Alumina-water Nanofluid Research Articles

Casson Nanofluid Instability with Viscosity and Conductivity Variation Using Brinkman Model

The present work investigates the onset of convective instability of a non-Newtonian Casson nanofluid layer saturating a porous medium. Conductivity and viscosity are taken to be linear functions of nanoparticle volume fraction and Darcy-Brinkman model is used to modify the momentum equation. It is assumed that all the physical variables undergo a small disturbance on the basic solution and the normal mode technique is used to convert partial differential equations into ODE’s to get the expression of thermal Rayleigh number. Darcy parameter, non-Newtonian fluid property and conductivity variation parameter are coupled together leading to a significant increase in the stability of the layer. Numerical computations are carried out for various base fluids (water, oil, blood, glycol) under different porous phases (glass wool, limestone, sand) for metallic and non-metallic nanoparticles (copper, Iron, alumina, silicon oxide) using the software Wolfram Mathematica (version 12.0). The novelty of the work lies in the fact that the conductivity variation pattern for porous media is established as glass wool < limestone < sand and for base fluids as water < blood < glycol < oil. Maximum conductivity variation is observed for copper-oil nanofluid with sand as porous medium and glass saturated with alumina-water nanofluid shows the minimum variation. Oscillatory mode is found to dominate the instability state for bottom-heavy fluid layer. Darcy parameter stabilizes the fluid layer while porosity effects are destabilizing. Metals are found to be more stable as compare to non-metals.

Comparison of cooling performance of nanofluid flows in mini/micro-channel stacked double-layer heat sink and single-layer micro-channel heat sink

Mini/micro-channel heat sinks are the advanced cooling method to fulfill the cooling demand of electronic equipment integrated with high-power circuit packages. Many designs are provided to enhance the thermal performance of micro-channel. In the present experimental study, the mini/micro-channel stacked double-layer heat sink is designed and tested for the first time. The mini/micro-channel stacked double-layer heat sink is composed of a single-layer micro-channel heat sink stacked with a mini-channel heat sink. The pure water and alumina-water nanofluid are considered as the coolant. A comparison is conducted between the heat dissipation performance of mini/micro-channel stacked double-layer heat sink and single-layer micro-channel heat sink. The results showed that as compared with the case of single-layer micro-channel heat sink, the pressure drop can be reduced considerably by using the mini/micro-channel stacked double-layer heat sink. For the flow rate ratio less than 2.0, the average convection heat transfer coefficient of the mini/micro-channel stacked double-layer heat sink is higher than that of the single-layer micro-channel heat sink. Finally, the FOM ratios are greater than unity for all cases. This indicates that the use of mini/micro-channel stacked double-layer heat sinks has more advantages in engineering applications than the single-layer micro-channel heat sinks.

The impact of using a turbulator at the nanofluid flow inlet to cool a solar panel in the presence of phase change materials using artificial intelligence

Due to the importance of renewable energies in providing energy for the future of human beings, a simulation is performed in this paper on the nanofluid (NFD) flow inside a U-shaped tube placed under a solar panel (SPL). The tube is placed under the panel inside the enclosure containing phase change material (PCM). Alumina-water NFD and an organic PCM are used in this study. A turbulator (TBR) is utilized to improve the heat transfer (HTF) between the NFD flow and the SPL. This study is unsteady and is carried out at different Reynolds numbers (Res) to examine the effect of the TBR. The finite element method (FEM) is employed for the simulations and temperature-dependent relationships are used for the NFD flow. Finally, the best conditions are evaluated using artificial intelligence. The results of this study demonstrated that the use of a TBR causes the panel temperature (TPL) to reduce and the complete melting time of the PCM to enhance. The increment in Re entailed a reduction in the melting process of PCM and the TPL. The enhancement of Re increased the value of the HTF coefficient. Besides, the use of TBR enhanced the HTF coefficient. The minimum amounts of TPL and pressure drop correspond to the case when Re = 211 and the TBR is employed.

