Showing papers in "Numerical Heat Transfer Part A-applications in 2013"
TL;DR: In this article, three kinds of water-cooled micro-channel heat sinks, such as a rectangular straight microchannel heat sink, a single-layer wavy micro channel heat sink and a double-layer WMC heat sink were designed and the corresponding laminar flow and heat transfer have been investigated numerically.
Abstract: Various microchannel heat sinks for dissipating heat loads have received great attention. Wavy channels are recognized to be suitable to enhance the heat transfer, and are successfully applied in heat-exchange devices. In this article, three kinds of water-cooled microchannel heat sinks, such as a rectangular straight microchannel heat sink, a single-layer wavy microchannel heat sink and a double-layer wavy microchannel heat sink, have been designed and the corresponding laminar flow and heat transfer have been investigated numerically. The effects of the wave amplitude on heat transfer, pressure drop, and thermal resistance are also observed. Results show that for removing an identical heat load, the overall thermal resistance of the single-layer wavy microchannel heat sink decreases with increasing volumetric flow rate, but the pressure drop is increased greatly. At the same flow rate, the double-layer wavy microchannel heat sinks can reduce not only the pressure drop but also the overall thermal resist...
105 citations
TL;DR: In this paper, three kinds of liquid-cooling double-layer microchannel heat sinks, such as a rectangular straight micro-channel heat sink, a parallel-flow wavy micro channel heat sink and a counter-flow double layer wavy heat sink have been designed and the corresponding laminar flow and heat transfer have been investigated numerically.
Abstract: Applications of microchannel heat sinks for dissipating heat loads have received great attention. Wavy channels are recognized to be an alternative cooling technology to enhance the heat transfer, and are successfully applied in heat exchangers. In this article, three kinds of liquid-cooling double-layer microchannel heat sinks, such as a rectangular straight microchannel heat sink, a parallel-flow wavy microchannel heat sink, and a counter-flow double-layer wavy microchannel heat sink, have been designed and the corresponding laminar flow and heat transfer have been investigated numerically. The effects of the wave amplitude and volumetric flow ratio on heat transfer, pressure drop, and thermal resistance are also observed. Results show that the counter-flow double-layer wavy microchannel heat sink is superior at a larger flow rate, and a more uniform temperature rise is achieved. For a slightly larger flow rate, the parallel flow layout shows better performance. In addition to the overall thermal resist...
73 citations
TL;DR: A review of previous studies on turbulence in the frame of Lattice Boltzmann method is presented in this paper, where three main groups of turbulence simulation: DNS, LES and RANS methods.
Abstract: The Lattice Boltzmann Method (LBM) is a potent numerical technique based on kinetic theory, which has been effectively employed in various complicated physical, chemical, and fluid mechanics problems. In recent years, turbulent flow simulation by using this new class of computational fluid dynamics technique has attracted more attention. In this article, a review of previous studies on turbulence in the frame of LBM is presented. Recent extensions of this method are categorized based on three main groups of turbulence simulation: DNS, LES and RANS methods.
71 citations
TL;DR: In this article, an experimental and numerical study on the heat transfer of α-Al2O3/water nanofluid flowing through the double pipe and shell and tube heat exchangers, under laminar flow conditions, is presented.
Abstract: This research presents an experimental and numerical study on the heat transfer of α-Al2O3/water nanofluid flowing through the double pipe and shell and tube heat exchangers, under laminar flow conditions. Effects of important parameters such as hot and cold volume flow rates, nanofluid temperature, and nanoparticles concentration on the heat transfer characteristics are investigated. The results indicated that the heat transfer performance of both double pipe and shell and tube heat exchangers increases with increasing the hot and cold volume flow rates, as well as the particle concentrations and nanofluid inlet temperature. Compared with pure water, the results indicated that the heat transfer coefficients of nanofluid in the double pipe and shell and tube heat exchangers are higher than those of water by 13.2% and 21.3%, respectively. Also, the heat transfer performance of nanofluid in a shell and tube heat exchanger is 26.2% higher than the double pipe heat exchanger. A computational fluid dynamics (C...
