Nanofluid Heat Transfer Research Articles

MHD nanofluid flow and heat transfer caused by a stretching sheet that is heated convectively: An approximate solution using ADM

The investigation detailed in this paper explores the behavior of a slippery nanofluid flowing over a permeable stretched sheet under the influence of magnetohydrodynamic forces, considering factors like thermal radiation, viscous dissipation, and convective boundary conditions. The analysis systematically establishes principles for conserving mass, heat, momentum, and nanoparticle concentration, deriving a set of nonlinear ordinary differential equations from the governing partial differential equations. To tackle these challenges, the Adomian decomposition approach is utilized as a central element of the solution methodology. Graphical representations are employed to depict the solutions across various physical parameters. Despite the significance of nanofluids in both industrial and scientific contexts, there exists a noticeable research gap concerning the combined impacts of thermal radiation, viscous dissipation, and convective boundary conditions on heat and mass transfer, especially when coupled with a permeable linear rough stretched sheet. This study aims to fill this void by offering quantitative insights into these intricate phenomena, thereby enhancing our understanding of nanofluid dynamics and their practical implications. The findings indicate that increasing slip velocity and magnetic parameters reduce the boundary layer thickness of the velocity profile but increase it for the temperature profile, suggesting a nuanced interplay between slip velocity and magnetic effects on velocity boundary layers, while the temperature boundary layer exhibits distinct thermal dynamics within the system.

Modeling of artificial neural network to analyze heat and mass transfer of ternary hybrid nanofluid between two parallel plates with inclined magnetic field

The applications of the artificial neural network (ANN) have become the focus of interest of researchers due to their convenience for accurate modeling, simulation, and efficiency of evaluation. The primary objective of this study is to investigate the characteristics of heat and mass transfer of the ternary hybrid nanofluid flow (THNF), which is squeezed between two parallel plates, using ANN. The plate which lies on x-axis is stretching while the upper plate (UP) can move in upward and downward direction. An inclined magnetic field (MF) is also applied to the lower plate (LP). A system of partial differential equations of flow, energy, and mass transfer is used to simulate the THNF, which is then condensed using similarity substitution to a collection of ordinary differential equations (ODEs). Using the differential transform method (DTM), the resultant nonlinear ODEs in dimensionless form are further solved. The influence of the different varying physical parameters on velocity, temperature, and concentration is graphically presented and discussed. It becomes apparent that the velocity, heat, and mass transfer in squeezing flows are significantly impacted by the inclination angle of the applied MF. To demonstrate the validity of the study, the numerical findings of the Nusselt and the Sherwood numbers are provided. For the accuracy of the used approach, DTM results are compared with results from the numerical approach. The novelty of the current work is to train the neural network with the Levenberg–Marquardt algorithm in the model. To get the estimated output of the model, different scenarios are set for training, testing, and validation. The analysis is done by mean square error (MSE), histogram, fitness curve, and regression (RG). The created ANN model is shown to be reliable due to its exceptional accuracy throughout the training, validation, and testing stages.

Enhanced heat transfer and thermal storage performance of molten K2CO3 by ZnO nanoparticles: A molecular dynamics study

Molten salt serves as a popular medium for thermal storage and transfer in concentrated solar power (CSP) systems. The existing experimental studies have found the capacity of enhancing the heat storage property of the molten carbonate by doping ZnO nanoparticles. However, it has been rarely reported to conduct simulations of ZnO/molten carbonate nanofluids, and the underlying mechanism of how ZnO nanoparticles enhance the heat transfer and storage capacity has less been explored. In this study, molecular dynamics (MD) simulation has been used to investigate the heat transfer and storage properties of a molten K2CO3 nanofluid containing ZnO nanoparticles. It was found that as the nanoparticle mass ratio in molten salt based nanofluids rises, their specific heat capacity initially increases but subsequently diminishes. The specific heat capacity peaks when the ZnO mass ratio is at 1 wt%, resulting in an increase of 17.83 % compared with the base salt. The thermal conductivity in nanofluids based on molten salt increases with the increasing of ZnO mass ratio. Multi-perspective analysis of the mechanism how ZnO nanoparticles enhance the thermal energy storage performance of molten salt, including the microstructural analysis, number density, vibrational density of state, and heat flow decomposition, is conducted. In addition, results of the number density illustrates that a compressed layer of K+ is formed surrounding the ZnO nanoparticles, and the change in the potential energy leads to an increasing heat capacity. Analysis of the heat flow decomposition suggests that the enhanced nonbonded interaction is the main reason for the improvement of thermal conductive performance in the nanofluids based on molten salt. The findings in the present study provide a new perspective of how ZnO nanoparticles enhance the thermophysical properties of molten salts.