Various nanoparticle shapes and quadratic velocity impacts on entropy generation and MHD flow over a stretching sheet with joule heating

The purpose of this research was to examine the impact of NP shape on the entropy production of a water-alumina nanofluid over a permeable MHD stretching sheet at quadratic velocities with viscous dissipation and joule heating. The hot fluid is water-alumina nanofluid, which consists of four different NP shapes (brick, platelet, blade, and oblate spheroid), and the cool fluid is water itself. As a result of its exceptional ability to enhance heat transmission, Al2O3-H2O nanofluid is used extensively in industrial production. The governing PDEs are changed into a nonlinear differential system of coupled ODEs by a series of similarity transformations. The code, in MATLAB, is an effective version of the Runge-Kutta technique for obtaining numerical solutions. In the region behind a stretching sheet, the wall shear stress increases by almost 6.3% for increases in the volume fraction of nanoparticles from 0% to 2% and by 12.6% for increases from 0% to 4%. When the magnetic effect accounts for roughly 5 percent of the boundary layer flow, there is an approximately 16.4 percent increase in the rate of convective heat transfer. The frictional force and thermal entropy produced by nanofluids with blade-, brick-, and Os-shaped NPs was lower than that produced by nanofluids with platelet-shaped NPs. On the cold fluid side, the nanofluid with Os-shaped NPs develops thermal entropy at a faster rate than those with brick-, blade-, cylinder-, and platelet-shaped NPs.

Three-Dimensional Analysis of the Thermal Behavior of Alumina-Water Nanofluid Inside Hexagonal and Octagonal Enclosed Domain

The current work focused on the study of the laminar and steady free convection of Aluminum Oxide / Water nanofluid inside cavities. Two different cavities have the same volume but different overall surface area and count of walls are studied. These cavities are heated differentially on the vertical square side walls which of identical area and dimensions for both cavities. The other vertical walls of these cavities have hexagonal and octagonal shapes. The first cavity has eight walls while the second has ten walls. The study accomplished for solid particles volume fraction and Rayleigh number ranges of (φ = 0.01, 0.03, 0.05) and (103 ≤ Ra ≤ 106). The study interested highly by the effect of the cavity geometry parameters including the lateral cross section, the height, the number of walls on the flow and heat transfer. Other flow parameters are recognized on the fluid flow and heat transfer fields like the nanoparticles volume fraction and the Rayleigh number. The results indicated that the surface area increase by means the additional walls has an observed effect on guiding the results. Where the octagonal cavity has better enhancement in heat transfer especially at (Ra=104 and 105). The percent increase in Nu over the hexagonal cavity is (0.6, 0.8, 0.7, 0.3) for the specified Ra range.

Nanofluid flowing over a rotating disk that is stretching and permeable: An unsteady model

The model presented in this paper deals with the investigation of the unsteady laminar flow past a stretchable disk. The nanofluids Al2O3/H2O and Cu/H2O are considered for the analysis where the thermal characteristics and flow behavior of these nanofluids are compared. In addition, the system is subjected to the suction force that has significant impacts on velocity of the nanofluid flow. Further, the nanoparticle solid volume fraction is another important parameter that is discussed which has a prominent role on both profiles of the nanofluid. Furthermore, the investigated mathematical model is framed using PDEs that are transformed to ODEs using suitable transformations. The system of equations obtained in this regard is solved by employing the RKF-45 numerical method where the results are obtained in the form of graphs. Various nanofluids flow parameters arise in the study and the impact of all these parameters has been analyzed and interpreted. Some of the major outcomes are that the higher values of nanoparticle solid volume fraction enhance the temperature while it decreases velocity of the flow. The comparison of flow of the two nanofluids concluded that alumina–water nanofluid has a better velocity while the copper–water nanofluid has a better thermal conductivity.