67 citations
TL;DR: In this article, the Lattice Boltzmann Method (LBM) was used to solve conjugate heat transfer by using one energy equation for solid and fluid phases, and the effects of extended surfaces were investigated on the rate of heat transfer and pressure drop.
Abstract: The Lattice Boltzmann Method (LBM) is utilized to investigate conjugate heat transfer. Hot and cold streams enter the computational domain, and heat transfer takes place between the two streams through a finite thickness and finite thermal conductivity wall. The main objective of the work is to demonstrate that LBM can solve conjugate heat transfer by using one energy equation for solid and fluid phases. The flux continuity insures automatically. Furthermore, the effects of extended surfaces were investigated on the rate of heat transfer and pressure drop.
64 citations
TL;DR: In this paper, a turbulent forced convection flow of dilute water/TiO2 nanofluid with a particle diameter equal to 30nm in a horizontal circular tube exposed to convection with saturated steam at the wall, is numerically analyzed.
Abstract: In this article, turbulent forced convection flow of dilute water/TiO2 nanofluid with a particle diameter equal to 30 nm in a horizontal circular tube exposed to convection with saturated steam at the wall, is numerically analyzed. Two different approaches are taken into consideration: single and two-phase mixture models. It is comprehended that the convective heat transfer coefficient increases with the particle volume concentration and Reynolds number. On the other hand, the mixture model was in better agreement with experimental data than the single phase approach.
63 citations
TL;DR: In this article, heat transfer and entropy generation characteristics are numerically investigated in the presence of single and double obstructive blocks within a square enclosure, and it is found that the adiabatic block(s) enhance the heat transfer marginally up to a critical size in a convection-dominated regime.
Abstract: In the present work, heat transfer and entropy generation characteristics are numerically investigated in presence of single and double obstructive blocks within a square enclosure. It is found that the adiabatic block(s) enhance(s) the heat transfer marginally up to a critical size in a convection-dominated regime. On the other hand, the enhancement parameter is observed to be more with an increase in block size in a lower range of Rayleigh numbers for an isothermal block. The entropy generation for thermal irreversibility is observed to be several orders higher than that due to viscous dissipation in all cases.
62 citations
TL;DR: In this article, the Beavers-Joseph empirical boundary condition is considered at the fluid-porous interface with the Darcy model for the porous layer and the Boussinesq approximation for the pure fluid and the governing equations formulated in dimensionless variables, such as the stream function, the vorticity and the temperature have been solved by a finite difference method.
Abstract: Transient natural convection in a vertical cylinder containing both a fluid layer overlying a horizontal porous layer saturated with the same fluid and heat-conducting solid shell of finite thickness in conditions of convective heat exchange with an environment has been studied numerically The Beavers-Joseph empirical boundary condition is considered at the fluid-porous interface with the Darcy model for the porous layer and the Boussinesq approximation for the pure fluid The governing equations formulated in dimensionless variables, such as the stream function, the vorticity, and the temperature have been solved by a finite difference method Particular efforts have been focused on the effects of five types of influential factors, such as the Darcy number 10−5 ≤ Da ≤ 10−3, the porous layer height ratio 0 ≤ d/L ≤ 1, the solid shell thickness ratio 01 ≤ l/L ≤ 03, the thermal conductivity ratio 1 ≤ k1,3 ≤ 20, and the dimensionless time 0 ≤ τ ≤ 1000 on the fluid flow and heat transfer Comprehensive anal
59 citations
TL;DR: In this article, a numerical study has been performed on buoyancy-induced convection in a square porous cavity, where the vertical sidewalls of the cavity are maintained with sinusoidal temperature distribution.