Microgravity analysis of periodic oscillations of heat and mass transfer of Darcy-Forchheimer nanofluid along radiating stretching surface with Joule heating effects

Reduced gravity impact on mixed convection flow plays a significant role for designing of electric-generating plants in space, unwanted effects of free convection, thermodynamic stability, space devices, surface tension and movement of nanoparticles. The novelty of present work is to find the impact of reduced gravity, Joule heating and thermal radiations on Darcy Forchheimer magnetized flow of nanofluid along the stretching porous sheet. The variable gravity is assumed as temperature dependent with maximum density and maximum density. The governing model is converted into convenient model to find physical thermo parameters. The primitive steady, real and imaginary equations are formed by using stokes and primitive transformations. To make programming algorithm in FORTRAN Lahey-90/95, the primitively terms are deduced in each equation. For tabular and numerical findings of steady velocity, temperature and concentration, the implicit form of finite difference approach is applied with Gaussian elimination method. The fluctuating skin friction, fluctuating heat transfer and fluctuating mass transfer are displayed by using steady outcomes in main formula. It is found that the magnitude of fluid velocity enhances as magnetic force, reduced gravity and Darcy Forchheimer parameter enhances. It is concluded that temperature distribution decreases as magnetic force enhances. It is noted that oscillating frequency in skin friction and heat transfer enhances as Schmidt number enhances. It is found that the maximum fluctuating layer in heat and mass transfer enhances as Prandtl number enhances.

Effect of Wavy Interface on Natural Convection in Square Cavity Partially Filled with Nanofluid and Porous Medium using Buongiorno Model

nvective heat transfer improvement from wavy surfaces presents a new solution in industrial engineering for composite materials, including porous medium, and nanofluids to address the wavy irregular surfaces in heat transfer devices such as a wavy solar collector, energy absorption and filtration, thermal insulation, and geothermal power plants. This technique enables the performance of engineering applications. The numerical study is performed to examine the effects of a wavy interface separating two layers in the enclosure on heat exchange rates. This paper investigates numerically the natural convection flow in a square cavity partially filled with nanofluid-porous layers separated by a wavy horizontal interface. The left and right walls of the cavity are maintained at constant hot and cold temperatures, whereas the other walls are adiabatic. The Buongiorno model is used to describe nanofluid motion, taking into account the brownian and thermophoresis effects in the cavity. The Galerkin finite element method was applied to solve the differential governing equations. The dynamic, thermal field and heat transfer have been analyzed for various parameters such as Rayleigh number (10^3 ≤ Ra ≤ 10^6), the amplitude of interface (0 ≤ A ≤ 0.1), and undulation number (0 ≤ n ≤ 9). The results reveal that the flow intensity induced by buoyancy forces is more significant in the nanofluid layer than in the porous layer, since the heat transfer is enhanced while the flow is not sensitive to variations in amplitude and number undulation, and accordingly, the decline of average Nusselt and Sherwood numbers is insignificant. The effects of controlled parameters on the structure of nanofluid flow, heat, and mass transfer rate are insignificant.

Novel Numerical Investigations of Some Problems Based on the Darcy–Forchheimer Model and Heat Transfer

In this study, we introduced a new type of basis function and subsequently a Chebyshev delta shaped collocation method (CDSC). We then use this method to numerically investigate both the natural convective flow and heat transfer of nanofluids in a vertical rectangular duct on the basis of a Darcy–Brinkman–Forchheimer model and the electroosmosis-modulated Darcy–Forchheimer flow of Casson nanofluid over stretching sheets with Newtonian heating problems. The approximate solution is represented in terms of Chebyshev delta shaped basis functions. Novel error estimates for interpolating polynomials are derived. Computational experiments were carried out to corroborate the theoretical results and to compare the present method with the existing Chebyshev pseudospectral method. To demonstrate our proposed approach, we also compared the numerical solutions with analytic solutions of the Poisson equation. Computer simulations show that the proposed method is computationally cheap, fast, and spectrally accurate and more importantly the obtained approximate solution can easily be used by researchers in this field.