Stability analysis of water-alumina nanofluid film at the spherical interface

The interface of a viscous fluid and [Formula: see text]-water nanofluid is analyzed through linear instability analysis in a spherical configuration. The viscous fluid lies inside the sphere while the outside region contains nanofluid. In this model, the viscosity of the nanofluid is considered a function of the base fluid viscosity, nanoparticles volume fraction, fractal aggregates, and nanoparticles shape. The perturbed flow is taken as irrotational, and the linear perturbation equations are solved through viscous irrotational theory. The perturbations growth rate can be computed through a 2-degree polynomial and the coefficients of this polynomial are the functions of the Atwood number, Richardson number, Weber number, Reynolds number, etc. The nanofluid interface is found more stable than the viscous fluid interface. The density of nanofluids raises the amplitude of disturbances while the nanofluid's viscosity has a reverse effect.

Radiative Blasius Hybrid Nanofluid Flow Over a Permeable Moving Surface with Convective Boundary Condition

The Blasius flow over a movable and permeable plate is envisaged in this study. Water-based hybrid nanofluid is incorporated with the insertion of thermal radiation, suction, and a convectively heated plate. The governing partial differential equations that simulate the fluid model are modified to ordinary differential equations through the implementation of self-similar transformation. A numerical solver known as bvp4c in Matlab is adopted to solve the problem numerically through the finite difference code with the Lobatto IIIa formula. Non-unique solutions are acquirable when the plate and the flow move in a dissimilar direction. As conducting the stability analysis, it is validated that the first solution is stable and reliable. The findings reveal that the imposition of stronger thermal radiation and greater Biot number for convection can lead to a better heat transfer performance. The 2% volume fraction of copper in the 1% volume fraction of alumina nanofluid composition would lead to greater skin friction when the plate is moving oppositely from the flow direction compared to the lesser volume fraction of copper. The boundary layer separation also can be efficiently prevented by composing a 2% copper volume fraction in the 1% alumina-water nanofluid compared to the lesser copper volume fraction.

Parametric study on a convective flow in a thermal storage using IBM/thermal lattice Boltzmann flux solver

One of the most popular topics in the field of engineering is natural convection due to its wide applications. Hence, the analysis of entropy production helps the researcher to design more efficient thermal systems. At this end, the present works tries to provide a comprehensive view on hydrodynamic, thermal and entropy production attitudes of free convection in a simplified thermal storage. The thermal storage is filled with alumina-water nanofluid. To solve the governing equations, the lattice Boltzmann method is employed and combined with Immersed Boundary Method. The immersed boundary method is applied to perform an accurate and effective numerical simulation of thermal flow in the curved boundaries. In the result section, the streamlines and temperature field are depicted. In addition, the contributions of entropy production are extracted graphically. The numerical results are gathered for various influential factors such as Rayleigh number (Ra in range of 103 to 106), alumina nanoparticle concentration 0≤wt%≤1 and aspect ratio of fins (AR in range of 0.200 to 0.588).

Pulsating multiple nano-jet impingement cooling system design by using different nanofluids for photovoltaic (PV) thermal management

The present work proposes a new cooling system for thermal management and cooling of photovoltaic (PV) systems. Pulsating flow with multiple jet impingement is considered by using different fluid types. Hybrid nanofluid and alumina–water nanofluid having cylindrical ans spherical shaped nanoparticles are used as the cooling medium. The study is conducted by using finite volume method for various values of pulsating amplitude (between 0 and 1), Strouhal number (between 0.01 and 1), solid volume fraction of nanoparticles (between 0 and 2%) and slot number of the impinging jet (between 1 and 13). It is observed that pulsating amplitude is more effective on the cooling performance enhancement as compared to frequency while average Nusselt number (Nu) rises by about 63.5% while temperature drop of 2.16 °C can be achieved when pulsation amplitude is increased from 0 to 1. Nanofluid with cylindrical shaped nanoparticles and hybrid nanofluid show very similar trends while temperature drop of 2.6 °C is achieved when cooling system with nanofluid-cylinder in pulsating flow case is compared with pure-fluid in non-pulsating flow configuration. When nanoparticles loading amount on the thermal improvement is compared, the most favorable cases are obtained for nanofluid-cylinder and hybrid nanofluid case. The average Nu increments become 3.5%, 22.8% and 22.9% for nanofluid-spherical, nanofluid-cylinder and hybrid nanofluid when lowest and highest nanoparticle loading amount cases are compared. Increasing the slot number in pulsating flow case significantly rises the Nu and drops the average panel surface temperature. When different systems are compared pulsating nano-jets cooling system using alumina–water nanofluid with cylindrical shaped nanoparticles provides the most effective cooling system while while temperature drop of ΔT=37.30 °C is achieved at the highest amplitude and highest loading of nanoparticles in the pure fluid as compared to uncooled PV system.

