Search

AbstractThermal management of high-power electronic devices is essential to control their enormous heat generation, which is usually the cause of their damage. Scientists have found several solutions for cooling electronic devices, but a counter-current heat exchanger has never been used. In the same context, numerical research on the thermal performance of a proposed new cooling system based on a counterflow heat exchanger combined with a heat sink is conducted in this article. Cu-H2O nanofluid, n-Docosane nano-enhanced phase change material, and water were selected as coolants, and they are compared in terms of temperatures, Nusselt number, heat transfer coefficient, pressure drop, friction factor, and performance enhancement coefficient using a two-phase mixture transient model based on Finite Volume method. Two cases of the proposed system are studied to find the optimal distance between heat exchanger pipes and the hot surface. Results are compared with previous experimental data to demonstrate that the system under study is accurate. They revealed that integrating the heat exchanger with the heat sink using Cu-H2O nf as a coolant maintained the hot surface temperature below 308 K with improved heat transfer by 31.22% compared to water. 0.25 mm is the optimum distance to find the highest thermal performance of the cooling system. [ABSTRACT FROM AUTHOR]

The fractional of a time derivative for the incompressible smoothed particle hydrodynamics (ISPH) method is adopted to handle thermal radiation on thermosolutal convection in a porous cavity barred by nanoencapsulated phase change materials (NEPCMs). A novel work on the rotational velocities of two rods during thermosolutal convection of NEPCMs within a novel cavity of two connected circular cylinders is introduced. The management of heat-mass transfer and velocity magnitude inside distinct designed materials below various boundary conditions carries improvements for energy efficiency. The physical factors are thermal radiation Rd = 0 − 3 , Fusion temperature θ f = 0. 0 5 − 0. 8 , Rayleigh number Ra = 1 0 3 − 1 0 6 , hot source length L Hot = 0. 4 − 1 , Darcy number Da = 1 0 − 2 − 1 0 − 5 , and fractional order parameter α = 0. 9 5 − 1. This study reported the role of thermal/solutal conditions in varying the dual convection flow and heat capacity contour. The lower Da provides an elevated porous resistance which decelerates the nanofluid velocity. The fusion temperature alters a heat capacity contour. [ABSTRACT FROM AUTHOR]

This research attempts to study the thermal activity of suspension consisting of water and NEPCM elements inside a cavity with a trapezoidal cross-section. In addition, the cavity center contains a cold circular object rotating at a constant speed. The cavity is thermally characterized by the following: the upper and lower walls are thermally insulated (adiabatic), while the two lateral walls have a high temperature. The purpose of this study is to find out how the suspension interferes with the transfer of heat from hot walls to the cold body through the intervention of some initial conditions, which are: The effects of rotating cylinder speed (Re = 1 -500), medium permeability (Da = 10–5 – 10–2) and the magnetic field strength (Ha= 0 -100). The study used a digital simulation by solving the differential equations related to fluid mechanics and heat transfer using the Galerkin finite element (GFEM) method.to understand the influences of studied parameters (Re, Da and Ha numbers), the contours of isotherms, heat capacity and pathlines are presented in terms of these parameters. The findings indicated that as the rotation speed of the obstacle increased, the forced convection became dominant, and the thermal transmission rate improved. The improvement of the thermal transfer rate was also observed for higher Da numbers. Increasing the strength of the magnetic field hiders the fluid motion and reduces the thermal activity. At the highest studied Re, increasing Da from 10 to 5 to 10–2 augmented the Nusselt number by 10 times, while augmenting Ha from 0 to 100 reduced the Nu by 46 %.

The intensification of freezing rates through the incorporation of nano-sized powders and fins through a cold storage unit was examined. The Galerkin method with special meshing was utilized to solve equations, which were based on the supposition of conduction mode dominance. Additives of varying diameters (dp) and three different concentration levels (ϕ) were implemented. The findings are presented through ice front visualization, contour plots, and scalar curves. The computational code demonstrated high accuracy during the validation phase. The results reveal that as the dp increases, the solidification time initially drops by approximately 20 %, then subsequently increases by about 49.45 %. The optimal solidification time of 2951.17 s was achieved with medium-sized powders. Furthermore, an intensification in (ϕ) leads to a significant decrement in freezing time by about 41.43 %, with the most pronounced effect observed for nano-powders with dp = 40 nm.

Magnetohydrodynamic and entropy generation of double-diffusive mixed convection in a curvilinear cavity filled with nano-enhanced phase change material and a rotating cylinder has been studied in this paper. Three heat sources have been considered and a range of different variables such as Reynolds number (10 ≤ Re ≤ 100), Richardson number (0.1≤ Ri ≤ 10), Hartmann number (0≤ Ha ≤50) Lewis number (0.1≤ Le ≤ 0.9), bouncy ratio (1≤ Nz ≤ 5), fusion temperature (0.1≤ θf ≤0.9) and Stephan number (0.1≤ Ste ≤0.9). These variables have been numerically solved by applying the Finite Element Method. The main results indicated that heat transfer, mass transfer and heat capacity are hugely increased with the increase of the Re, Ri and volume concentration while decreasing with the increase of the Ha number and entropy generation. Furthermore, the melting/solidification region is hugely influenced by the fusion temperature while this variable has a negligible influence on streams, heat transfer and mass transfer. Furthermore, the value of the average Nusselt number and average Sherwood number has increased by 328 % and 258 % respectively by increasing the Reynolds number from 10 to 100. Also, these two numbers have decreased by 61 % and 54 % respectively by increasing the Hartmann number from 0 to 20.

Abstract This study discusses an evacuated tube collector-type solar water heater (ETCSWH) using a phase change material (PCM) chamber with fins, nanofluid, and nano-enhanced phase change material (NEPCM). First, the charging phenomena in a horizontal triplex tube heat exchanger (TTHX) equipped with fins, natural convection, and an ETCSWH system without PCM is simulated to validate the solution. The impact of adding fins and nanoparticles with a volume fraction of 3% of Al2O3 and Cu to paraffin wax and water-based fluid, respectively, on the unit's efficiency has been examined. The proposed system for the PCM melting process, heat storage, fluid flow behavior in the system, and velocity distribution and temperature contour in the storage tank and three parts of the absorber tube have been evaluated using ANSYS FLUENT software in a three-dimensional and transient simulation. The results show that Case 8 has improved by 39.7% compared to Case 1 and Case 4 by 5.2% compared to Case 1 within 4 h of the melting process. Also, Case 8 with a 43% and 6.4% shorter melting time than Cases 1 and 5 has the best performance and the greatest heat transfer rate. The productivity of the ETCSWH system is considerably enhanced by the use of fins, NEPCM, and nanofluid.