Abstract: A numerical study has been performed on buoyancy-induced convection in a square porous cavity. The vertical sidewalls of the cavity are maintained with sinusoidal temperature distribution. The finite volume method is used to numerically solve the nondimensional governing equations. The Brinkman Forchheimer extended Darcy model is used in the present study. The results are analyzed over a range of the amplitude ratio, phase deviation, porosity, and Grashof and Darcy numbers. It is found that the heat transfer rate is increased when increasing the amplitude ratio, porosity, and Darcy number. The nonuniform heating on both sidewalls provides higher heat transfer rate than the nonuniform heating of one wall.
56 citations
TL;DR: In this paper, the conjugate natural convection-conduction heat transfer in a square domain composed of a cavity heated by a triangular solid wall was studied under steady state condition.
Abstract: The conjugate natural convection-conduction heat transfer in a square domain composed of a cavity heated by a triangular solid wall is studied under steady state condition. The vertical and horizontal walls of the triangular solid are kept isothermal and at the same hot temperature T h . The other boundaries surrounding the porous cavity are kept adiabatic except the right vertical wall, where it is kept isothermally at the lower temperature T c . Equations governing the heat transfer in the triangular wall and heat and fluid flow, based on the Darcy model, in the fluid-saturated porous medium together with the derived relation of the interface temperature are solved numerically using the second order central differences finite difference scheme with the successive over relaxation (SOR) method. The investigated parameters are the Rayleigh number Ra (100-1000), solid to fluid saturated porous medium thermal conductivity ratio Kr (0.1–10), and the triangular wall thickness D (0.05-1). The results are presen...
53 citations
TL;DR: In this paper, a DSMC solver was used to study the nonequilibrium effects on monatomic and diatomic rarefied flows in micro/nano lid-driven cavity.
Abstract: In the current study, we performed a DSMC investigation to study the nonequilibrium effects on monatomic and diatomic rarefied flows in micro/nano lid-driven cavity. Our DSMC solver is parallel and benefits from a variable time step algorithm. The results of our simulation showed that growing rarefaction effects increase the maximum temperature of the cavity flow. As the inter-molecular rate of collision diminishes in the nonequilibrium regime, molecules manage to conserve their obtained energy from diffused surfaces; consequently, the flow temperature increases. We also investigate the nonequilibrium effects on the shear stress profile in the micro/nano cavity. Although increasing the Knudsen number decreases flow shear stress, the nondimensional shear stress, which shows the molecular potential for performing collision in the rarefied flow, increases.
TL;DR: Natural ventilation is a sustainable technology that can provide a well-built environment and also save energy as discussed by the authors. But the application of natural ventilation to buildings requires a careful approach in th...
Abstract: Natural ventilation is a sustainable technology that can provide a well-built environment and also save energy. The application of natural ventilation to buildings requires a careful approach in th...
TL;DR: In this paper, a natural convection boundary layer flow of thermally radiating fluid along a heated vertical wavy surface is analyzed, where the radiative component of heat flux emulates the surface temperature.
Abstract: In this study, natural convection boundary layer flow of thermally radiating fluid along a heated vertical wavy surface is analyzed. Here, the radiative component of heat flux emulates the surface temperature. Governing equations are reduced to dimensionless form, subject to the appropriate transformation. Resulting dimensionless equations are transformed to a set of parabolic partial differential equations by using primitive variable formulation, which are then integrated numerically via iterative finite difference scheme. Emphasis has been given to low Prandtl number fluid. The numerical results obtained for the physical parameters, such as, surface radiation parameter, R, and radiative length parameter, ξ, are discussed in terms of local skin friction and Nusselt number coefficients. Comprehensive interpretation of velocity distribution is also given in the form of streamlines.
TL;DR: In this paper, a numerical investigation was carried out on circular jet impingement heat transfer from a constant temperature circular cylinder to understand the major parameters which influence the fluid flow and heat transfer characteristics.
