Cubical Cavity Research Articles

3D-Numerical simulation of free convection inside a cubical cavity filled with non-Newtonian-Bingham fluid

This work focuses on a numerical study of the natural convection of a non-Newtonian viscoplastic fluid within a cubic enclosure. The viscoplastic behavior is described by the Bingham model. The considered three-dimensional convective flow is confined within a cavity, subjected to a horizontal temperature gradient, where the vertical walls have two imposed temperatures while the rest of the walls are adiabatic. The Navier-Stokes equations, along with the mass and energy conservation equations, are numerically solved. Fluid flow and heat transfer characteristics are systematically studied over a wide range of Rayleigh numbers Ra (103 - 106) and Bingham number Bn (0 - 20). Finally, comparisons were made with previous results obtained in two dimensions in order to analyze the existence of a three-dimensional effect on the flow of the Bingham fluid. The results show that the Nusselt number decreases with the increase of the Bingham number, and for the large values ​​of the latter the heat transfer is done by conduction. It is also noteworthy that the critical Bn of the 2D model is higher than that of the 3D model, which confirms the existence of the three-dimensional effect. This is attributed to the presence of a wall along the Z axis which hinders and limits the flow of fluid within the enclosure.

Numerical simulation of natural convection in a differentially heated cubical cavity with solid fins

PurposeThe performance of solid fins inside a differentially heated cubical cavity is numerically studied in this paper. The main purpose of the study is to make an optimization to reach the maximum heat transfer in the enclosure having the solid fins with studied parameters.Design/methodology/approachThe considered domain of interest is a differentially heated cube having heat-conducting solid fins placed on the heated wall while an opposite wall is a cooled one. Other walls are adiabatic. Governing equations describing natural convection in the fluid filled cube and heat conduction in solid fins have been written using non-dimensional variables such velocity and vorticity taking into account the Boussinesq approximation for the buoyancy force and ideal solid/fluid interfaces between solid fins and fluid. The formulated equations with appropriate initial and boundary conditions have been solved by the finite difference method of the second of accuracy. The developed in-house computational code has been validated using the mesh sensitivity analysis and numerical data of other authors. Analysis has been performed in a wide range of key parameters such as Rayleigh number (Ra = 104–106), non-dimensional fins length (l = 0.2–0.8), non-dimensional location of fins (d = 0.2–0.6) and number of fins (n = 1–3).FindingsFrom numerical methods point of view the used non-primitive variables allows to perform numerical simulation of convective heat transfer in three-dimensional (3D) regions with two advantages, namely, excluding difficulties that can be found using vector potential functions and reducing the computational time compared to primitive variables and SIMPLE-like algorithms. From a physical point of view, it has been shown that using solid fins can intensify the heat transfer performance compared to cavities without any fins. Fins located close to the bottom wall of the cavity have a better heat transfer rate than those placed close to the upper cavity surface. At high Rayleigh numbers, increasing the fins length beyond 0.6 leads to a reduction of the average Nusselt number, and one solid fin can be used to intensify the heat transfer.Originality/valueThe present numerical study is based on hybrid approach for numerical analysis of convective heat transfer using velocity and vorticity that has some mentioned advantages. Obtained results allow intensifying the heat transfer using solid fins in 3D chambers with appropriate location and length.

Cubical radiator for three‐dimensional flexible beam controller with multiple radiation beams and directions

AbstractA novel approach for generation of the multiple three‐directional and controllable beams from a cubical electromagnetic (EM) wave radiator is proposed in this paper. This cubical radiator is a multiple‐mode EM resonator, which is formed by a cubical metal cavity. Three resonant modes are excited in this cavity resonator by a feeding slot. Besides the feeding slot, a few additional slots are opened on the side wall(s) of the cavity to act as the EM wave radiation elements. Various combinations of radiation slots contribute to different beam directions, for example, side‐direction (single radiation slot), edge‐direction (two radiation slots), and vertex‐direction of the cavity (three radiation slots). More combinations of these slots are further studied in the cases of side + edge and edge + vertex to illustrate the diversity in the directions of the produced EM beams. To validate the predicted results, two prototypes are fabricated and measured to display their far‐field radiation patterns. The measured results agree well with the full‐wave simulated ones, thereby demonstrating the possibility of a large number of the flexible EM beams, as well as the capability of the controllable beam directions.