This study discusses an evacuated tube collector-type solar water heater (ETCSWH) using a phase change material (PCM) chamber with fins, nanofluid, and nano-enhanced phase change material (NEPCM). First, the charging phenomena in a horizontal triplex tube heat exchanger (TTHX) equipped with fins, natural convection, and an ETCSWH system without PCM is simulated to validate the solution. The impact of adding fins and nanoparticles with a volume fraction of 3% of Al2O3 and Cu to paraffin wax and water-based fluid, respectively, on the unit's efficiency has been examined. The proposed system for the PCM melting process, heat storage, fluid flow behavior in the system, and velocity distribution and temperature contour in the storage tank and three parts of the absorber tube have been evaluated using ANSYS FLUENT software in a three-dimensional and transient simulation. The results show that Case 8 has improved by 39.7% compared to Case 1 and Case 4 by 5.2% compared to Case 1 within 4 h of the melting process. Also, Case 8 with a 43% and 6.4% shorter melting time than Cases 1 and 5 has the best performance and the greatest heat transfer rate. The productivity of the ETCSWH system is considerably enhanced by the use of fins, NEPCM, and nanofluid. [ABSTRACT FROM AUTHOR]

This work simulates thermo-diffusion and diffusion-thermo on heat, mass transfer, and fluid flow of nano-encapsulated phase change materials (NEPCM) within a complex cavity. It is a novel study in handling the heat/mass transfer inside a highly complicated shape saturated by a partial layer porous medium. In addition, an artificial neural network (ANN) model is used in conjunction with the incompressible smoothed particle hydrodynamics (ISPH) simulation to forecast the mean Nusselt and Sherwood numbers ( N u − and S h − ). Heat and mass transfer, as well as thermo-diffusion effects, are useful in a variety of applications, including chemical engineering, material processing, and multifunctional heat exchangers. The ISPH method is used to solve the system of governing equations for the heat and mass transfer inside a complex cavity. The scales of pertinent parameters are fusion temperature θ f = 0.05 − 0.95 , Rayleigh number R a = 10 3 − 10 6 , buoyancy ratio parameter N = − 2 − 1 , Darcy number D a = 10 − 2 − 10 − 5 , Lewis number L e = 1 − 20 , Dufour number D u = 0 − 0.25 , and Soret number S r = 0 − 0.8 . Alterations of Rayleigh number are effective in enhancing the intensity of heat and mass transfer and velocity field of NEPCM within a complex cavity. The high complexity of a closed domain reduced the influences of Soret-Dufour numbers on heat and mass transfer especially at the steady state. The fusion temperature works well in adjusting the intensity and location of a heat capacity ratio inside a complex cavity. The presence of a porous layer in a cavity's center decreases the velocity field within a complex cavity at a reduction in Darcy number. The goal values of N u − and S h − for each data point are compared to those estimated by the ANN model. It is discovered that the ANN model's N u − and S h − values correspond completely with the target values. The exact harmony of the ANN model prediction values with the target values demonstrates that the developed ANN model can forecast the N u − and S h − values precisely. [ABSTRACT FROM AUTHOR]

In recent years, the rise of machine learning (ML) has prompted researchers to expand the datasets required for optimizing and designing thermal systems. Also, the development and widespread use of electric vehicles (EVs) have surged significantly. However, one of the major challenges associated with EVs is the efficient cooling of Lithium-ion batteries (LIBs). Therefore, the exploration of innovative cooling methods can contribute greatly to the rapidly growing electric vehicle industry. This study focused on investigating the impact of embedding a nickel porous medium around a single 38,120 LiFeO4 cell. To conduct the study, the LIB, along with the nickel porous medium, was placed inside a duct that received a flow of water and Nano-encapsulated phase change materials (NEPCMs). The results obtained from the study indicate that embedding nickel porous media around the LIB led to a significant decrease in the maximum temperature of LIB, more than 40 C, and a remarkable increase in pressure drop more than 100 times. Additionally, it was observed that the decrease in porosity from 1 to 0.97 had a more pronounced effect on pressure drop and the maximum temperature of the LIB's surface, compared to the decrease from 0.97 to 0.95.

To enhance system productivity, fins were incorporated into the container, and PCM (phase change material) infused with alumina nanoparticles was introduced. Mathematical modeling was employed to evaluate the current problem, with a specific focus on utilizing water as the PCM for achieving the fastest solidification process. The integration of fins, PCM, and nano-powders introduces a novel dimension to the research, providing unique insights into enhancing solidification processes. The surrounding cold walls of the container play a crucial role in solidification, primarily through conduction. The low speed of H2O allows its neglect in simulation. The developed mathematical model for this work comprises two equations. While considering larger powder sizes improves particle interaction, the negative impact of sedimentation diminishes conductivity. The addition of nanoparticles results in a 41.34 % enhancement in the solidification rate. Furthermore, altering the powder diameter from thirty to 40 nm reduces the completion time about 19.98 %, whereas an increase from 40 to 50 nm elevates it by about 49.37 %.

The study of natural convection and heat transfer in a trapezoidal cavity finds a wide range of technological applications including thermal energy storage systems, building ventilation/insulation, waste heat recovery, electronic device cooling, controlling PV panel temperature, energy conservation, exchangers, nuclear reactors, furnaces, glass production, food processing, and drying technologies. The purpose of the current study is to explore the entropy and natural convection of non-Newtonian nano-encapsulated phase change material (NEPCM) suspension in a saturated porous medium enshrouded in a trapezoid-shaped domain with three heated blocks fitted with the bottom surface. The novelty of the present work is the introduction of power-law (Ostwald-de Waele) model subject to NEPCM suspension in trapezoidal enclosure emplacing three heated fins at its bottom surface embedded in Brinkman-Forchheimer extended Darcy medium with variant porosity. The finite element method is implemented to solve the governing equations numerically. The important findings of the present study include streamlines, isotherms, velocities, and apparent viscosity enhance while entropy generation whittles down with rise in Darcy number. Entropy generation ameliorates by 519.16 % for low to high porosity of Brinkman-Forchheimer extended Darcy medium. The maximum apparent viscosity augments by 1441.24 % when power law index ameliorates.