Numerical Analysis of the Effect of Nanoparticles Size and Shape on the Efficiency of a Micro Heatsink.

In this paper, two novel micro heat sinks (MHSs) were designed and subjected to thermal analysis using a numerical method. The fluid used was Boehmite alumina-water nanofluid (NFs) with high volume fractions (VOFs). Studies were conducted to determine the influence of a variety of nanoparticle (NP) shapes, such as platelet brick, blade, cylinder, and Os. The heatsink (HS) was made of copper, and the NFs entered it through the middle and exited via four outlets at the side of the HS. The finite element method was used to simulate the NFs flow and heat transfer in the HSs. For this purpose, Multi Physics COMSOL software was used. The maximum and middle values of HS temperature (T-MAX and T-Mid), thermal resistance (TH-R), heat transfer coefficient (h), FOM, etc., were studied for different NP shapes, and with Reynolds numbers (Re) of 300, 1000, and 1700, and VOFs of 0, 3, and 6%. One of the important outcomes of this work was the better thermal efficiency of the HS with rectangular fins. Moreover, it was discovered that a rise in Re increased the heat transfer. In general, adding NPs with high VOFs to MHSs is not appropriate in terms of heat. The Os shape was the best NP shape, and the platelet shape was the worst NP shape for high NPVOF. When NPs were added to an MHS, the temperature of the MHS dropped by an average of 2.8 or 2.19 K, depending on the form of the pin-fins contained inside the MHS (circular or square). The addition of NPs in the MHS with circular and square pin-fins enhanced the pressure drop by 13.5% and 13.3%, respectively, when the Re = 1700.

A forced convection of water aluminum oxide nanofluid flow and heat transfer study for a three dimensional annular with inner rotated cylinder

The article examines a water alumina nanofluid and heat transfer through the three-dimensional annular. The annular is constructed by the two concentric cylinders in which the inner cylinder can rotate along the tangential direction at a constant speed. A slip boundary condition will be imposed to vanish the viscous effect in the vicinity of the outer cylinder wall. Moreover, the rotating cylinder is kept at a hot temperature, and the outer one is at a cold temperature. A three-dimensional incompressible Navier Stokes and energy equations were carried in cylindrical coordinates. The simulation was observed using the emerging computational tool of COMSOL Multiphysics 5.6, which implements Least Square Galerkin's scheme of finite element method. The parametric study will be done by altering the speed of rotation of the inner cylinder from 1 to 4, volume fraction from 0.001 to 0.9, and the aspect ratio from 0.4 to 0.6 for a fixed Reynolds number of 35,000. The results will be displayed with graphs and tables for average values of the Nusselt number, the percentage change in the temperature, and the skin friction at the middle plan. It was found that the average Nusselt number at the middle of the annular increases before the volume fraction of 0.2 and then decreases for all values of the volume fraction for a fixed rotation of the inner cylinder. The average percentage change relative to the inner cylinder's hot temperature decreases with the volume fraction increase for the fixed rotation. Also, it was found that the quantity of nanoparticles in the domain is improving the average skin friction in the middle of the channel, and it can be reduced by improving the rotation of the inner cylinder by about 10–23% strictly depending upon the aspect ratio for a particular case.