Abstract: A numerical investigation was carried out on circular jet impingement heat transfer from a constant temperature circular cylinder to understand the major parameters which influence the fluid flow and heat transfer characteristics. In this study, air was considered as the working fluid. The flow was considered to be three-dimensional, incompressible, and turbulent. To select a suitable turbulence model for the parametric study, numerical simulations were carried out with standard k-ϵ, standard k-ω, RNG k-ϵ, Realizable k-ϵ, and SST k-ω turbulence models for modeling Reynolds stress terms. Simulations were also carried out using four low Reynolds number models. The results obtained using these models were compared with the available experimental results of jet impingement heat transfer from circular cylinder. It was identified that the RNG k-ϵ model predicts heat transfer characteristics better compared to all other turbulence models considered in this study. Using this turbulence model, a parametric study w...
TL;DR: In this paper, a dual reciprocity boundary element (DRBEM) was extended to study the generalized magneto-thermo-viscoelastic problem in a rotating solid of functionally graded material (FGM) in the context of the Green and Naghdi theory of type III.
Abstract: A numerical model based on the dual reciprocity boundary element method (DRBEM) is extended to study the generalized magneto-thermo-viscoelastic problem in a rotating solid of functionally graded material (FGM) in the context of the Green and Naghdi theory of type III. The material properties of the solid have a gradient in the thickness direction and are anisotropic in the plane of the solid. An implicit-implicit staggered strategy was developed and implemented for use with the DRBEM to obtain a solution for the displacement and temperature fields. The accuracy of the proposed method was examined and confirmed by comparing the obtained results with those known previously. In the case of three-dimensional, a numerical scheme for the implementation of the method is presented and the numerical computations are presented graphically to show the effect of the energy dissipation on the temperature and displacement components.
TL;DR: In this paper, the results of a numerical study of laminar natural convection in a U-shaped enclosure that is filled with a water-Cu nanofluid and is under the influence of a horizontal magnetic field were presented.
Abstract: This article presents the results of a numerical study of laminar natural convection in a U-shaped enclosure that is filled with a water-Cu nanofluid and is under the influence of a horizontal magnetic field. A computational domain was defined and a numerical scheme based on the control volume formulation using the SIMPLE algorithm was developed. The convection-diffusion terms were discretized using a power-law scheme. The effects of the Rayleigh number, the solid volume fraction, the Hartmann number, and the enclosure aspect ratio on the heat transfer performance of the enclosure were examined. The thermal performance of the enclosure was found to be a function of the enclosure aspect ratio. The results also showed that the heat transfer rate increased with an increase of the Rayleigh number and the solid volume fraction, but it decreased with an increase of the Hartmann number.
TL;DR: In this paper, the authors present an open-source mixed symbolic-numerical computational code named unified integral transforms (UNIT) that provides a computational environment for finding hybrid numerical-analytical solutions of linear and nonlinear partial differential systems via integral transforms.
Abstract: The present work summarizes the theory and describes the algorithm related to an open-source mixed symbolic-numerical computational code named unified integral transforms (UNIT) that provides a computational environment for finding hybrid numerical-analytical solutions of linear and nonlinear partial differential systems via integral transforms. The reported research was performed by employing the well-established methodology known as the generalized integral transform technique (GITT), together with the symbolic and numerical computation tools provided by the Mathematica system. The main purpose of this study is to illustrate the robust precision-controlled simulation of multidimensional nonlinear transient convection-diffusion problems, while providing a brief introduction of this open source implementation. Test cases are selected based on nonlinear multidimensional formulations of Burgers’ equation, with the establishment of reference results for specific numerical values of the governing parameters. ...
TL;DR: In this paper, numerical results of natural convection within an air filled square cavity with its horizontal walls submitted to different heating models are reported. But the remaining vertical walls are considered adiabatic and their existence ranges are delineated and, in the limits of the existence range of each solution, the transitions observed are identified and described.