This work simulates thermo-diffusion and diffusion-thermo on heat, mass transfer, and fluid flow of nano-encapsulated phase change materials (NEPCM) within a complex cavity. It is a novel study in handling the heat/mass transfer inside a highly complicated shape saturated by a partial layer porous medium. In addition, an artificial neural network (ANN) model is used in conjunction with the incompressible smoothed particle hydrodynamics (ISPH) simulation to forecast the mean Nusselt and Sherwood numbers ($ \stackrel{-}{Nu} $ and $ \stackrel{-}{Sh} $). Heat and mass transfer, as well as thermo-diffusion effects, are useful in a variety of applications, including chemical engineering, material processing, and multifunctional heat exchangers. The ISPH method is used to solve the system of governing equations for the heat and mass transfer inside a complex cavity. The scales of pertinent parameters are fusion temperature $ {\theta }_{f} = 0.05-0.95 $, Rayleigh number $ Ra = {10}^{3}-{10}^{6} $, buoyancy ratio parameter $ N = -2-1 $, Darcy number $ Da = {10}^{-2}-{10}^{-5} $, Lewis number $ Le = 1-20 $, Dufour number $ Du = 0-0.25 $, and Soret number $ Sr = 0-0.8 $. Alterations of Rayleigh number are effective in enhancing the intensity of heat and mass transfer and velocity field of NEPCM within a complex cavity. The high complexity of a closed domain reduced the influences of Soret-Dufour numbers on heat and mass transfer especially at the steady state. The fusion temperature works well in adjusting the intensity and location of a heat capacity ratio inside a complex cavity. The presence of a porous layer in a cavity's center decreases the velocity field within a complex cavity at a reduction in Darcy number. The goal values of $ \stackrel{-}{Nu} $ and $ \stackrel{-}{Sh} $ for each data point are compared to those estimated by the ANN model. It is discovered that the ANN model's $ \stackrel{-}{Nu} $ and $ \stackrel{-}{Sh} $ values correspond completely with the target values. The exact harmony of the ANN model prediction values with the target values demonstrates that the developed ANN model can forecast the $ \stackrel{-}{Nu} $ and $ \stackrel{-}{Sh} $ values precisely.

AbstractThis article investigates the bioconvection flow within a porous circular cylinder filled with oxytactic microorganisms and incorporating nano-encapsulated phase change materials (NEPCMs). The circular cylinder, equipped with T-fins, is situated within the cylinder’s domain. The governing equations are solved using the ISPH method based on a time-fractional derivative. An ISPH simulation, coupled with an artificial neural networks (ANN) model, is employed to predict the values of the average Nusselt number (Nu¯). Utilizing bioconvection flow within a porous circular cylinder containing oxytactic microorganisms and integrating NEPCMs presents opportunities for progress in thermal management, environmental engineering, energy storage, and materials science. During the conducted simulations, we have investigated the impacts of Darcy, Lewis, Peclet, Rayleigh, and bioconvection Rayleigh numbers on a range of parameters, encompassing isotherms, heat capacity ratio, concentration profiles of oxygen and microorganisms, velocity field, and Nu¯. The results obtained highlight the significant influence of changes in the inner cylinder’s radius and fin length on regulating the intensity of bioconvection flow and improving heat transfer within a cavity. Additionally, the fusion temperature causes a shift in the heat capacity ratio toward the heat sources located within the cavity. The velocity field decreases by 97.39% as the Darcy number decreases from 10−2 to 10−5 due to the challenges posed by porous media. Increasing the length of the T-fin enhances the cooling area, causing the isotherms to contract and altering the heat capacity ratio. In comparison to the target values, the ANN model demonstrates accurate prediction of Nu¯, bolstering confidence in its predictions. [ABSTRACT FROM AUTHOR]

The thermal properties of Octadecane vary due to the addition of copper oxide (CuO) nanoparticles. The synthesis of two nano‐enhanced phase change material (NEPCM) required the implementation of the two‐step method, using Octadecane as the base phase change material and CuO nanoparticles at 2.5 and 5.0 wt%. The experimental characterization determined the specific heat capacity, and thermal conductivity of the NEPCMs solid phase, including phase change enthalpy and temperature. These experimental results were then utilized for computational simulation of the thermal charging (solidification) and discharging (melting) processes of NEPCMs within a spherical enclosure, employing the ANSYS/Fluent software. The incorporation of CuO nanoparticles led to an increase in thermal conductivity while causing a decrease in specific heat capacity, enthalpy, and phase change temperature of Octadecane. The computational results revealed a reduction in the melting period and an improvement in the solidification of both NEPCMs. In terms of melting, the convective heat transfer coefficient increased by approximately 27.4% and 3.2% for the NEPCM at 2.5 and 5.0 wt% CuO, respectively. During the solidification process, the overall heat transfer coefficient experienced a significant increase of 43.8% and 59.8% for the NEPCM at 2.5 and 5.0 wt%, respectively. [ABSTRACT FROM AUTHOR]

Researchers always like to find way for improving the performance of system integrated with PCM. In this paper, the container was combined with fins and PCM was mixed with nanoparticles to obtain quicker discharging process. Two significant variables related to second technique are fraction of additives (ϕ) and their shapes (m). To involve these factors in equations, single phase formulation was applied. Low magnitude of velocity of liquid material in freezing leads to simplification of equations of this transient procedure. Galerkin method which was applied for this modeling has good accommodation with previous publication. As ϕ soars, the solidification time declines from 4802.97s to 4244.61s and 3738.37s when blade shape particles were applied. This means that adding additive can enhance the rate of process about 22.16%. Moreover, augmenting the shape factor to higher level causes time to drop about 5.7%. [ABSTRACT FROM AUTHOR]

Renewable energy sources play a pivotal role in global energy reserves, with solar energy standing out as a prominent option due to its cleanliness, abundance, and minimal emissions. The conversion of solar energy into electrical power is facilitated by Photovoltaic (PV) technology. However, the efficiency of PV systems could be improved by elevated temperatures, adversely affecting both efficiency and operational lifespan. In order to address this challenge, this study explores the integration of passive cooling systems by using Phase Change Materials (PCM), specifically focusing on the enhanced capabilities provided by nanoparticles, referred to as Nanoparticles Enhanced Phase Change Materials (NePCM). This investigation establishes a 50-watt peak (Wp) PV system as a passive cooling system, comparing its performance with and without PCM and NePCM. The study evaluates three materials: traditional paraffin PCM, NePCM-Al2O3, and NePCM-ZnO. Experimental results, obtained at an intensity of 1000 W/m2, are validated by using a PV-PCM panel temperature modeling approach. The findings indicate that NePCM-ZnO performs better in reducing the PV system's operating temperature, lowering it from 59.4 °C to 52.62 °C at 1000 W/m2 intensity. Compared to PV systems without passive cooling, the study reveals that implementing NePCM-ZnO as a passive coolant enhances maximum PV output power by 10.85 W and maximum PV efficiency by 3.08%. This improvement is attributed to the significant reduction in the maximum PV temperature by 6.78 °C, displaying the efficacy of NePCM-ZnO in optimizing the operational performance of PV systems. [ABSTRACT FROM AUTHOR]