Investigation into the use of phase change materials in thermal management of a solar panel in the vicinity of tubes with slotted rectangular fins

In this paper, a thermal solar panel is simulated numerically. An enclosure of CaCl2·6H2O phase change material (PCM) is placed at the bottom of the panel in the presence of graphene nanoparticles. A tube is placed in the middle of the enclosure in which alumina-water nanofluid flows at the Reynolds numbers of 200 to 800. A number of fins are installed on the tube. The effect of using three different types of fins in a period of 0 to 5 h and Reynolds number on the panel temperature, PCM volume percentage, output nanofluid temperature, bottom panel thermal resistance, and panel temperature uniformity is examined. The finite element method is employed to solve governing equations. The results demonstrate that the best temperature uniformity on the solar panel occurs at Reynolds number of 800. The Reynolds number of 800 also has the lowest maximum temperature, average panel temperature, and thermal resistance. Using the Reynolds number of 800 instead of 200 reduces the PCM volume percentage from 93.14% to 23.40% and reduces the nanofluid output temperature by 4.3 °C. Using fins case 3 creates the minimum temperature on the panel and minimum amount of thermal resistance. The fins case 3 and case 2 produce the minimum and maximum amounts of molten PCM.

The Forced Convection Analysis of Water Alumina Nanofluid Flow through a 3D Annulus with Rotating Cylinders via κ−ε Turbulence Model

We investigated the dynamics of nanofluid and heat transfer in a three-dimensional circular annular using the κ−ε turbulence model and energy equations. The pipe contained two concentric and rotating cylinders with a constant speed in the tangential direction. A heat flux boundary condition was executed at the inner cylinder of the annular. The pipe was settled vertically, and water alumina nanofluid was allowed to enter, with the initial velocity depending on the Reynolds number, ranging from 30,000 to 60,000. The volume fraction of the solid particles was tested from 0.001 to 0.1. The speed of the rotation of the cylinders was tested in the range from 0.5 to 3.5. The simulations were developed using COMSOL Multiphysics 5.6, adopting the finite element procedure for governing equations. The results were validated using the mesh independent study and the average Nusselt number correlations. We found that the average Nusselt number in the middle of the channel decreases linearly with the increase in the volume fraction of the water alumina nanofluid. The novelty of the present work is that various correlations between the average Nusselt number and volume fraction were determined by fixing the Reynolds number and the rotation of the inner cylinder. We also found that fixing the Reynolds number and the volume fraction improves the average Nusselt number at the outlet linearly. In addition, it was stated that the increase in the total mass of the nanofluid would decrease the average temperature at the outer cylinder of the annular. Moreover, the maximum average improvement percentage in the average Nusselt number, which is about 21%, was observed when the inner cylinder rotation was changed from 1.5 to 2.5 m/s.

Two-phase simulation of the generated entropy for the nanofluid flow inside a ribbed passage for cooling of a PV cell

• Introduce a new ribbed channel configuration with nanofluid for PV cooling. • The triangular-shaped rib demonstrates better performance. • Using the nanofluid reduces the thermal entropy generation about 65.1% • The overall irreversibility descends with nanofluid by increasing Reynolds number. Current work deals with the generated entropy of alumina–water nanofluid in a ribbed passage to cool the photovoltaic (PV) cell. The two-phase mixture approach is employed to model the nanofluid within a ribbed channel with discrete V-form and staggered rib roughness. The nanofluid is analysed at a concentration of 1%, and the outcomes are compared to pure water. This study focuses on the influences of the cross-section shape of the ribs. Four different shapes of the rib cross-section, including circular, elliptical, square, and triangular-shaped, are investigated in this paper. The results indicated that using the nanofluid rather than water considerably reduces the thermally generated entropy such that the highest reduction in this parameter is about 65.1%. Employing the ribbed channel demonstrates smaller thermal entropy by generating six intense cross-flows. The highest reduction in the thermally generated entropy rate is around 72.9% when the triangular-shaped rib is used. Besides, the positive influence of the nanofluid is about 2.3 times higher when the ribbed channel is utilised. The triangular-shaped rib demonstrates better performance and considerably contributes to the lower thermal irreversibility. The overall irreversibility descends when the nanofluid is used and by an increase of Reynolds number.

