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The purpose of this study is to explore the phase change (PC) dynamics in a T-shaped ventilated cavity having multiple inlet and outlet ports during nanofluid convection with phase change material (PCM) packed bed-installed system.

Finite element method was used to analyze the PC dynamics and phase completion time for encapsulated PCM within a vented cavity during the convection of nanoparticle loaded fluid. The study is performed for different Reynolds number of flow streams (Re₁ and Re₂ between 300 and 900), temperature difference (ΔT₁ and ΔT₂ between −5 and 10), aspect ratio of the cavity (between 0.5 and 1.5) and nanoparticle loading (between 0.02% and 0.1%).

It is observed that phase transition can be controlled by assigning different velocities and temperatures at the inlet ports of the T-shaped cavity. The PC becomes fast especially when the Re number and temperature of fluid in the port vary closer to the wall (second port). When the configurations with the lowest and highest Re number of the second port are considered up to 54.7% in reduction of complete phase transition time is obtained, while this amount is 78% when considering the lowest and highest inlet temperatures. The geometric factor which is the aspect ratio has also affected the flow field and PC dynamics. Up to 78% reduction in the phase transition time is obtained at the highest aspect ratio. Further improvements in the performance are achieved by using nanoparticles in the base fluid. The amounts in the phase transition time reduction are 8% and 10.5% at aspect ratio of 0.5 and 1.5 at the highest nanoparticle concentration.

The thermofluid system and offered control mechanism for PC dynamics control can be considered for the design, optimization, further modeling and performance improvements of applications with PCM installed systems.

The purpose of this paper is to numerically study MHD natural convection and entropy generation of Al₂O₃-water alumina nanofluid inside of T-shaped baffled cavity which is subjected to a magnetic field.

Effect of various geometrical, fluid and flow factors such as aspect ratio of enclosure and baffle length, Rayleigh and Hartmann number of nanofluid have been considered in detail. The hydrodynamics and thermal indexes of nanofluid have been described using streamlines, isotherms and isentropic lines.

It is found that by enhancing Hartmann number, symmetrical streamlines gradually lose symmetry and their values decline. It is found that by enhancing Hartmann number, symmetrical streamlines gradually lose symmetry and their values decline. The interesting finding is an increase in the impact of Hartmann number on heat transfer indexes with augmenting Rayleigh number. However, with augmenting Rayleigh number and, thus, strengthening the buoyant forces, the efficacy of Hartmann number one, an index indicating the simultaneous impact of natural heat transfer to entropy generation increases. It is clearly seen that the efficacy of nanofluid on increased Nusselt number enhances with increasing aspect ratio of the enclosure. Based on the results, the Nusselt number generally enhances with the larger baffle length in the enclosure. Finally, with larger Hartmann number and lesser Nusselt one, entropy production is reduced.

The authors believe that all the results, both numerical and asymptotic, are original and have not been published elsewhere.

T-shaped cavities occur by design in many technical applications. An example of such a stator cavity is the side space between the guide vane carriers and the outer casing of a steam turbine. Thermal conditions inside it have a significant impact on the deformation of the turbine casing. In order to improve its prediction, the purpose of this paper is to provide a methodology to gain better knowledge of the local heat transfer at the cavity boundaries based on experimental results.

To determine the heat transfer coefficient distribution inside a model cavity with the help of a scaled generic test rig, an inverse heat conduction problem is posed and a method for solving such type of problems in the form of linear combinations of Trefftz functions is presented.

The results of the calculations are compared with another inverse method using first-order gradient optimization technique as well as with estimated values obtained with an analytic two-dimensional thermal network model, and they show an excellent agreement. The calculation procedure is proved to be numerically stable for different degrees of complexity of the sought boundary conditions.

This paper provides a universal and robust methodology for the fast direct determination of an arbitrary distribution of heat transfer coefficients based on material temperature measurements spread over the confining wall.

Thermo-magnetic convective flow analysis under the impact of thermal radiation for heat and entropy generation phenomena is an active research field for understanding the efficiency of thermodynamic systems in various engineering sectors. This study aims to examine the characteristics of convective heat transport and entropy generation within an inverted T-shaped porous enclosure saturated with a hybrid nanofluid under the influence of thermal radiation and magnetic field.