A novel treatment of fractional-time derivative using the incompressible smoothed particle hydrodynamics (ISPH) method is introduced to simulate the bioconvection flow of nano-enhanced phase change materials (NEPCM) in a porous hexagonal cavity. The fractional-time derivative is based on the Caputo style, which reflects the fractional order behavior in complex systems. In this work, the circular rotation of the embedded four-pointed star and the motion of oxytactic microorganisms in a hexagonal cavity are conducted. Due to the significance of fractional derivatives in handling real physical problems with more flexibility than conventional derivatives, the present scheme of the ISPH method is developed to solve the fractional-time derivative of the bioconvection flow in a porous hexagonal cavity. This study implicates the variations of a fractional-time derivative, a parametric of an inner four-pointed star, and the pertinent physical parameters on the behavior of a bioconvection flow of a nanofluid in a hexagonal-cavity containing oxytactic microorganisms. The presence of microorganisms has a significant role in many biological, engineering, and medical phenomena. From the present numerical investigation, it is well mentioned that the computational time of the transient processes can be reduced by applying a fractional-time derivative. The variable sizes of an inner fourpointed star enhance the bioconvection flow in a hexagonal cavity. [ABSTRACT FROM AUTHOR]

Hot cylinders within the cavity can find diverse thermal applications, ranging from electronic devices and heat exchangers to solar systems, nuclear reactors, and the thermal design of passive cooling systems. Consequently, considering the use of phase change materials (PCM) close to hot cylinders emerges as a viable method for both cooling and storing thermal energy. In this work, two hot cylinders are arranged vertically and horizontally in the nano-enhanced phase change material (NePCM) trapezoidal enclosure with varying angles. The novelty of the current study lies in the fact that no prior research has explored the impact of hot cylinders arrangement on the melting process of a NePCM within a trapezoidal cavity, considering various inclination angles. The fixed grid, adaptive mesh refinement, and enthalpy-porosity method are used to model the melting flow. The numerical results indicate that the trapezoidal enclosure with vertically arranged hot cylinders exhibits better thermal performance than the other configuration. It is also found that the full melting time for both arrangements is minimum when the angle of the trapezoidal enclosure is γ=+40°. The reduction in full melting times for the vertical and horizontal arrangements of this angle are 25.3% and 29.6%, respectively, compared to the trapezoidal enclosure with γ=0.0°. Moreover, the NePCM with the graphite nanoplatelets (GNPs) of φ=1.0% has the shortest melting time for 0.0%≤φ≤3.0%. As future research, further exploration into the complexities of non-Newtonian NePCM flow can be pursued. Additionally, there is potential to explore modifying the cylinders' geometry into elliptical forms, encompassing a range of aspect ratios.

This article discusses the heat transfer characteristics of the mixed convection of NEPCM-fluid (Polyurethane/ Nonadecane dispersed in water) contained within a wavy-sided walls cavity. Mixed convection is caused by an adiabatic rotating cylinder located in the cavity center, while natural convection results from deferential heating of side walls. The upper and lower walls of the cavity are insulated. The Galerkin finite element method (GFEM) implemented in COMSOL CFD package is employed to solve the governing equations. The influence of the nanoparticles volume fraction (Ø = 0.02, and 0.05), cylinder radius (R = 0.05, 0.15, and 0.25), cylinder rotating speed (Ω = 100, −500, 500, and 1000), the dimensionless fusion temperature (θfu = 0.1, 0.25, and 0.5), wavy side walls undulation peaks number (N = 1 to 4) on the flow pattern and temperature field are presented. The results revealed that the heat transfer enhances by increasing the angular speed of the cylinder and its radius, also an enhancement in heat transfer is obtained by upgrading the volume fraction of NEPCM, however, it was noticed that for small cylinders, the counterclockwise rotation of the cylinder reduced the heat transfer rate as the rotation opposed the direction of natural heat convection. In addition, the waviness pattern has a specific impact on each case, for example, N = 4 denotes the best result for only the cases Ω = -500 or 500 when R = 0.25 and Ø = 0.05, while the heat transfer is negatively affected by increasing N for the other cases. On another hand, the impact of θfu on the heat transfer rate was found to be insignificant. Globally, at the biggest cylinder radius, higher Ø and highest angular speed an enhancement by more than 900 % can be achieved.

A novel treatment of fractional-time derivative using the incompressible smoothed particle hydrodynamics (ISPH) method is introduced to simulate the bioconvection flow of nano-enhanced phase change materials (NEPCM) in a porous hexagonal cavity. The fractional-time derivative is based on the Caputo style, which reflects the fractional order behavior in complex systems. In this work, the circular rotation of the embedded four-pointed star and the motion of oxytactic microorganisms in a hexagonal cavity are conducted. Due to the significance of fractional derivatives in handling real physical problems with more flexibility than conventional derivatives, the present scheme of the ISPH method is developed to solve the fractional-time derivative of the bioconvection flow in a porous hexagonal cavity. This study implicates the variations of a fractional-time derivative, a parametric of an inner four-pointed star, and the pertinent physical parameters on the behavior of a bioconvection flow of a nanofluid in a hexagonal-cavity containing oxytactic microorganisms. The presence of microorganisms has a significant role in many biological, engineering, and medical phenomena. From the present numerical investigation, it is well mentioned that the computational time of the transient processes can be reduced by applying a fractional-time derivative. The variable sizes of an inner four-pointed star enhance the bioconvection flow in a hexagonal cavity.

This paper adopts the incompressible smoothed particle hydrodynamics (ISPH) method for simulating the dual diffusion of nano-encapsulated phase change material (NEPCM) in an annulus. Here, the novelty is appearing in simulating the double diffusion of NEPCM within a novel complex shape composed from the paradigm of an annulus between two circular cylinders mounted on rectangles. The ISPH method solved the regulating equations of a physical problem. The scales of parameters are a fusion temperature θf(0.05≤θf≤0.95), buoyancy ratio 0≤N≤10, nanoparticle parameter 0.01≤φ≤0.05, a radius of a circular cylinder 0.1≤rc≤0.4, Darcy parameter 10-2≤Da≤10-5, and Rayleigh's number 103≤Ra≤106. The performed simulations showed that the different boundary conditions amongst an inner blockage and outer cavity walls are affecting the strength of concentration and temperature. The location of a phase change zone is varied according to the variations of variable boundary conditions and fusion temperature. The mean Nusselt and Sherwood numbers are improving under an enlargement in a radius of an internal circular cylinder, and Rayleigh numbers.