Magnetohydrodynamic mixed convection and entropy generation analysis of Al2O3-water nanofluid past a confined circular cylinder

Numerical simulations are carried out for transient magnetohydrodynamic mixed convective heat transfer of alumina–water nanofluid flow past an isothermal circular cylinder confined in an electrically insulated rectangular duct in the presence of a uniform transverse magnetic field. A control volume method is used to solve the governing equations on a nonuniform Cartesian grid, and the cylinder is imposed using the immersed boundary method. Numerical experiments are performed for a Reynolds number based on the cylinder diameter of ReD=200, blockage ratio of BR=0.2, Richardson numbers of (Ri=−1;0;2), nanoparticle volume fractions of (φ=0.0;0.1;0.2), and Hartmann numbers in the range 0≤Ha≤13. In this work, mean and instantaneous flow and thermal distributions are analyzed graphically, and their corresponding sensitivity to the nanoparticle volume fraction has been determined. Numerical predictions demonstrate the impact of buoyancy and magnetic parameters regarding the spatial development and shedding characteristics of the near wake, and we explore their potential use to selectively excite or suppress vortex shedding, augmentation of heat transfer, and entropy generation minimization in nanofluid flow. The results reported herein indicate that depending on the parametric set, linear and nonlinear flow response to magnetic excitation is observed with bifurcations between different states. The outcome of the study shows that vortex shedding is completely suppressed when a critical value of the Hartmann number is reached, and that the threshold value of the Hartmann number strongly depends on the value of the buoyancy parameter and nanoparticle volume fraction. Based on the entropy distributions, we show that for all values of the nanoparticle volume fraction and in the range of buoyancy and magnetic parameters considered in this work, the entropy generation is dominated by irreversibilities due to heat transfer and the relative contributions of entropy generation due to fluid friction and magnetic effect are not preponderate.

MHD stagnation-point flow of nanofluid due to a shrinking sheet with melting, viscous dissipation and Joule heating effects

Nanofluids have received a lot of interest in recent years because of their prospective uses in industrial applications; therefore, a progressive study on flow control is requirable. The primary goal of this study is to elucidate the magnetohydrodynamic (MHD) stagnation point flow of alumina-water nanofluid due to a shrinking sheet with the inclusion of viscous dissipation, melting and Joule heating effects. The similarity transformation reduces the complexity of the model into the similarity (ordinary) differential equations. The findings are numerically acquired by programming the resultant equations in MATLAB and processing them via the bvp4c tool. The findings show that at the shrinking condition, two solutions are conceivable, with the separation of the flow occurring within this area. The examination of stability reveals that only one solution remains stable, while the other is not. By boosting the melting effect and decreasing the nanoparticle volume fraction as well as the Eckert number, it is possible to accelerate the heat transmission in the fluid flow system. The temperature profile is decelerated as the nanoparticle volume fraction amplifies, and this is accompanied by a decrease in Joule heating. This study also suggests considering 2% of alumina volume fraction instead of 1% so that the flow separation process can be delayed, and simultaneously sustain the laminar flow. The increment of melting effect by 25%, reducing the skin friction approximately by 5% at a certain degree of shrinking. This study can be referred as guidance in managing the relevant parameters imposed on the nanofluid flow, which has the capability to give significant advantages, especially in monitoring the flow performance.