Numerical Computational of Chemically Reactive Hybrid Nanofluids with Melting Phenomena Passing Through a Disk: Comparative Study

This paper aims to investigate the solutions for the axisymmetric flow and heat transfer coming from a permeable disk in hybrid nanofluids. The nanofluids are under the influence of thermal radiation and contain magnetohydrodynamics and melting phenomena. For this, the momentum and temperature mathematical model is developed to investigate the axisymmetric flow of two-dimensional hybrid nanofluids, containing nanoparticles and a base fluid. Using appropriate similarity variables, nonlinear partial differential equations have been transformed into ordinary differential equations. These are further solved using the function bvp4c, which is built into MATLAB software. The physical behavior of parameters is discussed for the values on the basis of visuals and tables. The analysis further shows an increase in the local Nusselt number and skin frictional coefficient due to nonlinear thermal radiation and magnetic parameters. The results may be promising for the applications of hybrid nanofluids in heat transfer and cooling systems of all modern industries. The authors have confidence in their study due to the novelty of the results and underline the numerous practical utilities of hybrid nanofluids.

The Lattice Boltzmann Simulation of Free Convection Heat Transfer of a Carbon-Nanotube Nanofluid in a Triangular Cavity with a Solar Heater

In this paper, the flow and free convection heat transfer of a multi-walled carbon nanotube/water nanofluid in a triangular cavity with a solar heater is studied using the lattice Boltzmann method. The side walls of the cavity are cold and the bottom wall is partially heated by a solar heater, which have a non-uniform temperature distribution. It is assumed that the heating energy is provided by an absorber that is directly exposed to sunlight. Because of the limited variations of density, the Boussinesq approximation is used, which causes the coupling of hydrodynamic and thermal fields. For velocity and temperature distribution functions, a lattice Boltzmann model with two dimensions and nine directions is adopted. The effect of parameters, such as the Rayleigh number, the volume fraction of nanoparticles, and the position of solar heater, on the flow and heat fields is studied. The results show that, for all Rayleigh numbers studied, the Nusselt number increases as nanoparticles volume fraction increases. The addition of 4% nanoparticles causes the average Nusselt number to increase about 11% at low (Ra = 103) and moderate (Ra = 104) Rayleigh numbers and 217% at the high Rayleigh number (Ra = 105). Furthermore, it is shown that for a fixed Rayleigh number, heat transfer can be optimized by adjusting solar heater’s position. This study can provide a useful insight for utilizing solar heaters with non-uniform temperature distribution in triangular cavities.

Comparative Study of Convective Oldroyd-B Nanofluid and Hybrid Nanofluid Flow, Heat and Mass Transfer Analysis Over Stretching Sheet with Cattaneo-Christov Heat Flux Model

The current analysis appraises the flow, heat and mass transfer characteristics of Oldroyd-B nanofluids SWCNT-Water and hybrid nanofluids SWCNT/MWCNT-Water over the stretching sheet. Thermal radiation, modified Fourier heat flux and convective boundary conditions are also used to evaluate the flow. Graphs are used to compare the characteristics of nanofluid SWCNT-Water and hybrid nanofluid SWCNT/MWCNT-Water nanofluids in terms of concentration, temperature, and velocity. The flow mechanism is modelled in the form of nonlinear system of partial differential equation. These PDEs are converted into Ordinary differential equations by using the similarity variable techniques. The Finite Element Method is pre-owned to solve the obtained ODEs. Plots are used to show the results of temperature, concentration and velocity for both nanofluids for various values of the relevant parameters. The dimensionless skin friction coefficient, Nusselt number and Sherwood number values are scrutinized and revealed in tabular form. The important findings of this study reveal that the scattering of temperature and concentration of both SWCNT-Water nanofluid and SWCNT/MWCNT-Water hybrid OBF nanofluid elevates with amplifying values of thermal retardation parameter. With increasing values of the power low index number the sketches of temperature and velocity are both attenuate in the fluid region.

Optimizing heat transfer with nano additives: A mathematical approach

This study is carried out to investigate heat transfer of hybrid nanofluid between two concentric cylinders using the fractional Maxwell model. The fractional model is solved numerically; fractional derivatives are integrated using the L1 algorithm of Caputo derivative and the integer order derivatives are discretized using the Crank–Nicolson numerical method. The findings show that skin friction decreases when the relaxation time parameter increases. The thermal performance of the working fluid increased up to 5% when hybrid nanoparticles were suspended to it.