The current investigation deals numerically with a two-dimensional steady laminar flow natural convection heat transfer of a dilute suspension of a base fluid and suspension of Nano Encapsulated Phase Change Materials (NEPCMs) nanoparticles saturated inside an inclined square enclosure with a centered internal conducting square block with a ratio of 0.5. The enclosure inclination angle varies from 0° to 90° with increments of 15°, and block thermal conductivity to the host fluid has been chosen to be 0.2 and 5. The obtained results are in excellent agreement with those available in the literature for validation. The findings reveal that the heat transfer depends considerably on the inclination angle, block thermal conductivity ratio, and Stefan number for all considered ranges. The present results suggest that the average Nusselt number rate is notably enhanced as the inclination angle rises from 0° to 90° for thermal conductivity KR = 0.2 and KR = 5; this enhancement is more evident as the Rayleigh number is increased. The average Nusselt number improves by 5%, 153%, 558%, and 1120% for Rayleigh numbers of 103, 104, 105, and 106, respectively, when the inclination angle varies from 0° to 90° for a thermal conductivity ratio of 0.2. This improvement is somewhat reduced in the case of a thermal conductivity of 5, where the average Nusselt number grows by around 0.4%, 27%, 213%, and 537% for Rayleigh numbers 103, 104, 105, and 106, respectively. The higher value of the latent heat capacity of encapsulated particles enhances the heat transfer rate; the decreased Stefan number induces a notable improvement in the average Nusselt number. This enhancement is more evident as the inclination angle increases. The findings clearly show a considerable influence on the isotherms and heat capacity ratio distributions for all considered block thermal conductivities and Rayleigh numbers. [ABSTRACT FROM AUTHOR]

To attain a new system with a higher rate of freezing, two approaches were utilized in this paper namely: (1) loading alumina nanoparticles; (2) involving curved walls. The geometry has two cold surfaces and pure PCM is water. The convection role in this mechanism is very low and so the related terms have been neglected in modeling. By adding source term of freezing in energy equations and removing the advection terms, the final form of mathematical model will appear. Finite element method, by involving the implicit technique, has been selected for simulations and to increase the correctness of code, an adaptive grid has been utilized. For better description of efficacy of alumina nanoparticles, influences of size and amount of powders have been examined. As greater sizes are utilized, the period firstly decreases around 19.98% then it augments around 49.13%. Besides, the dispersion of powders results in 70.06% reduction in freezing time. [ABSTRACT FROM AUTHOR]

This paper adopts the incompressible smoothed particle hydrodynamics (ISPH) method for simulating the dual diffusion of nano-encapsulated phase change material (NEPCM) in an annulus. Here, the novelty is appearing in simulating the double diffusion of NEPCM within a novel complex shape composed from the paradigm of an annulus between two circular cylinders mounted on rectangles. The ISPH method solved the regulating equations of a physical problem. The scales of parameters are a fusion temperature θ f (0.05 ≤ θ f ≤ 0.95) , buoyancy ratio 0 ≤ N ≤ 10 , nanoparticle parameter 0.01 ≤ φ ≤ 0.05 , a radius of a circular cylinder 0.1 ≤ r c ≤ 0.4 , Darcy parameter 10 - 2 ≤ D a ≤ 10 - 5 , and Rayleigh's number 10 3 ≤ R a ≤ 10 6 . The performed simulations showed that the different boundary conditions amongst an inner blockage and outer cavity walls are affecting the strength of concentration and temperature. The location of a phase change zone is varied according to the variations of variable boundary conditions and fusion temperature. The mean Nusselt and Sherwood numbers are improving under an enlargement in a radius of an internal circular cylinder, and Rayleigh numbers. [ABSTRACT FROM AUTHOR]

Improving the performance of storage units is important for saving energy. An implicit approach has been combined with the adaptive grid in this modelling for the presentation of solidification inside the tank with a sinusoidal cold surface. Not only the implementation of curved will but also the inclusion of nanoparticles was assumed as a passive technique for expediting freezing. The scalars were extracted by the Galerkin approach. The formulation of nanomaterial features was done by considering uniform concentration inside the domain. Increasing the fraction of CuO can reduce the freezing time from 2211.13 to 1943.72 s and 1675.37 s if the blade shape is selected. The augmentation of shape factor and fraction of nanomaterial lead to the reduction of freezing time by about 6.98% and 24.23%, respectively. The results proved that ϕ has a stronger effect than other active parameters.

The incompressible smoothed particle hydrodynamics (ISPH) scheme is advanced to handle the conformable fractal differential equations of natural convection for a tall fin inside a cavity barred by nano encapsulated phase change material (NEPCM). The bottom circular cylinder is occupied by a porous medium plus a nanofluid, while the upper circular cylinder is filled by a nanofluid only. The conformable fractal operators generalize the classic idea of differentiability and allow for the generation of new and universal rates of variation. So, the study's novelty is revealing the validity of these operators in creating a new environment to look for more extended natural convection systems. The pertinent parameters are dimensionless time parameter τ(0-0.325), Rayleigh number Ra(103-106), Darcy parameter Da(10-2-10-5), cold source length LCold0.5-2.5, Stefan parameter Ste0.2-0.8, conformable fractal parameter α(0.93-1), and fusion temperature θf(0.05-0.95). The main outcomes showed the responsibility of α in speeding up the phase change process and the transition procedure of the convection flow. The nanofluid speed is reduced in the porous layer of a cavity, especially at the lower Darcy parameter. Different thermal conditions are altering the phase change material and strength of isotherms within a cavity.

Utilizing one triangular cold wall and one wavy adiabatic wall creates new container which is utilized in current modeling research. Inside the container is filled with water and to improve the solidification rate, nano-powders were added into PCM with low concentration. Unsteady process of freezing inside the domain was simulated based on Galerkin method and empirical data were utilized for verification. Concentration of nano-powder and its size were assumed as variables. Homogeneous formulation for NEPCM was utilized to involve the nanoparticle effects in governing equations. This process is mainly supported by conduction and existence of cold region at bottom side makes the impact of buoyancy negligible. With augmenting the concentration of copper oxide, the conductivity augments and speed of solid front increases and lower time needs for full freezing process. Size of nano-powders can affect the process because of its effect of feature of NEPCM. With rise of dp, at first the conduction increases but further increment makes conduction becomes weaker due to sedimentation. When dp = 40 nm, increase of φ leads to reduction of time about 18.04%. With augment of dp from 30 for 40 and then 50 nm, the freezing time at first decreases about 20.01$ and then it augments about 35.48%. When φ = 0.04, dp = 40 nm, the fast process occurs and full solidification takes place after 457.60 s. [ABSTRACT FROM AUTHOR]