A combined uncertainty and sensitivity analysis of melting in a cubical cavity, Part A: Model validation

Latent heat thermal energy storage systems exploit the solid–liquid phase transition of a material to store thermal energy almost isothermally with high energy density. Numerical methods are increasingly being used for the targeted design of these storage systems. The problem, however, is that the results obtained with these methods – despite a frequently shown near-perfect agreement between validation experiments and simulation results – are subject to large uncertainty. To illustrate the extent of this problem and to show approaches to solving it, a combined uncertainty and sensitivity analysis of the melting process of a paraffin (octadecane) in a cuboid heated from one side is carried out in this two-paper series. In part A, we present the model and validate it; in part B we use it to carry out the combined uncertainty and sensitivity analysis. The validation of the model is performed with the help of experimental results. For this purpose, we measure the liquid phase fraction, the position of the phase boundary, the velocity field in the liquid and the temperature inside the test capsule. We make sure that the experimental results are reproducible. Systematic deviations are discussed and, if possible, the results are corrected for their value. When measuring the velocity field using particle image velocimetry (PIV), the greatest systematic deviation is due to the inhomogeneous refractive index field in the liquid phase. Finally, it is shown that, in the present case, the influence is very low if constant material properties evaluated at the mean temperature are taken for each phase compared to a temperature-dependent implementation. An exception is the density. If the density change during melting is not taken into account the deviation of the melt fraction lies between 6 and 8%. In summary, the validation of the numerical model is very satisfactory and demonstrates the suitability of the model for performing the investigations of the part B paper.

Particle dispersion produced by a turbulent free convection flow in a room-sized cubical cavity

This paper introduces the framework for the ongoing “2024 International CFD Challenge on the Long-Range Indoor Dispersion of Pathogen-Laden Aerosols.” The Challenge is designed as a blind test to assess the accuracy of computationally efficient turbulence modeling techniques, including URANS and LES, in replicating both the hydrodynamics and aerosol dispersion in an idealized indoor environment. To evaluate the simulations, DNS data of turbulent natural flow at a high Rayleigh number within a room-sized enclosure will serve as a reference benchmark. Participants have the flexibility to conduct simulations of the same flow configuration using their preferred CFD software, employing URANS, LES, and/or hybrid methods. The Challenge was officially launched on October 16, 2023, and has garnered participation from 31 teams representing 18 different countries, with the expected submission of results in May 2024. The outcomes of the comparison between the different modelling approaches and the reference DNS will be presented and discussed during the conference.

Direct Numerical Simulation of Mixed Convection Flow in Lid-Driven Cavities

The mixed convection of heat transfer and fluid flow in a - lid drivencubical cavity filled with air is investigated numerically in this study. The computational procedure is based on the finite volume method and a full multigrid acceleration solver. The top wall of the cavity is maintained at a constant high temperature - Th, and it can move with a constant velocity U0. The bottom wall is immobile and maintained at a cold temperature Tc. While, the remaining boundary parts of the cavity are motionless and kept thermally insulated. Several numerical simulations were conducted to investigate mixed convection heat transfer in a sliding cubical cavity for a range of Reynolds numbers from 1000 to 5000 and Richardson numbers from 0.001 to 10. The influence of mixed convection parameters, Reynolds number, Richardson number, and heat transfer rate on the flow behavior was analyzed through parametric studies. The results include flow and heat transfer characteristics, iso-surfaces, and streamlines for the entire range of Richardson numbers and Reynolds numbers investigated. The study shows that as Reynolds number is increased beyond a critical value, the flow becomes unstable and bifurcates.

Experimental and numerical study of mixed convection heat transfer in a vented cavity partially filled with a porous medium: Effects of reynolds and rayleigh numbers on Nusselt number and flow regimes