Abstract: The present article reports numerical results of natural convection within an air filled square cavity with its horizontal walls submitted to different heating models. The temperature of the bottom horizontal surface (hot temperature) is maintained constant, while that of the opposite surface (cold temperature) is varied sinusoidally with time. The remaining vertical walls are considered adiabatic. The parameters governing the problem are the amplitude (0 ≤ a ≤ 0.8) and the period (τ ≥ 0.001) of the variable temperature, the Rayleigh number (103 ≤ Ra ≤ 7 × 106), and the Prandtl number (Pr = 0.71). In constant cooling conditions (a = 0), up to three different solutions (monocellular flow MF, bicellular vertical flow BVF, and bicellular horizontal flow BHF) are obtained. Their existence ranges are delineated and, in the limits of the existence range of each solution, the transitions observed are identified and described. In the variable cooling conditions, the effect of the amplitude and the period of the e...
TL;DR: In this paper, a hybrid multi-objective evolutionary approach was used to achieve an acceptable compromise between two competing objectives: the enhancement of film cooling effectiveness and the reduction of aerodynamic loss.
Abstract: Multi-objective shape optimization of a row of laidback fan-shaped film cooling holes has been performed using a hybrid multi-objective evolutionary approach in order to achieve an acceptable compromise between two competing objectives: the enhancement of film cooling effectiveness and the reduction of aerodynamic loss. In order to perform comprehensive optimization of a film cooling hole shape, the injection angle of the hole, lateral expansion angle of the diffuser, forward expansion angle of the hole, and pitch-to-hole diameter ratio are chosen as design variables. Forty experimental designs within the design spaces are selected using the Latin hypercube sampling method. The response surface approximation method is used to construct the surrogate using objective function values calculated at the experimental points using Reynolds-averaged Navier-Stokes analysis. The shear stress transport turbulence model is used as a turbulence closure. The optimization results are processed using the Pareto-optimal m...
TL;DR: In this paper, an adaptive-network-based fuzzy inference system (ANFIS) method is trained and validated using Bhatnagar-Gross-Krook (BGK) Lattice Boltzmann model results.
Abstract: Heat transfer behavior in a 2-D square lid-driven cavity has been studied for various pertinent Reynolds and Rayleigh numbers. The lattice Boltzmann method, a numerical tool based on the particle distribution function is applied to simulate a thermal fluid flow problem. Bhatnagar-Gross-Krook (BGK) is combined with the double population thermal Lattice Boltzmann model to solve mixed convection in a square cavity. An adaptive-network-based fuzzy inference system (ANFIS) method is trained and validated using BGK Lattice Boltzmann model results. The results show that the trained ANFIS model successfully predicts the temperature and flow fields in a few seconds with acceptable accuracy.
TL;DR: In this paper, numerical simulations were performed to understand the thermo-magneto-convective transport of fluid and heat in a vertical lid-driven square enclosure following a finite volume approach based on the SIMPLEC algorithm.
Abstract: Numerical simulations are performed to understand the thermo-magneto-convective transport of fluid and heat in a vertical lid-driven square enclosure following a finite volume approach based on the SIMPLEC algorithm. The enclosure is filled with an electrically conducting fluid and having a heated source on the right vertical wall. Two different types of sources, such as a semicircular and a rectangular one, are considered. Both the top and bottom horizontal walls and the right vertical wall, except the source of the enclosure, are assumed insulated and the left vertical wall and the sources are kept isothermal with different temperatures. The left vertical wall is also translating in its own plane at a uniform speed, while all other walls are stationary. Two cases of translational lid motion, viz., vertically upward and downward are considered. A uniform magnetic field is applied along the horizontal direction normal to the translating wall. Shear forces due to lid motion, buoyancy forces as a result of ...
TL;DR: In this article, the authors investigated the effect of nanoparticles on heat transfer in the presence of a magnetic field in the case of a low Rayleigh number and a moderate and high Rayleigh numbers.