A numerical investigation of the magnetohydrodynamics of a mixed convection of nano-enhanced phase change material (NEPCM) within a triangular chamber containing an elliptical heat source is presented in this article. The forced convection has resulted from the movement of the upper cavity, while the free convection is due to the temperature difference between the heat source and cold inclined sidewalls. Four cases are considered based on the directions of the moving of the upper wall parts, namely, Case 1, where the left part is moving in the positive direction of the X -axis and the right part moves in the opposite direction (1(+−)), Case 2, where the two parts move in the positive direction of the X -axis (2(++)), Case 3, where the two parts move in the negative direction of the X -axis (3(− −)), and Case 4, where the left part moves in the negative direction of the X -axis and the right part moves in the negative direction (4(−+)). The Galerkin finite element method (GFEM) is employed for addressing the governing equations of the system under study. The impacts of the Reynolds number (1 ≤ R e ≤ 100) , the inclination angle of the elliptic heat source (0 ≤ γ ≤ 90) , the nanoparticles volume fraction ϕ   (0 % ≤ ϕ ≤ 8 %) and the movement directions of the parts of the upper wall (four cases) are presented and discussed. The results suggested that increasing Re enhanced the heat transfer rate, while increasing Ha reduced it. The vertical positions of the elliptical heat source resulted in the maximum heat transmission rate. At the highest Re, changing the location of the heat source from horizontal ( γ = 0 ) to vertical ( γ = 90 ) enhanced the average Nusselt number by 60%, while choosing Case 1 for upper wall movement increased the average Nusselt number by 300% compared to Cases 2 and 3. [ABSTRACT FROM AUTHOR]

Using the potential of nature's phenomena such as free convection phenomenon could help to cooling a piece, such as a moving hot plate in lid-driven problems. Moreover, adding modern nanostructures named nano-encapsulated phase change material (NEPCM) with ability of phase transition could greatly improve the heat transfer processes. In this study, the mixed convection of ethylene glycol (EG) and NEPCM was simulated inside a lid-driven cavity with a rotating cylinder to evaluate the contribution of Grashof number, cylinder speed, and concentration of NEPCM on the heat transfer characteristics. Hence, the findings of current numerical study indicated that the NEPCM with 6% concentration increased the mean Nusselt number by 41.7%. Moreover, the cylinder speed enhanced the mean Nusselt number by 38.7%. Finally, there was an optimum value for concentration occurred in 4% brought for Grashof number of 104.

Domestic water heating accounts for 15% to 27% of the total energy consumption in buildings in Australia. Over the past two decades, the latent heat thermal energy storage (LHTES) system has been widely investigated as a way to reduce fossil fuel consumption and increase the share of renewable energy in solar water heating. However, the research has concentrated on the geometric optimisation of the LHTES heat exchanger for the past few years, and this might not be sufficient for commercialisation. Moreover, recent review papers mainly discussed the development of a particular heat-transfer improvement technique. This paper presents perspectives on various solar hot water systems using LHTES to shift focus to on-demand performance studies, as well as structure optimisation studies for faster commercialisation. Future challenges are also discussed. Since the topic is an active area of research, this paper focuses on references that showcase the overall performance of LHTES-assisted solar hot water systems and cannot include all published work in the discussion. This perspective paper provides directional insights to researchers for developing an energy-efficient solar hot water system using LHTES. [ABSTRACT FROM AUTHOR]

This research paper describes the experimental investigation of the phase change characteristics of deionized (DI) water with the addition of functionalized graphene nanoplatelets (FGNP) in a spherical container used in cool thermal energy storage (CTES) systems. The nano-enhanced phase change materials (NEPCMs) are developed by the dissolution of FGNP in the mass concentrations of 0.25%, 0.50%, and 0.75% with DI water. The thermal conductivity (TC) and phase change enthalpy (H) of the NEPCMs were measured experimentally using the transient hot-wire method and DSC 214 polymer, respectively. At heat transfer fluid (HTF) temperatures of −10°C and 15°C, the mass fraction of 0.75 improves thermal conductivity by 48.2% and 33.2% in the solid and liquid phases, respectively. At a heating rate of 1K min-1, the addition of FGNP significantly reduces the H of the base PCM in both crystallization and melting processes. The maximum reduction in crystallization and melting time was recorded to be 32.4% and 52.4% in a spherical container with the addition of maximum concentration of FGNP at the HTF temperatures of −8°C and 25°C, respectively. [ABSTRACT FROM AUTHOR]

The incompressible smoothed particle hydrodynamics (ISPH) scheme is advanced to handle the conformable fractal differential equations of natural convection for a tall fin inside a cavity barred by nano encapsulated phase change material (NEPCM). The bottom circular cylinder is occupied by a porous medium plus a nanofluid, while the upper circular cylinder is filled by a nanofluid only. The conformable fractal operators generalize the classic idea of differentiability and allow for the generation of new and universal rates of variation. So, the study's novelty is revealing the validity of these operators in creating a new environment to look for more extended natural convection systems. The pertinent parameters are dimensionless time parameter τ (0 - 0.325) , Rayleigh number Ra (10 3 - 10 6) , Darcy parameter Da (10 - 2 - 10 - 5) , cold source length L Cold 0.5 - 2.5 , Stefan parameter S t e 0.2 - 0.8 , conformable fractal parameter α (0.93 - 1) , and fusion temperature θ f (0.05 - 0.95). The main outcomes showed the responsibility of α in speeding up the phase change process and the transition procedure of the convection flow. The nanofluid speed is reduced in the porous layer of a cavity, especially at the lower Darcy parameter. Different thermal conditions are altering the phase change material and strength of isotherms within a cavity. [ABSTRACT FROM AUTHOR]

In this work, the simulations of fractional-time derivative systems of natural convection in a porous annulus suspended by NEPCM under the magnetic field and thermal radiation influences are conducted by the ISPH method. The annulus is constructed amongst the exterior horizontal wavy cavity and interior horizontal wavy blockage. Here, the novelty is appearing in simulating the powers of a magnetic field on natural convection in a novel shape of an annulus between two horizontal wavy shapes. The outer vertical sides are kept at Th and the flat sides are adiabatic. The inner wavy blockage is kept at Tc with zero velocities. The fractional time-derivative, nanoparticle parameter, dimensionless time parameter, Darcy parameter, Hartmann number, thermal radiation parameter, Rayleigh number effects on the heat transfer within an annulus are examined. The outcomes revealed that the contributions of the time-fractional derivative are appearing well at the initial time step. Increasing nanoparticle concentration to 5% shrinks the nanofluid flow. The heat capacity is affected by the differences in the thermal radiation parameter. The thermal radiation parameter is enhancing the mean Nusselt number and diminishes the nanofluid flow in an annulus. The extra Rayleigh number boosts the temperature strength and nanofluid velocity within an annulus.