This article presents a comprehensive investigation of mixed convection flow and heat transfer within a vented, partially side-heated cubical cavity, incorporating a porous medium with low-conductivity square-shaped inclusions. The study encompasses an extensive range of Rayleigh numbers (106 < Ra < 6 × 106) and Reynolds numbers (200 < Re < 4000) while maintaining a fixed Prandtl number of Pr = 0.71. This investigation spans over three decades in Richardson numbers (Ri = Ra/(Re2 Pr)), aiming to discern the interplay between the Nusselt number, Nu, and the Richardson number. Our understanding of Nusselt number dependencies is enhanced by combining PIV measurements of heat transfer and velocity fields with temperature field data. The study uses both experimental and numerical PIV data, incorporating porous media representation to reveal heat transfer scaling with both Reynolds and Rayleigh numbers. Computational Fluid Dynamics (CFD) methods are used to explore the complex physical behavior under different flow conditions. Three distinct flow and heat transfer regimes have been identified, predicated upon the Richardson number. For Ri < 25, the flow structure and Nusselt number exhibit similarities with pure forced convection, where the Nusselt number scales as Nu ∼ Re0.6, independent of the Rayleigh number. Conversely, for Ri > 70, natural convection dominates the vicinity of the heating wall, rendering the Nusselt number less sensitive to Reynolds number variations and predominantly dictated by the Rayleigh number. Notably, the intermediate regime, ranging from 25 < Ri < 70, witnesses a competition between upward-directed natural convection flow at the heating wall and downward-directed forced flow, culminating in a minimum effective Nusselt number.

New higher-order accurate super-compact scheme for three-dimensional natural convection and entropy generation

Exploring natural convection in three dimensions through numerical analysis has become essential for gaining a deeper understanding of this process compared to studying it in just two dimensions. This paper presents an enhanced analysis of three-dimensional (3D) natural convection phenomena within an air-filled cubical cavity, with a primary focus on heat transfer characteristics. The distinguishing feature of this research lies in the pioneering application of the newly developed higher-order accurate super-compact finite difference scheme to study 3D natural convection and entropy generation. This numerical method is renowned for its fourth-order spatial accuracy and second-order temporal accuracy. The super-compact scheme employs 19 grid points at the current time level (nth time level) while utilizing just seven grid points from the subsequent time level [(n+1)th time level. The flow is considered to be 3D, time-varying, laminar, and incompressible. First, the newly developed numerical code has undergone validation through quantitative and qualitative comparisons with existing results. Then, we analyze the flow phenomena and heat transfer dynamics within the cavity for various Rayleigh numbers (102≤Ra≤105) with a fixed Prandtl number (Pr = 0.71) by using this scheme. Various parameters such as local Nusselt numbers, averaged Nusselt numbers, local entropy, Bejan number, streamlines, and isotherm dispersion are studied in this work. It is found that as the Rayleigh number (Ra) increases, the Bejan number (Be) decreases, while the total entropy increases. When the Ra is less than or equal to 104, the Be remains above 0.5, indicating that irreversibility primarily arises from heat transfer. However, as we transition to Ra=105, the Be falls below 0.5, signaling that irreversibility is now predominantly driven by viscous effects. To the best of our knowledge, this research marks a pioneering effort by introducing the application of the higher order super-compact (HOSC) scheme for the examination of heat transfer within a 3D cubic cavity, thus endowing our work with a truly novel and pioneering character. It is worth mentioning that, before this study, there has been no precedent in the exploration of heat transfer using the super-compact scheme, thus endowing our work with a truly novel and pioneering character.

Flow stability and sequence of bifurcations in a cubic cavity driven by a constant shear stress

The progressive destabilisation of the incompressible flow in a cubical cavity driven by a constant shear stress is investigated numerically. To that end, one of the square faces of the cube is subjected to a constant shear stress parallel to two opposite edges of that face. The three-dimensional steady basic flow loses its mirror symmetry through a supercritical pitchfork bifurcation leading to a pair of steady stable non-symmetric flow states that are antisymmetric to each other. Upon increase of the strength of the driving, these non-symmetric equilibria become unstable via a Hopf bifurcation resulting in two limit cycles. The bifurcations are investigated using classical linear stability analyses as well as nonlinear simulations. Upon a further increase of the driving shear stress, the limit cycles destabilise through bursts triggering a complex interplay between the unstable equilibria. The transition to turbulence resembles the Pomeau–Manneville scenario.