The mathematical model incorporates the Darcy-Forchheimer-Brinkmann model and considers thermal radiation in the energy balance equation. The complete mathematical model has been numerically simulated through the penalty finite element approach at varying values of flow parameters, such as Rayleigh number (Ra), Hartmann number (Ha), Darcy number (Da), radiation parameter (Rd) and porosity value (e). Furthermore, the graphical results for energy variation have been monitored through the energy-flux vector, whereas the entropy generation along with its individual components, namely, entropy generation due to heat transfer, fluid friction and magnetic field, are also presented. Furthermore, the results of the Bejan number for each component are also discussed in detail. Additionally, the concept of ecological coefficient of performance (ECOP) has also been included to analyse the thermal efficiency of the model.

The graphical analysis of results indicates that higher values of Ra, Da, e and Rd enhance the convective heat transport and entropy generation phenomena more rapidly. However, increasing Ha values have a detrimental effect due to the increasing impact of magnetic forces. Furthermore, the ECOP result suggests that the rising value of Da, e and Rd at smaller Ra show a maximum thermal efficiency of the mathematical model, which further declines as the Ra increases. Conversely, the thermal efficiency of the model improves with increasing Ha value, showing an opposite trend in ECOP.

Such complex porous enclosures have practical applications in engineering and science, including areas like solar power collectors, heat exchangers and electronic equipment. Furthermore, the present study of entropy generation would play a vital role in optimizing system performance, improving energy efficiency and promoting sustainable engineering practices during the natural convection process.

To the best of the authors’ knowledge, this study is the first ever attempted detailed investigation of heat transfer and entropy generation phenomena flow parameter ranges in an inverted T-shaped porous enclosure under a uniform magnetic field and thermal radiation.

The purpose of this paper is to study the natural convection and radiation heat transfer inside Nonagon inclined cavity with variable heated source length, which contains a porous medium saturated with nanofluid in the presence of uniform heat generation or absorption under the effect of uniform magnetic field with variable direction. The shape factor of nano particles is taking account for the model of nanofluid.

This study is established in two-dimensional space. The 2D numerical study is effectuated with Comsol Multiphysics based on the on the finite element method. The 2D equation system is exposed on dimensionless form taking into account the boundary conditions.

Results obtained show that the convection heat transfer is ameliorated with the augmentation of heated source length. The convection heat transfer is enhanced by increasing Rayleigh, Darcy numbers and the heated source length; however, it is reduced by rising Hartmann number. The presence of radiation parameter lead to improve the convection heat transfer in the presence of both uniform heat generation/absorption. The average Nusselt number reaches a maximum for an inclination of cavity γ = 45° and a minimum for γ = 60°. Both the increase of the shape factor of nano particles and the solid fraction of nano particles improve the convection heat transfer.

Different studies have been realized to study the heat transfer inside cavity contains porous medium saturated with nanofluid under magnetic field effect. In this work, the Nonagon geometric of cavity studied has never been studied. In addition, the effect of radiation parameter with relation of the shape factor of nanoparticles in the presence of uniform heat generation/absorption on the heat transfer performance have never been investigated. Also, the effect of magnetic field direction with relation of the inclination cavity on heat transfer performance.

The purpose of this paper is to examine numerically the magnetohydrodynamic (MHD) free convection and thermal radiation heat transfer of single walled carbon nanotubes-water nanofluid within T-inverted shaped corrugated cavity comprising porous media including uniform heat source/sink for solar energy power plants applications.

The two-dimensional numerical simulation is performed by drawing on Comsol Multiphysics program, based on the finite element process.

The important results obtained show that increasing numbers of Rayleigh and Darcy and the parameter of radiation enhance the flow of convection heat. Furthermore, by increasing the corrugation height, the convection flow increases, but it decreases with the multiplication of the corrugation height. The use of a flat cavity provides better output than a corrugated cavity.

The role of surface corrugation parameters on the efficiency of free convection and heat transfer of thermal radiation within the porous media containing the T-inverted corrugated cavity including uniform heat source/sink under the impact of Lorentz forces has never been explored. A contrast is also established between a flat cavity and a corrugated one.

The purpose of this paper is to perform numerical simulations based on the incompressible smoothed particle hydrodynamics (ISPH) method for thermo-diffusion convection in a hexagonal-shaped cavity saturated by a porous medium and suspended by a nano-encapsulated phase change material (NEPCM). Here, the solid particles are inserted into a phase change material to enhance its thermal performance.

Superellipse rotated shapes with variable lengths are embedded inside a hexagonal-shaped cavity. These inner shapes are rotated around their center by a uniform circular velocity and their conditions are positioned at high temperature and concentration. The controlling equations in a non-dimensional form were analyzed by using the ISPH method. At first, the validation of the ISPH results is performed. Afterward, the implications of a fusion temperature, lengths/types of the superellipse shapes, nanoparticles parameter and time parameter on the phase change heat transfer, isotherms, isoconcentration and streamlines were addressed.