Retraction notice: Investigation of laminar fluid flow and heat transfer of nanofluid in trapezoidal microchannel with different aspect ratios

Retraction notice: Investigation of laminar fluid flow and heat transfer of nanofluid in trapezoidal microchannel with different aspect ratios

Thermal convective transport of nanofluids in a microannulus under electromagnetohydrodynamic and time-periodic pressure gradient

The study of the unsteady flow and heat transfer characteristics of nanofluids in microannulus is crucial for the optimal design and precise operation of microfluidic systems, and microfluidic technology has an important application value in microelectronic engineering. In this article, a theoretical analysis of the heat transfer characteristics of unsteady flow of Water-Al2O3 nanofluids through a microannulus under the coupling of an alternating electric field, a magnetic field, and a time-periodic pressure gradient is presented. Both the thermally completely developed flow assumption and the Debye–Hückel linear approximation are taken into consideration. The microannulus wall is subjected to a consistent heat flow while taking into account the effects of Joule heating and viscous dissipation. A semi-analytical solution of the temperature field is efficiently obtained using the Green’s function method. In addition, the Nusselt number and total entropy generation are further analyzed. The results show that the nanoparticle volume fraction and dimensionless frequency have a significant effect on the heat transfer characteristics of nanofluids. The increase of dimensionless frequency decreases the convective heat transfer and improves the cooling performance of microannulus. On the contrary, increasing the nanoparticle volume fraction improves the heat transfer performance of microannulus. Therefore, the results of this study can be used for electronic cooling of compact and micro-sized circuits. This study is instructive for unsteady flow and heat transfer of nanofluids in microchannels.

Expression of concern for article entitled “Numerical analysis of pressure drop and heat transfer of a non-Newtonian nanofluids in a Li-ion battery thermal management system (BTMS) using bionic geometries”

Expression of concern for article entitled “Numerical analysis of pressure drop and heat transfer of a non-Newtonian nanofluids in a Li-ion battery thermal management system (BTMS) using bionic geometries”

The Impact of Volume Fraction and Nanoparticles in the Flow of Nanofluids along the Boundary Layer Over a Flat Plate

Introduction: The forced convective, steady, viscous, nonlinear boundary layer flow of a two-dimensional problem over a flat plate with heat transfer nanofluids. The flow is laminar. Two different types of nanoparticles, namely, Titanium dioxide () and Silver are used to prepare nanofluids with base fluid is chosen as water. Nanofluids has a large number of applications in the area of biomedical, cooling and tribological applications. Objectives: To study about the effect different nanoparticles and their volume fraction in the flow of nanofluids along the boundary layer over a flat plate. Analyse the changes in the viscosity, density, specific heat capacity, thermal conductivity, Prandtl number, skin friction coefficient and Nusselt number. Methods: The flow of the fluid that are governed by the PDEs that are nonlinear are transformed into the ODEs that are nonlinear by employing similarity transformations, which then solved by the use of MATLAB bvp5c solution procedure. Results: Both thermal conductivity and heat transfer coefficient increases with the increase in the volume fraction of the corresponding nanoparticle. Also, Silver-water nanofluid has the high thermal conductivity and heat transfer rate when compared with Titanium dioxide-water nanofluid. Conclusions: Silver water nanofluid surpasses titanium dioxide water nanofluid in terms of thermal conductivity and heat transfer rate. Moreover, the physical attributes like viscosity, density, and thermal conductivity of nanofluids escalate proportionally with the volume fraction of nanoparticles. Conversely, specific heat capacity and Prandtl number exhibit an inverse relationship with the volume fraction of nanoparticles, decreasing as it increases.

Study of heat transfer in trihybrid nanofluid (Cu/Ag/Al2O3 with H2O) in Hele-Shaw cell and square enclosure with throughflow

The stability analysis of trihybrid nanofluid (Cu/Ag/ A l 2 O 3 as nanoparticles and H 2 O as base fluids) with spherical, brick, and cylindrical shapes, respectively, are examined theoretically and analytically with throughflow. Normal mode techniques have been used for linear stability analysis, and truncated Fourier series is carried out for nonlinear analysis. Comparison of Hele-Shaw cell and Square enclosure is performed in both linear and nonlinear analysis. Square enclosures are found to prevail in heat and mass transfer. Hele-Shaw number (HS number) has destabilizing behavior. Increase in concentration of nanoparticle increases the heat and mass transfer. Cylindrical shapes particles are found to have earlier rate of convection in both the system. Furthermore, throughflow exhibits destabilizing behavior. Hele-Shaw cell prevail heat and mass transfer on comparing for regular fluid. In all the three phases Prandtl number enhances the heat/mass transfer due to increase in momentum diffusivity of the fluid.