THERMAL PERFORMANCE OF IONANOCOLLOIDS IN A CUBICAL CAVITY WITH INTERNAL PROTRUSIONS

Ionic liquids have gained considerable attention as heat transfer fluids due to their unique properties, such as low vapor pressure and high thermal stability, which make them suitable for high-temperature applications. The purpose of this study is to examine the thermal behavior of ionanocolloids in a cubical cavity with an internal protruding heat source. The effect of Brownian motion and turbulence on the flow characteristics and thermal enhancement of ionic liquid dispersed with nanoparticles of silicon dioxide, aluminum oxide, and single-walled carbon nanotubes is investigated. The computations are performed by developing an unsteady, turbulent multiphase mixture model discretized by the finite difference method. The heater aspect ratio (&amp;epsilon;), Grashof number (Gr), and nanoparticle volume concentration (&amp;phi;) are varied in the following ranges, respectively: 0.2 &amp;le; &amp;epsilon; &amp;le; 5, 10&lt;sup&gt;6&lt;/sup&gt; &amp;le; Gr &amp;le; 10&lt;sup&gt;10&lt;/sup&gt;, and 2&amp;#37; &amp;le; &amp;phi; &amp;le; 6&amp;#37;. It is found that the velocity, kinetic energy, and Nusselt number are increasing functions of the heater aspect ratio and particle concentration. The coalescence of the nanoenhanced ionic liquid mixture is phenomenal for its lower heater aspect ratio. The carbon nanotube-dispersed ionanofluid mixture exhibited superior thermal performance for a turbulent Grashof number and enhanced the average Nusselt number of pure ionic liquid by 141.13&amp;#37;. The multiphase model is validated, and results are closer to the benchmark experimental findings.

Numerical simulation of the particle wall mass transfer rates on rough surfaces confining turbulent natural convection flows

We performed numerical simulations of the particle mass transfer rates on the horizontal and vertical thermally active rough walls confining a turbulent natural convection flow. We considered the air flow conditions in a cubical cavity (L=1.22m, Ra=5.4·108, Pr=0.71) with two opposed pairs of consecutive walls at different temperatures, for which measurements of the particle deposition velocities are reported in the literature. The simulations were carried out by solving the momentum, thermal energy and particle mass transfer equations using a series of two-dimensional computational cell units to determine spatial evolution and development of the particle concentration boundary layer in the vicinity of hot and cold rough walls. Different flow conditions, wall orientations, sizes of roughness elements, particle diameters and temperature increments between the wall and the bulk fluid, typically found in indoor environments, have been considered and consequently, results can be used to estimate the particle deposition rates in real scenarios. At large mass transfer particle Péclet numbers, corresponding to spherical particles with diameters of 0.5–1 μm, the wall mass transfer rates of particles on rough textures typically increase by a factor of about 3 in comparison with the deposition on smooth surfaces. The thermophoretic effect significantly decreases the particle deposition on hot surfaces and increases it on cold surfaces, especially at large particle Péclet numbers. The numerical predictions of the deposition velocities are in good agreement with the measurements reported in the literature for the same flow conditions considered.

Three-dimensional non-Darcy free convective heat transfer flow in a bidisperse porous medium within a cubical cavity

Heat transport in porous media, especially in a bidisperse porous matrix, has recently received considerable attention due to its diverse real-life applications in applied science and engineering. In the current study, we employ the Darcy-Brinkman-Forchheimer model and three temperature equations incorporating the local thermal nonequilibrium conditions among the fluid and the porous matrix to examine the three-dimensional free convective heat transfer flow in a bidisperse permeable matrix inside a cubical cavity. The Galerkin weighted residual finite element method simulates the model's non-dimensional governing equations. We examine the effects of the significant model parameters on the flow and heat domains considering (104 ≤ Raf ≤ 106), (103 ≤ Rap ≤ 106), (10−3 ≤ Daf ≤ 10−1), (10−4 ≤ Dap ≤ 10−2),(0.7 ≤ ϕ ≤ 0.9) and (0.4 ≤ ε ≤ 0.7). It is found that the average Nusselt number in the macrophase, microphase, and solid matrix increased with the increase of the macro porosity for about 7.18%, 7.06%, and 9.86%, respectively, when it rises from 0.7 to 0.9. Furthermore, increasing the micro-porosity enhances the rate of heat transfer. As the Raleigh number advances, there is a noticeable increase in heat transfer in both the macrophase and the microphase.

Fully-resolved numerical simulations of the turbulent flow and particle deposition in a cubical cavity with two pairs of differentially heated opposed walls at Rayleigh number 3.6 × 109

Fully-resolved numerical simulations of the turbulent flow and particle deposition in a cubical cavity with two pairs of differentially heated opposed walls at Rayleigh number 3.6 × 109

Scaling of Transient Natural Convection Cooling in Side-Cooled Cavity: The Effect of Variable Viscosity

The transient natural convection of variable and constant viscosity fluids in a side cooled cubical cavity is studied experimentally. The convective flow in the cavity is visualized by the shadowgraph technique. The fluid was initially preheated and enough time is allowed to assure uniform temperature distribution. Temperature difference is introduced by a sudden cooling of the two side walls. The results indicate that the transient flow development is characterized by the following distinct processes: the initial growth of the vertical boundary layer and horizontal intrusions, the interaction of the horizontal intrusions and the stratification. New scaling relations are introduced to include the effect of the viscosity variation with temperature. The new suggested scalings showed good agreement with the measurements based on the shadowgraph images.