In a magnetic field, two-dimensional (2D) mixed convection is investigated within a zigzagged trapezoidal chamber. The lower side of the trapezoidal chamber is irregular, in particular, a zigzagged wall with different zigzag numbers N. The fluid particles move in the room due to the motion of the upper wall, while the porosity-enthalpy approach represents the melting process. The thermal parameters of the fluid are enhanced by what is called a nano-encapsulated phase change material (NEPCM) consisting of polyurethane as the shell and a nonadecane as the core, while water is used as the base fluid. In order to treat the governing equations, the well-known Galerkin finite element method (GFEM) is applied. In addition, the heat transfer (HT) irreversibility and the fluid friction (FF) irreversibility are compared in terms of the average Bejan number. The main results show that the melt band curve behaves parabolically at smaller values of Reynolds number (Re) and larger values of Hartmann number (Ha). Moreover, minimizing the wave number is better in order to obtain a higher heat transfer rate. [ABSTRACT FROM AUTHOR]

The natural convection of NEPCM was delivered in the closed cavity constructed from two circular cylinders. The contributions of the NEPCM particles in heat transfer are achieved by the phase change. The partial differential equations that govern a nanofluid motion and heat transport are solved by a time fractional derivative of ISPH method. The impacts of the pertinent parameters, thermal radiation parameter R d = 0 − 3 , Rayleigh number R a = 10 3 − 10 6 , Darcy parameter D a = 10 − 2 − 10 − 5 , Fusion temperature θ f = 0.05 − 0.8 , length of a hot source L Hot = 0.4 − 1 , and fractional time-derivative α = 0.95 − 1 on the nanofluid flow and heat transfer are discussed. The main findings indicated that the Rayleigh number is representing a well role in improving the nanofluid movements and intensity of the temperature within the two circular cylinders. The phase change zone is reducing by an increase in Rayleigh number. The higher nanofluid speed and heat transfer are higher at the top cylinder compared to the bottom cylinder. Increasing the length of a hot source enhances the temperature strength within a cavity. [ABSTRACT FROM AUTHOR]

Natural convection and melting of ice as a phase change material dispersed with copper nanoparticles are numerically investigated. Square cavity filled with nano‐mixture (Cu−ice) subjected to sinusoidal temperature distributions from the hot bottom boundary. The phase change process and heat transfer are formulated and solved using the enthalpy‐based lattice Boltzmann method. Home‐built numerical code is developed and validated. The effect of Rayleigh number (Ra = 104, 105, and 106) and copper nanoparticle concentration (ϕ = 0%, 1%, 3%, and 5%) on the flow characteristics and thermal performance of NePCM during the melting process is examined. According to the numerical results, the melting and charging times decrease by increasing the Rayleigh number. It is also observed that increasing the volume fraction of nanoparticle decrease melting time by up to 10%. [ABSTRACT FROM AUTHOR]

Energy saving has always been a topic of great interest. The usage of nano-enhanced phase change material NePCM is one of the energy-saving methods that has gained increasing interest. In the current report, we intend to simulate the natural convection flow of NePCM inside an inverse T-shaped enclosure. The complex nature of the flow results from the following factors: the enclosure contains a hot trapezoidal fin on the bottom wall, the enclosure is saturated with pours media, and it is exposed to a magnetic field. The governing equations of the studied system are numerically addressed by the higher order Galerkin finite element method (GFEM). The impacts of the Darcy number (Da = 10−2–10−5), Rayleigh number (Ra = 103–106), nanoparticle volume fraction (φ = 0–0.08), and Hartmann number (Ha = 0–100) are analyzed. The results indicate that both local and average Nusselt numbers were considerably affected by Ra and Da values, while the influence of other parameters was negligible. Increasing Ra (increasing buoyancy force) from 103 to 106 enhanced the maximum average Nusselt number by 740%, while increasing Da (increasing the permeability) from 10−5 to 10−2 enhanced both the maximum average Nusselt number and the maximum local Nusselt number by the same rate (360%). [ABSTRACT FROM AUTHOR]

The new code has been developed for simulating the freezing of nanomaterial with water base PCM. This code was based on Galerkin approach and style of grid depends on position of solid first layer. The two surfaces have been maintained at cold temperature and fins have been mounted to increase the space of cold area. The single phase techniques for deriving the properties of nanomaterial were developed. As powders were applied, the needed time augments from maximum value (1390s) to minimum value (11038.49s). This means that with selecting the powders with shape factor of 8.6, the freezing time declines about 25.28%. Besides, changing shape can reduce the time about 6.27%. As fraction increases to twice value, the speed of process increases around 12.93%.

A numerical investigation of the magnetohydrodynamics of a mixed convection of nano-enhanced phase change material (NEPCM) within a triangular chamber containing an elliptical heat source is presented in this article. The forced convection has resulted from the movement of the upper cavity, while the free convection is due to the temperature difference between the heat source and cold inclined sidewalls. Four cases are considered based on the directions of the moving of the upper wall parts, namely, Case 1, where the left part is moving in the positive direction of the X-axis and the right part moves in the opposite direction (1(+−)), Case 2, where the two parts move in the positive direction of the X-axis (2(++)), Case 3, where the two parts move in the negative direction of the X-axis (3(− −)), and Case 4, where the left part moves in the negative direction of the X-axis and the right part moves in the negative direction (4(−+)). The Galerkin finite element method (GFEM) is employed for addressing the governing equations of the system under study. The impacts of the Reynolds number (1≤Re≤100), the inclination angle of the elliptic heat source (0≤γ≤90), the nanoparticles volume fraction ϕ (0%≤ϕ≤8%) and the movement directions of the parts of the upper wall (four cases) are presented and discussed. The results suggested that increasing Re enhanced the heat transfer rate, while increasing Ha reduced it. The vertical positions of the elliptical heat source resulted in the maximum heat transmission rate. At the highest Re, changing the location of the heat source from horizontal (γ=0) to vertical (γ=90) enhanced the average Nusselt number by 60%, while choosing Case 1 for upper wall movement increased the average Nusselt number by 300% compared to Cases 2 and 3.