Abstract: The current work investigated, numerically, enhancement of heat transfer in natural convection using CuO-water nanofluid in the presence of a magnetic field. The governing equations were discretized using the control volume method and solved numerically via the SIMPLE algorithm. For the case of absence of a magnetic field and for low Rayleigh number, the heat transfer was almost insensitive to the presence of nanoparticles. For moderate and high Rayleigh numbers, the presence of nanoparticles had an adverse effect on heat transfer at high volume fraction of nanoparticles. The highest reduction in heat transfer was registered for the case of Ra = 105. Contour maps are generated for the normalized Nusselt number (Nu*) to determine the optimum selection of volume fraction of nanoparticles and magnetic field that gives maximum heat transfer enhancement. The results demonstrated the effectiveness and practicality of using high values of magnetic field in enhancing heat transfer using nanofluids.
TL;DR: In this paper, the entropy generation analysis has been introduced to investigate the effectiveness in heat transfer during natural convection within porous rhombic enclosures of various inclination angles ϕ for differential (case 1) and Rayleigh Benard (case 2), heating situations.
Abstract: Entropy generation analysis has been introduced to investigate the effectiveness in heat transfer during natural convection within porous rhombic enclosures of various inclination angles ϕ for differential (case 1) and Rayleigh Benard (case 2), heating situations. The results are presented in terms of streamlines (ψ), isotherms (θ), and entropy generation maps (S θ and S ψ ). Entropy production on the basis of various heating patterns and geometrical orientations have been reported based on the relation between total entropy generation (Stotal) and average Nusselt number via Bejan Number, which relates the available thermal energy to irreversibilities.
TL;DR: In this article, a numerical study of forced convective heat transfer from elliptic cylinders of various axis ratios (AR, AOA, and Reynolds numbers) is presented for both isothermal and isoflux wall boundary conditions.
Abstract: This article presents the numerical study of laminar forced convective heat transfer from elliptic cylinders of various axis ratios (AR = 0.1, 0.4, 0.6, 0.8, and 1.0), angles of attack (AOA = 30°, 45°, 60°, and 90°), and Reynolds numbers (Re = 50, 100, 150, and 200). Simulations are carried out for both isothermal and isoflux wall boundary conditions. A detailed study of flow field reveals distinct instantaneous and time-averaged flow patterns behind the elliptic cylinder. The effect of flow patterns on isotherms and, thus, on heat transfer, is analyzed in detail. Local and surface averaged Nusselt number (Nu and Nu avg ) is computed and their variation due to change in AR, AOA, and Re is studied. It is observed that increasing AR and Re increases Nu avg monotonically, while increasing AOA decreases Nu avg . Finally, correlations are proposed for Nu avg with respect to AR, AOA, and Re with minimum rms error.
TL;DR: In this paper, the inverse analysis of a transient conduction-radiation heat transfer problem using differential evolution (DE) is studied, and the effects of key DE algorithm parameters, such as the weighting factor and the crossover constant on the quality of solutions are studied.
Abstract: This article deals with the application of the differential evolution (DE) algorithm for the inverse analysis of a transient conduction-radiation heat transfer problem. Thermophysical properties and/or optical properties of the medium are simultaneously retrieved with a known temperature field. The conducting-radiating planar enclosed medium bounded by diffuse-gray boundaries is absorbing, emitting, and scattering. In both the direct and inverse methods, the energy equations are solved using the lattice Boltzmann method (LBM), and the finite volume method (FVM) is used to compute the radiative information. In the inverse method, the objective function is minimized using the DE algorithm. Any two sets of parameters, viz., the extinction coefficient, the scattering albedo, emissivity and conduction-radiation parameter, are simultaneously retrieved. The effects of key DE algorithm parameters, such as the weighting factor and the crossover constant on the quality of solutions, are studied. Measurement errors ...
TL;DR: In this article, a numerical study of natural convection in a vertical annulus filled with a fluid-saturated porous medium, and with internal heat generation subject to a discrete heating from the inner wall is examined via the Brinkman extended Darcy equation.