Second law analysis of a 3D magnetic buoyancy-driven flow of hybrid nanofluid inside a wavy cubical cavity partially filled with porous layer and non-Newtonian layer

The current paper presents numerical results of the 3D buoyancy-driven flow of a hybrid nanofluid in a cubical cavity in the presence of a magnetic field. The computational domain comprises two layers: a non-Newtonian fluid layer and a hybrid nanofluid layer. The temperature disparity within the domain results from heating the wavy bottom wall and cooling both sidewalls while the top wall is insulated. A magnetic field is applied on the positive z-axis. To encounter the non-Newtonian layer influence, the power-law model is considered. The solution of the governing equations is obtained by the Galerkin FEM method. The effects of geometrical parameters of the problem are discussed and illustrated. The results indicate that by simultaneously using non-Newtonian Fe3O4/MWCNT hybrid nanofluid and porous media, the heat exchange in the 3-D cavity is positively affected by the growth in Rayleigh number, Darcy number as well as the height of the porous layer. Furthermore, it is negatively affected by the rise of the magnetic field, corrugation number, and a minor degree when the flow index n was increased due to the pseudo-plastic fluid's high viscosity and shear force.

Simulation of flow and heat transfer in a differentially heated cubical cavity using coarse Large Eddy Simulation

Two widely used sub-grid scale models namely: the standard and the dynamic Smagorinsky models were tested in a simulation of the flow in a thermally driven 3D cavity at turbulent Rayleigh number Ra = 109. The cubical cavity of 0.7 m side-length is set to have a temperature difference of 39 K between the two facing cold and hot vertical walls. Experimentally measured temperature profiles for both the top and bottom walls were imposed as Dirichlet boundary conditions to implicitly account for wall-to-wall radiation effects. The focus of this research is the response of the subgrid-scale models and their ability to predict the flow in the thermally driven 3D cavity when the mesh resolution is coarse and below optimal LES standards. The research is motivated by investigating a feasible modeling strategy for particulate flows in the differentially heated cavity. As URANS and hybrid RANS-LES models fail to reproduce the flow accurately due to difficulty to model subtle physical mechanisms such as laminarization and three-dimensional effects, the alternative is LES applied on a coarse mesh. In a quantitative manner, the first and second-moment statistics are compared at different locations across the cavity against both previous fine mesh LES and experimental databases. For the first moment statistics, both models globally predict the flow fields well. However, for higher moments, the dynamic model outperforms the standard Smagorinsky model, and its predictions are globally in very good agreement with both reference LES and experimental measurements at a fraction of the CPU power needed for optimal LES. The presented results will motivate a further investigation of particle dispersion in the cubical cavity at moderate computational power.

Entropy analysis during heat dissipation via thermomagnetic convection in a ferrofluid-filled enclosure

Thermomagnetic convection and entropy analysis in a ferrofluid-filled cubical cavity, having a centrally placed cylindrical heat source is investigated numerically. The magnetic field is created by either three normal permanent magnets or two Halbach array magnets. The governing equations are solved using a finite-volume, primitive-variables method. Thermal energy interactions between the heat-generating cylindrical heat source and the fluid are visualized through magnetic field distribution, velocity contours, velocity vectors, static temperature, and heat flux vectors. Also, a volumetric entropy generation analysis has been performed for understanding the quality of heat transfer and evaluating the thermodynamic merit of the heat-dissipation system. Results indicate that there is a considerable enhancement of cooling with both the magnetic arrangements. Parametric study shows that the arrangement with a double-Halbach array yields a slightly better overall performance compared to the one with three normal permanent magnets. Although the heat transfer is found to increase with increasing magnetic field strength, strong advection leads to a higher entropy generation at a large field. An intermediate magnetic Nusselt number is found to provide the optimal cooling amongst the investigated cases.