Viscous dissipation effect on forced convective transport of nanofluids in an asymmetrically heated parallel-plate microchannel

This study intends to investigate the effects of viscous dissipation on the Alumina-water nanofluids transport in an asymmetrically heated microchannel, accounting for Brownian motion and thermophoresis mechanism. An iterative algorithm deploying Runge-Kutta fourth order method was set up to solve the governing equations numerically. Viscous dissipation shifts the highest concentration and lowest fluid temperature away from the adiabatic wall and redistributes the spatial variation of thermal conductivity and viscosity, retarding the Nu as its effect strengthens. It is noteworthy that the trends of Nusselt number variation with an increasing nanoparticle bulk concentration, and Brownian and Themophoretic diffusivity ratio, N BT , highlight the competition between the enhanced thermal diffusion effect and the hindered heat convection by a larger flow resistance. A Brinkman number, Br larger than 0.02 alters the Nu pattern of variation with N BT . Viscous dissipation leads to more pronounced effects of particle migration on the concentration and temperature distribution in particular. Assuming negligible viscous dissipation, Nusselt number deteriorates beyond an Alumina concentration of 3.65 vol %. while Titania-water nanofluids showed an opposite trend. The total entropy generation, caused by fluid flow irreversibility predominantly, amplifies with an increasing nanoparticle concentration, more significantly when the concentration is below 6.5 vol %., for Br = 0.1. Conversely, an increase in Brownian to Thermophoretic diffusivity ratio, N BT , lessens the entropy generation.

Effect of simultaneous use of water-alumina nanofluid and phase change nanomaterial in a lithium-ion battery with a specific geometry connected solar system

This paper investigates numerically the thermal management of a lithium-ion (Li-iNB) battery connected to a solar system using the finite element method. The Li-iNB uses a combined cooling system (CLS), i.e. phase change nanomaterial (N-PCM) and nanofluids (NFs). A bionic geometry is used around the Li-iNB in the presence of PCM between the NFs flow channels. Water-alumina NFs and CaCl2_6H2O/Graphene N-PCM are used, and the NF flows through the N-PCMs and charges the N-PCMs. The results show that using N-PCM instead of simple N-PCM leads to the absorption of more heat from the Li-iNB. The use of nanoparticles (NPs) in the N-PCMs causes the volume percentage (VOP) of melted N-PCM to increase at the same time. The outlet temperature of the CLS is enhanced by adding NPs to the N-PCM and intensifying the inlet velocity of the NFs. An increment in the NFs velocity enhances the value of the Nu and reduces the average CLS temperature. The increase in velocity results in a better charge of the N-PCM, leading to more percentage of melting volumes of N-PCM. Finally, it is found that the use of a hybrid system of NFs-N-PCM improves the performance of the Li-iNB thermal management system.

Significance of Darcy-Forchheimer and Lorentz forces on radiative alumina-water nanofluid flows over a slippery curved geometry under multiple convective constraints: a renovated Buongiorno’s model with validated thermophysical correlations

Critical point of view on the dynamics of water conveying chemically reactive alumina nanoparticles around a slippery curved geometry (e.g. hemisphere) due to the linear stretching motion of the irregular boundary is inconclusive based on the fact that nothing is known on probable results when increasing the strength of the main embedded factors, like the nanoparticles’ loading, the curvature geometry index, the magnetic field, the nonlinear porosity of the medium, and the activation energy, in the case where the convective heating, the convective mass transport, and the velocity slip are imposed as boundary conditions. For a better description of the flow problem, Buongiorno’s and Koo-Kleinstreuer-Li’s approaches were adopted as realistic nanofluid models since the thermo-rheological features of alumina-water nanofluids are complex functions of many nanometric phenomena (e.g. Brownian motion, thermophoresis, and thermal resistance). Further, the nonlinear system of the governing partial differential equations (PDEs) that models the transport phenomenon was reduced mathematically to a system of ordinary differential equations (ODEs). To achieve convergent solutions, the obtained system of ODEs was solved numerically using irregular generalized differential quadrature schemes along with an efficient Newton–Raphson package. Based on the results of this analysis, it is worth concluding that the nanofluid motion is observed to be decelerated when the magnitudes of slip parameter and drag forces have increased, whereas an enhancing trend like for the thermal Biot number is witnessed for the temperature throughout the medium.