The achieved simulations indicated that the excess in the length of an inner superellipse shape augments the temperature, concentration and maximum of the streamlines in a hexagonal-shaped cavity. The largest values of mean Nusselt number are attained at the inner rhombus shape with convex (n = 1.5) and the largest values of mean Sherwood number are attained at the inner rectangle shape with rounded corners (n = 4).

The ISPH method is developed to emulate the influences of the uniform rotation of the novel geometry shapes on heat/mass transport inside a hexagonal-shaped cavity suspended by NEPCM and saturated by porous media.

This paper aims to concentrate on the impacts of a discrete heat source location on heat transfer and entropy generation for a Ag-water nanofluid in an open inclined L-shaped cavity.

The governing partial differential equations for this study are computed by the finite volume method.

The results show that increasing the inclination angle leads to a rise in heat transfer. It is clear with the increase in the nanoparticles volume fraction that the thermal performance reduces, and it increases when the inclination angle increases.

Because of the continuous literature survey, the authors have not found a study that concentrates on the entropy generation in a wide variety of irregular ducts. Thus, in this paper, they present the analysis of entropy generation in an L-shaped duct experiencing a mixed convective flow with a nanofluid. The authors deal with this geometry because it is very useful in cooling systems of nuclear and chemical reactors and electronic components.

This paper aims to numerically investigate the magnetohydrodynamic (MHD) convection heat transfer of nanofluid inside a differentially heated enclosure with various fin morphologies.

The fluid flow within the cavity was governed by N-S equations while it within porous medium was solved by the non-Darcy model, called the Darcy–Forchheimer model based on representative element-averaging method. Empirical correlations from experimental data are used to evaluate the effective thermal conductivity and dynamic viscosity. Relevant governing parameters, including thermal Rayleigh number (10⁵-10⁷), Hartmann number (0-50), Darcy number (10⁻⁶-10⁻¹), thermal conductivity ratio of porous matrix (1-10³), nanoparticles volume fraction (0-0.04) and topology designs of porous fins, are sensitively varied to identify their effects and roles on the fluid flow and heat transfer. Particularly, heatlines are used to investigate the mechanism of heat transport.

Numerical results demonstrate that the predictions of average Nusselt number are augmented by using more porous fins with high permeability, and this effect becomes opposite in tiny Darcy numbers. Particularly, for high Darcy and Rayleigh numbers, the shortest fins could achieve the best performance of heat transfer. In addition, the prediction of average Nusselt number reduces with an increase in Hartmann numbers. An optimal nanoparticles concentration also exists to maximize heat transfer enhancement. Finally, numerical correlations for the average Nusselt number were proposed as functions of these governing parameters.

Present work could benefit the thermal design of electronic cooling and thermal carriers in nanofluid engineering.

Present work could benefit the thermal design of electronic cooling and thermal carriers in nanofluid engineering. In addition, optimum thermal removals could enhance the lifetime of electronics, therefore reducing the cost of energy and materials.

To the best knowledge of authors, there are not any studies considering the synergetic effects of porous fins on MHD convection of nanofluids. Present work could benefit the thermal design of electronic cooling and thermal carriers in nanofluid engineering.

The purpose of this paper is to investigate the effects of Ha and the Nanoparticles (NP) volume fraction over the irreversibility and heat transport in Darcy–Forchheimer nanofluid saturated lid-driven porous medium.

The present paper highlights entropy generation because of mixed convection for a lid-driven porous enclosure filled through a nanoliquid and submitted to a uniform magnetic field. The analysis is achieved using Darcy–Brinkman–Forchheimer technique. The set of partial differential equations governing the considered system was numerically solved using the finite element method.

The main observations are as follows. The results indicate that the movement of horizontal wall is an important factor for the entropy generation inside the porous cavity filled through Cu–water nanoliquid. The variation of the thermal entropy generation is linear through NPs volume fraction. The total entropy generation reduces when the Darcy, Hartmann and the nanoparticle volume fraction increase. The porous media and magnetic field effects reduce the total entropy generation.

Interest in studying thermal interactions by convective flow within a saturating porous medium has many fundamental considerations and has received extensive consideration in the literature because of its usefulness in a large variety of engineering applications, such as the energy storage and solar collectors, crystal growth, food processing, nuclear reactors and cooling of electronic devices, etc.

By examining the literature, the authors found that little attention has been paid to entropy generation encountered during convection of nanofluids. Hence, this work aims to numerically study entropy generation and heat transport in a lid-driven porous enclosure filled with a nanoliquid.