Numerical analysis of electrothermoconvection of a dielectric nanofluid in a heated cavity

A numerical analysis of electrohydrodynamic (EHD) flow and heat transfer of nanofluid in a heated rectangular cavity is presented. A two-dimensional (2D) rectangular cavity heated from the bottom is considered. An electric potential difference is applied vertically, with the bottom wall acting as a high-voltage electrode, and the top wall is grounded. TiO2-25 # transformer oil nanofluid with nanoparticle volume fraction ranging from 0–5% is considered. The numerical model for EHD flow and heat transfer of nanofluid is implemented in the finite-volume method (FVM) based numerical framework of OpenFOAM. A single-phase approach based on the effective properties is adopted to model the nanofluids. A two-way coupled EHD flow model is employed to consider mutual interactions of flow and electric field variables. The flow and heat transfer behavior of nanofluids in the presence of an electric field is quantified with reference to the key parameters, electric Rayleigh number (T), and the nanoparticle volume fraction ϕ. The addition of nanoparticles increased the viscosity and marginally reduced the natural convective flow and heat transfer. However, EHD flow induced by the electric field aided in overcoming the weak natural convection flow in nanofluids. Results confirm that nanofluids’ net effective heat transfer rates are notably increased in the presence of the electric field. For the parameters under consideration, combining electric fields with nanofluids led to a significant heat transfer enhancement of up to 32.3%. The present study showcases the feasibility of combining passive heat transfer enhancement using nanoparticles and active heat transfer enhancement using EHD flow.

Spectral quasi-linearization approach for the swimming of motile microorganisms on the bio-convection Casson nanofluid flow over a rotating circular disk

The ability of motile microorganisms is used to design of biomedical nanofluidic devices that utilize for targeted drug delivery, to influence heat transfer in nanofluids that are applied to the optimization of cooling system, in biotechnological processes where precise control over fluid flow, etc. However, based upon the several facts, the current investigation lead to propose the heat transfer characteristic of motile microorganisms swimming in a flow of bio-convection nanofluid over a rotating circular disk. The proposed study explores the impacts of dissipative heat generated by the movement of microorganisms, thermal radiation, and chemical reactions. The impact of cross-diffusive property organized by the implementation of Brownian motion and thermophorsis energies the flow phenomena of bio-convection. The set of coupled nonlinear system of non-dimensional equations is obtained by the implementation of similarity rules and further quasi-linearization method is utilized for the solution of this system. The characteristics of diversified parameters are presented through graphs with the variation of the proposed factors within their certain limitations and thee discuss briefly. Further, the important outcomes of the study are presented as; the fluid velocity decelerates due to the enhanced non-Newtonian Casson parameter, whereas the radiating heat for the inclusion of thermal radiation and coupling parameter, that is, Eckert number boosts up the heat transport phenomena.

Analytical Solution for MHD Casson Nanofluid Flow and Heat Transfer due to Stretching Sheet in Porous Medium

The feature of having a surface that can stretch has garnered attention in numerous industrial and engineering fields because of its advantages. Nevertheless, most fluid mechanics simulations for stretchable surfaces have predominantly relied on numerical solutions, with a notable lack of theoretical investigations into this matter. Consequently, the current research aims to contribute a theoretical exploration of heat transfer and boundary layer flow for Casson nanofluid on a linearly stretching sheet, considering the existence of porosity and magnetic field effects. Two distinct types of water-based nanofluids containing aluminium oxide and silicon dioxide are examined. By employing similarity transformations, the governing momentum and energy equations undergo transformation and subsequent analytical resolution using Laplace transformations. The resulting solutions are graphically presented to examine the influence of key parameters on temperature and velocity distribution. The analysis indicates that heat transfer is improved by the inclusion of nanoparticles, porosity, and a magnetic field. However, the velocity distribution slows down as a result of higher nanoparticle volume fraction, porosity, and magnetic field imposition.

Numerical simulation of combined convection and radiation heat transfer in a hybrid nanofluid inside an open fins cavity under a magnetic field

Numerical simulation of combined convection and radiation heat transfer in a hybrid nanofluid inside an open fins cavity under a magnetic field

Legendre wavelet integration operational matrix method for the numerical solution of unsteady MHD nanofluid flow between moving parallel plates

This study proposes a novel method based on Legendre wavelet integration operational matrix for solving a system of nonlinear ODE’s to model the two-phase, unsteady nanofluid flow and heat transfer between parallel plates in presence of magnetic field. To validate the applicability of proposed method, system of nonlinear BVP with exact solutions is employed as a test problem. Test problem results are compared with exact solution, and other numerical methods. The governing equations were then changed using similarity transformation into a set of nonlinear ODE’s. . Following this, the LWOMM is applied for the proposed problem. Findings demonstrated that, for a constant Reynolds number, skin friction coefficient value increases with rising Hartmann and squeezing numbers. Furthermore, it is demonstrated that Eckert number is a reducing function of the squeeze number and Nusselt number is an increasing function of Hartmann number.