Control of heat transfer and fluid flow by using different shaped materials for different forces and boundary conditions brings advantages for energy efficiency. The present study is examined the effects of the thermal radiation on Magnetohydrodynamic (MHD) thermosolutal convection of Nano-Enhanced Phase Change Materials (NEPCMs) suspension in a horizontal wavy porous cavity with embedded high-temperature crescents. Using these types of heaters in a NEPCM under radiation and the magnetic field is the main novelty of this work. The Incompressible Smoothed Particle Hydrodynamics (ISPH) method established on a time-fractional derivative is employed to manage the suggested problem. The main simulations revealed that the alteration of a thermal radiation parameter changes the phase change material and enhances the nanofluid flow. The time-fractional derivative is playing a good role in reaching the steady-state and affecting the phase change material at the initial time steps. The movements of a NEPCM are reduced by an increment in the Hartmann number, time-fractional derivative, and solid volume fraction. The nanofluid speed decreases by 26.32% as α increases from 0.95 to 1.

The present work deals with thermal energy storage behavior of the nano-enhanced phase change materials (NEPCMs) for building space cooling application. The NEPCMs have been prepared using Deionized (DI) water as the base phase change material (PCM) and multi-walled carbon nanotubes (MWCNTs) as nanomaterial with mass concentration of 0.25%, 0.5%, and 0.75%. For better stability of additive materials in the base PCM, sodium dodecyl-benzene sulfonate (SDBS) has been chosen as an additive element. The sub-cooling of the DI water has been completely eliminated for a mass concentration of 0.75% of MWCNT. The differential scanning calorimetry(DSC) analysis has been conducted to measure the phase transition properties of NEPCMs. The enhancements of 12.8% and 14.13% in latent heat values for charging and discharging processes, respectively, were observed for maximum mass concentration. It has also been observed that the onset temperature for charging is reduced from − 12.8 to − 9.7 °C for NEPCM with maximum concentration. The maximum thermal conductivity (k) augmentation of 23% (solid phase) and 11.2% (liquid phase) has been achieved by the NEPCM having a mass concentration of 0.75% MWCNT at − 10 °C and 15 °C, respectively. According to the study results the reductions in total charging times are 28% and 19% with the NEPCM holding a mass concentration of 0.75% MWCNT for − 8 °C and − 6 °C heat transfer fluid (HTF) temperatures, respectively. The environmental pollution remediation can be achieved by the reduction in energy input to the chiller by minimizing the total time taken for the charging the PCM. [ABSTRACT FROM AUTHOR]

Improving the performance of storage units is important for saving energy. An implicit approach has been combined with the adaptive grid in this modelling for the presentation of solidification inside the tank with a sinusoidal cold surface. Not only the implementation of curved will but also the inclusion of nanoparticles was assumed as a passive technique for expediting freezing. The scalars were extracted by the Galerkin approach. The formulation of nanomaterial features was done by considering uniform concentration inside the domain. Increasing the fraction of CuO can reduce the freezing time from 2211.13 to 1943.72 s and 1675.37 s if the blade shape is selected. The augmentation of shape factor and fraction of nanomaterial lead to the reduction of freezing time by about 6.98% and 24.23%, respectively. The results proved that ϕ has a stronger effect than other active parameters. [ABSTRACT FROM AUTHOR]

Domestic water heating accounts for 15% to 27% of the total energy consumption in buildings in Australia. Over the past two decades, the latent heat thermal energy storage (LHTES) system has been widely investigated as a way to reduce fossil fuel consumption and increase the share of renewable energy in solar water heating. However, the research has concentrated on the geometric optimisation of the LHTES heat exchanger for the past few years, and this might not be sufficient for commercialisation. Moreover, recent review papers mainly discussed the development of a particular heat-transfer improvement technique. This paper presents perspectives on various solar hot water systems using LHTES to shift focus to on-demand performance studies, as well as structure optimisation studies for faster commercialisation. Future challenges are also discussed. Since the topic is an active area of research, this paper focuses on references that showcase the overall performance of LHTES-assisted solar hot water systems and cannot include all published work in the discussion. This perspective paper provides directional insights to researchers for developing an energy-efficient solar hot water system using LHTES.

This paper discusses the magnetic powers on the thermosolutal convection of nano-encapsulated phase change material (NEPCM) inside a porous annulus by using the ISPH method. A novel annulus is constructed between an exterior hexagonal-shaped and inner shape of the dual curves having varying lengths (a&b). The heat/mass source is put in the left-top and right-bottom parts of a hexagonal-shaped and the other parts are adiabatic. The inner dual curves are maintained at Tc and Cc. The effects of the inner dual curve lengths (a=0.1−0.4&b=0.2−1), a fusion temperature (θf=0.05−0.95), Darcy parameter (Da=10−2−10−5), Hartmann number (Ha=0−100), solid volume fraction (ϕ=0.01−0.06), time parameter (τ=0−0.8), and Rayleigh number (Ra=103−106) on the contours of heat capacity, concentration, streamlines, temperature, and nanofluid velocity are researched. The results revealed that an increase in a fusion temperature shifts a phase change zone from the dual curves towards the heater source positions. The lengths of the inner dual curves are controlling the contours of the heat capacity, temperature, streamlines, and concentration in an annulus. Thus, the velocity's maximum boosts by 26.92% as length b shrinks from 1 to 0.2. Increasing Ra expands the contours of temperature, concentration, and heat capacity Cr across an annulus.

• Second law scrutiny of NEPCM suspension inside a circular cylinder is inspected. • The cold circular cylinder possesses a wavy baffle which acts as a heater. • The amplitude of hot wavy baffle have a potential to be changed. • The whole system is assumed to be affected by Cattaneochristov heat flux model. • The governing equations have been solved via the finite element method (FEM). Free convection and second law scrutiny of nano-encapsulated phase change material (NEPCM) suspension along with entropy production inside a circular cold cylinder involving a wavy hot baffle is a significant thermal management aspect subject to various industrial applications. Phase change material (PCM) undergoes a solid-liquid phase mutation at a particular fusion temperature, and absorbs/releases an appreciable amount of energy because of the latent heat of phase mutation. Hence, NEPCMs would be prospective owing to their capability to enhance the working liquids' performance, keeping the system at a particular cooling temperature. In order to simulatethe free convection along with entropy generation of NEPCMs inside a circular cold cylinder entails a wavy hot baffle under CattaneoChristov heat flux model(Altered Fourier theory) and magnetic field, the finite element method (FEM) could be utilized to solve the governing equations. In this study, the amplitude of baffle could be changeable while its undulation number is fixed at 2. Amplifying Raylegh number intensifies streamlines, isotherms, horizontal and vertical velocities, total entropy generation whittles down local Bejan number. Higher magnetic field strength is responsible for slow movement of NEPCMs and augments local Bejan number. Growth of baffle size yields squeezes the streamlines, horizontal and vertical velocities and intensified tilted isotherms. [Display omitted] [ABSTRACT FROM AUTHOR]