CFD Simulation of Particle-Laden Flow in a 3D Differentially Heated Cavity Using Coarse Large Eddy Simulation

Particulate flow in closed space is involved in many engineering applications. In this paper, the prediction of particle removal is investigated in a thermally driven 3D cavity at turbulent Rayleigh number Ra = 109 using Coarse Large Eddy Simulation (CLES). The depletion dynamics of SiO2 aerosol with aerodynamic diameters between 1.4 and 14 µm is reported in an Euler/Lagrange framework. The main focus of this work is therefore to assess the effect of the subgrid-scale motions on the prediction of the particulate flow in a buoyancy driven 3D cavity flow when the mesh resolution is coarse and below optimal LES standards. The research is motivated by the feasibility of modeling more complex particulate flows with reduced CPU cost.The cubical cavity of 0.7 m side-length is set to have a temperature difference of 39 K between the two facing cold and hot vertical walls. As a first step, the carrier fluid flow was validated by comparing the first and second-moment statistics against both previous well-resolved LES and experimental databases [Kalilainen (J. Aero Sci. 100:73–87, 2016); Dehbi (J. Aero. Sci. 103:67–82, 2017)]. First moment Eulerian statistics show a very good match with the reference data both qualitatively and quantitatively, whereas higher moments show underprediction due to the lesser spatial resolution. In a second step, six particle swarms spanning a wide range of particle Stokes numbers were computed to predict particle depletion. In particular, predictions of 1.4 and 3.5 µm particles were compared to LES and available experimental data. Particles of low inertia i.e. dp < 3.5 µm are more affected by the SGS effects, while bigger ones i.e. dp = 3.5–14 µm exhibit much less grid-dependency. Lagrangian statistics reported in both qualitative and quantitative fashions show globally a very good agreement with reference LES and experimental databases at a fraction of the CPU power needed for optimal LES.

Numerical Study of MHD Natural Convection inside a Cubical Cavity Loaded with Copper-Water Nanofluid by Using a Non-Homogeneous Dynamic Mathematical Model

Free convective flow in a cubical cavity loaded with copper-water nanofluid was examined numerically by employing a non-homogeneous dynamic model, which is physically more realistic in representing nanofluids than homogenous ones. The cavity was introduced to a horizontal magnetic field from the left sidewall. Both the cavity’s vertical left and right sidewalls are preserved at an isothermal cold temperature (Tc). The cavity includes inside it four isothermal heating blocks in the middle of the top and bottom walls. The other cavity walls are assumed adiabatic. Simulations were performed for solid volume fraction ranging from (0 ≤ ϕ ≤ 0.06), Rayleigh number varied as (103 ≤ Ra ≤ 105), the Hartmann number varied as (0 ≤ Ha ≤ 60), and the diameter of nanoparticle varied as (10 nm ≤ dp ≤ 130 nm). It was found that at (dp = 10 nm), the average Nusselt number declines when Ha increases, whereas it increases as (Ra) and (ϕ) increase. Furthermore, the increasing impact of the magnetic field on the average Nusselt number is absent for (Ra = 103), and this can be seen for all values of (ϕ). However, when (dp) is considered variable, the average Nusselt number was directly proportional to (Ra) and (ϕ) and inversely proportional to (dp).

Transport and wall surface deposition of airborne particles in enclosed, buoyancy-driven turbulent flows using fully-resolved numerical simulations

Airborne particle transport and deposition on solid surfaces play a key role in aerosol deposition, infectious diseases transmission and surface soiling. Moving fluids disperse particles by the action of several forces including drag, lift, thermophoresis, buoyancy and Brownian effects. The relative importance of each contribution depends on the phases density ratio and the particle size. These two parameters, along with the characteristics of the boundary layers, control the local wall deposition rate. Experiments and analytical solutions have provided partial information on deposition velocity for several particle sizes and turbulent intensities in air filled cavities. While experimental data is restricted to few selected wall locations, boundary layer models results only provide wall-average values. Using Direct Numerical Simulations to solve the flow hydrodynamics and Exponential-Lagrangian Tracking Schemes for the disperse phase, deposition rates on each surface of a cubical cavity with oppositely heated walls have been determined. Numerical results at Ra = 5.4 × 108 are in very good agreement with experiments for 0.1 and 0.5 μm particle diameters. Deposition rate on adiabatic walls is found to be spatially inhomogeneous with particles accumulating near the corners where hot and cold walls meet. These preferential spots are explained by intensified wall-normal turbulent transport in these particular regions.