and the Richardson number [Formula: see text] ([Formula: see text]) on the fluid flow and heat transfer are investigated with the Reynolds number in the range of [Formula: see text], the Grashof number of [Formula: see text] and the Prandtl number of [Formula: see text]. Flow and thermal performances in the cavity are analyzed in detail by considering the streamlines and isotherms profiles, the average Nusselt number, as well as the total Nusselt number. It is found that the heat transfer efficiency is highest when [Formula: see text] for the cases of the walls moving in the opposite direction. When the walls move in the same directions, the heat transfer efficiency obtained by [Formula: see text] is maximum among the considered values of [Formula: see text]. On the other hand, compared with the cases of [Formula: see text] and [Formula: see text], the cylinder positions corresponding to the largest and the smallest Nusselt numbers are very sensitive to the moving direction of the walls for [Formula: see text]. Moreover, the results also show that in terms of the value of Nusselt number and the stability the case of both walls moving downwards works well. Besides, the effect of the distance between neighboring cylinders is also discussed, it is found that increasing or decreasing the spacing between cylinders could enhance heat transfer to different degrees for the range of [Formula: see text] number considered. Finally, the empirical relationships among [Formula: see text], [Formula: see text], and the spacing between the cylinders ([Formula: see text]) are given, and predictive results match with the computed values very well.

Thermo-bioconvection of oxytactic microorganisms in porous media in the presence of magnetic field

PurposeThis study aims to explore magnetohydrodynamic (MHD) thermo-bioconvection of oxytactic microorganisms in multi-physical directions addressing thermal gradient, lid motion, porous substance and magnetic field collectively using a typical differentially heated two-sided lid-driven cavity. The consequences of a range of pertinent parameters on the flow structure, temperature, oxygen isoconcentration and microorganisms’ isoconcentration are examined and explained in great detail.Design/methodology/approachTwo-dimensional governing equations in a two-sided lid-driven porous cavity heated differentially and packed with oxytactic microorganisms under the influence of the magnetic field are solved numerically using the finite volume method-based computational fluid dynamics code. The evolved flow physics is analyzed assuming a steady laminar incompressible Newtonian flow within the validity of the Boussinesq approximation. The transport of oxytactic microorganisms is formulated by augmenting the continuum model.FindingsThe mechanisms involved with MHD-mixed thermo-bioconvection could have potential benefits for industrial exploitation. The distributions of fluid flow, temperature, oxygen and motile microorganisms are markedly modified with the change of convection regime. Both speed and direction of the translating walls significantly influence the concentration of the motile microorganisms. The concentration of oxygen and motile microorganisms is found to be higher at the upper portion of the cavity. The overall patterns of the fluid flow, temperature and the oxygen and microorganism distributions are markedly affected by the increase of magnetic field strength.Research limitations/implicationsThe concept of the present study could be extended to other areas of bioconvection in the presence of gravity, light or chemical attraction.Practical implicationsThe findings of the present study could be used to multi-physical applications like biomicrosystems, pollutant dispersion in aquifers, chemical catalytic converters, geothermal energy usage, petroleum oil reservoirs, enhanced oil recovery, fuel cells, thermal energy storage and others.Originality/valueThe MHD-mixed thermo-bioconvection of oxytactic microorganisms is investigated under different parametric conditions. The effect of pertinent parameters on the heat and mass transfers are examined using the Nusselt number and Sherwood number.

Attractors for the motion of a finite-size particle in a two-sided lid-driven cavity

Abstract

Numerical analysis and explore of asymmetrical fluid flow in a two-sided lid-driven cavity

The two-dimensional asymmetrical flow in a two-sided lid-driven square cavity is numerically analyzed by the finite volume method (FVM). The top and bottom walls slide in parallel and antiparallel motions with various velocity ratio (UT/Ub=λ) where |λ|=2, 4, 8, and 10. In this study, the Reynolds number Re1 = 200, 400, 800 and 1000 is applied for the upper side and Re2 = 100 constant on the lower side. The numerical results are presented in terms of streamlines, vorticity contours and velocity profiles. These results reveal the effect of varying the velocity ratio and consequently the Reynolds ratio on the flow behaviour and fluid characteristics inside the cavity. Unlike conventional symmetrical driven flows, asymmetrical flow patterns and velocity distributions distinct the bulk of the cavity with the rising Reynolds ratio. For λ>2, in addition to the main vortex, the parallel motion of the walls induces two secondary vortices near the bottom cavity corners. however, the antiparallel motion generates two secondary vortices on the bottom right corner. The parallel flow proves affected considerably compared to the antiparallel flow.

Presenting two new empirical models for calculating the effective dynamic viscosity and thermal conductivity of nanofluids

In this paper, two new empirical equations for calculating the effective dynamic viscosity and thermal conductivity of nanofluids are presented based on a high number of experimental data available in the literature. These two equations present the effective dynamic viscosity and thermal conductivity of nanofluids as a function of the volume fraction (0 ≤ ϕ ≤ 12%), size (10nm ≤ dp ≤ 5μm) and type (Ag, Cu, Al2O3, TiO2, CuO, SiO2, ZnO, MgO, Fe, Fe3O4, Al, AlN, CaCO3) of the nanoparticles, temperature and thermo-physical properties of the base fluid. The proposed models are compared with frequent used models in literature (Brinkman and Maxwell-Garnett models) and found that these classical models severely underestimate the effective viscosity and thermal conductivity of nanofluids. Two proposed models are also compared with some other theoretical models, as those of Chon, Patel, Corcione, Prasher, Koo, Maiga, Masoumi, etc. The results showed that, present models for spherical nanoparticle are in excellent agreement with experimental data and provide more accurate character predictions for thermos-physical properties of nanofluid in comparison with existing models. In addition, five new equations are also proposed using the least squares method for calculating the viscosity of five common working fluids (Water, Glycerol, Ethylene glycol (EG), Propylene glycol (PG) and Ethanol) as a function of the temperature. Beside the pure comparison between these models, two well-known benchmark cases of conjugate natural (Differentially Heated Cavity) and mixed convection (Two-sided Lid-driven Cavity) of nanofluid are chosen in order to investigate the effects of the volume fraction, size and type of the nanoparticles on the fluid flow and heat transfer performance of nanofluids. Easy to use for numerical simulation purposes, covering a wide range of the solid particle size and having high accuracy in predicting thermos-physical properties of nanofluids make these equations useful and practical for the design of various thermal engineering systems such as heat exchangers.

Asymmetrical Flow Driving in Two-Sided Lid-Driven Square Cavity with Antiparallel Wall Motion

The two-dimensional flow in a two-sided lid-driven cavity is often handled numerically for the same imposed wall velocities (symmetrical driving) either for parallel or antiparallel wall motion. However, in this study, we present a finite volume method (FVM) based on the second scheme of accuracy to numerically explore the steady two-dimensional flow in a two-sided lid-driven square cavity for antiparallel wall motion with different imposed wall velocities (asymmetrical driving). The top and the bottom walls of the cavity slide in opposite directions simultaneously at different velocities related to various imposed velocity ratios, λ = -2, -6, and -10, while the two remaining vertical walls are stationary. The results show that varying the velocity ratio and consequently the Reynolds ratios have a significant effect on the flow structures and fluid properties inside the cavity.

Finite-size Lagrangian coherent structures in a two-sided lid-driven cavity

Finite-size Lagrangian coherent structures can arise in dilute suspensions solely because of the size of the particles. When moving near boundaries, a lubrication-induced drag transfers the particles from the chaotic sea of the unperturbed fluid flow to particular Kolmogorov-Arnold-Moser tori.