Abstract: This article reports a numerical study of natural convection in a vertical annulus filled with a fluid-saturated porous medium, and with internal heat generation subject to a discrete heating from the inner wall. The relative importance of discrete heating on natural convection in the porous annulus is examined via the Brinkman-extended Darcy equation. The inner wall of the annulus has a discrete heat source and the outer wall is isothermally cooled at a lower temperature. The top and bottom walls and the unheated portions of the inner wall are kept adiabatic. The governing equations are numerically solved using an implicit finite difference method. A wide range of numerical simulations is conducted to understand the effects of various parameters like heat source length, heat source location, Darcy number, radius ratio, and Rayleigh numbers due to external and internal heating on the flow and heat transfer. The numerical results reveal that the placement of the heater near the middle portion of the inner ...
TL;DR: A comprehensive survey of the literature in the area of numerical heat transfer (NHT) published in 2010 and 2011 has been conducted as mentioned in this paper, which can be used as a starting point for future work.
Abstract: Here a comprehensive survey of the literature in the area of numerical heat transfer (NHT) published in 2010 and 2011 has been conducted. Due to the immenseness of the literature volume, journals s...
TL;DR: In this paper, the authors employed arrays of different shapes of surface dimples to determine the most optimal configurations for augmenting surface heat transfer rates, as pressure drop penalties are minimized, where the dimples in these arrays are aligned with each other, as they are located on one surface of a square cross-section channel in six different streamwise rows.
Abstract: The present study employs arrays of different shapes of surface dimples to determine the most optimal configurations for augmenting surface heat transfer rates, as pressure drop penalties are minimized. Six different dimple shapes are investigated (spherical indentation (case A), super-ellipse (case D), two ellipse-spherical arrangements with the long axis oriented both parallel and normal to the bulk flow direction (cases B1 and B2, respectively), and two egg-spherical arrangements with the half ellipse with longer axis pointed both away and towards the bulk flow direction (cases C1 and C2, respectively). The dimples in these arrays are aligned with each other, as they are located on one surface of a square cross-section channel in six different streamwise rows. All turbulent fluid flow and surface heat transfer results are obtained using computation fluid dynamics with a k−ϵ RNG turbulence model, and constant heat flux thermal boundary conditions applied to all channel surfaces. Flow development is prov...
TL;DR: In this paper, the authors presented a two-dimensional numerical study on the fluid flow and mixed convection heat transfer around two equal isothermal square cylinders placed in a tandem arrangement and subjected to the cross flow of a Newtonian fluid at moderate Reynolds numbers.
Abstract: This article presents a two-dimensional numerical study on the fluid flow and mixed convection heat transfer around two equal isothermal square cylinders placed in a tandem arrangement and subjected to the cross flow of a Newtonian fluid at moderate Reynolds numbers. The spacing between the cylinders is varied by changing the gap to cylinder size ratio as S/d = 1, 2, 3, 4, 5, 7, and 10. The Reynolds number is considered in the range 50 ≤ Re ≤ 150. The mixed convection effect is studied for Richardson number range of 0–2, and the Prandtl number is chosen constant as 0.71. The flow is considered in an unbounded medium; however, fictitious confining boundaries are chosen to make the problem computationally feasible. Numerical calculations are performed by using a PISO algorithm-based finite volume solver in a collocated grid system. The effect of superimposed thermal buoyancy on flow and isotherm patterns are presented and discussed. The global flow and heat transfer quantities such as overall drag and lift ...
TL;DR: In this article, the quasi stationary state solution of the two-dimensional Rosenthal equation for a moving heat source using the meshless element free Galerkin method is studied, where node-based moving least square approximants are used to approximate the temperature field.
Abstract: The quasi stationary-state solution of the two-dimensional Rosenthal equation for a moving heat source using the meshless element free Galerkin method is studied in this article. Node-based moving least square approximants are used to approximate the temperature field. Essential boundary conditions are enforced by using Lagrange multipliers. A Gaussian surface heat source is used for the modeling of the moving heat source. The results obtained for a two-dimensional model are compared with the results of the finite-element method.