Convection Heat Transfer Of Nanofluid Research Articles

Sinusoidal heating on convective heat transfer of nanofluid under differential technique

AbstractSinusoidal convection describes a smooth and repetitive heat transfer oscillation that reasonably calculates the optimal heat transfer for nanoparticle's intermolecular interactions. This study aims to investigate the heat transfer effects of Stokes second problem on the performance of novel fractional differential operators based on rheological characteristics of nanofluid. For the sake of augmentation in thermal characteristics of the nanofluid, the fractionalized governing equations based on the suspension of nanoparticles namely copper and silver in ethylene‐glycol have been developed. The fractional Stokes second problem is simulated with the help of transformation techniques and statistical data analysis. The analytic optimization of mathematical solutions of velocity and temperature have been established in terms of newly defined different Mittag‐Leffler functions. The statistical data for velocity field is generated by varying Hartman number, Prandtl number and Eckert number. The comparative analysis for two types of fractional differential operators of temperature distribution is perceived through bar column label, three‐dimensional color pie chart, three‐dimensional color map surface with projection, three‐dimensional bars and linear fitting of data. The comparative results revealed that temperature distribution has a significant effect and great influence on the stability of nanofluid by the embedded parameters.

Statistical and numerical analysis of magnetic field effects on laminar natural convection heat transfer of nanofluid in a hexagonal cavity

This paper presents a statistical and numerical investigation that examines the optimization and sensitivity analysis of the unsteady laminar natural convective heat transfer flow of Fe3O4-water nanofluid in a hexagonal cavity considering the impacts of a sloping magnetic field in one-component nanofluid model. The inclined walls of the cavity are maintained at a constantly low temperature, while the bottom wall is uniformly heated. The upper wall, however, is regarded as adiabatic. The nanofluid thermal conductivity model incorporates the impact of Brownian motion. The Galerkin weighted residual finite element method has been employed to solve the governing dimensionless equations. The results are provided regarding the average Nu, streamlines, and isotherms. The study uses response surface methodology to analyze the sensitivity of parameters such as the Ha, Ra, and nanoparticle volume percentage. Using a response surface policy allows for optimizing the process and identifying the most favorable circumstances to achieve the maximum thermal transfer rate. The flow pattern of the nanofluid is significantly affected by the magnetic field and its alignment. The numerical results indicate a significant rise in the average Nu as the nanoparticle volume percentage, magnetic field inclination angle, nanoparticle type factor, and Ra increase. Conversely, the Hartmann number and the nanoparticle's diameter have contrasting effects. When considering Brownian motion, the average Nu grows by 225.89 % for Ra = 106 with ϕ = 0.03 and 25.28 % for the other case. The optimal condition for heat transfer occurs when Ra = 106, Ha = 4, and ϕ =0.03 while keeping the other parameters constant.

Enhancing Natural Convection Heat Transfer Through Dome-Shaped Nanofluid Enclosures: Two-Phase Simulation Analysis

This study utilizes numerical analysis to investigate laminar flow and natural convective heat transfer of nanofluids (NFs) within dome-shaped enclosures (DSEs). The horizontal walls of the enclosure are adiabatic, while the vertical walls on the right and left are maintained at isothermal conditions with low and high temperatures, respectively. The study focuses on examining the impact of DSEs on flow patterns and natural convection (N.C.) under varying parameters, including Rayleigh numbers (Ra), Lewis numbers (Le), enclosure inclination angles, dome angles, and buoyancy ratio number (Nr). The Prandtl number (Pr) and nanoparticle volume fraction are consistently maintained at 10 and 0.05, respectively. The governing equations have been resolved by applying the Eulerian–Eulerian two-phase model. The study reveals that the DSE significantly influences flow dynamics, leading to smoother circulation patterns that intensify convection currents. This movement of hot fluid toward cooler regions within the enclosure enhances natural convective heat transfer. Across all enclosure inclination angles, the average Nusselt number (Nu) increases with higher Ra, while the Le remains constant at 4. Significantly, due to its robust convective currents, the average Nu in the DSE with a 45° dome angle surpasses those of corresponding square and rectangular enclosures.

The Bibliometric Review on Convective Heat Transfer of Nanofluid

The Bibliometric Review on Convective Heat Transfer of Nanofluid

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.

Computational Fluid Dynamics Heat Transfer Analysis of Double Pipe Heat Exchanger and Flow Characteristics Using Nanofluid TiO2 with Water

A device called a heat exchanger is used to exchange heat transfer between two fluids with different temperatures. Because of its durability and ability to handle high-pressure application, the concentric double pipe heat exchangers are widely utilized for numerous industrial applications. To conserve pumping power energy, many researchers were involved in study of the nanoparticles to be embedded in the fluid, which will enrich the fluid thermal conductivity and surface area. This article demonstrates the flow characteristics and convective heat transfer of nanofluids containing 0.2, 0.4 and 0.6 of vol% TiO2 nanoparticles dispersed in water under turbulent conditions, which mainly can be used for cooling nuclear reactors applications. Reynolds numbers varying from 4000 to 18,000 are examined numerically. The convective heat transfer coefficient results of the nanofluid agree well against experimental data, which are slightly more than that of base water at 1.94%. The results of the numerical model showed that the convective heat transfer coefficient of nanofluids will increase when the Reynolds and volume fraction increases. By increasing the temperature of the annular hot water, the heat transfer rate will increase, showing no major impact to the convective heat transfer coefficient of nanofluids. A generalised solution predicting the convective heat transfer coefficient for extensive nanoparticle materials is proposed. The conclusion of the empirical equation is tested among published data and the results are highly congruent, confirming the strength of the gamma equation.

Expression of Concern: Numerical study of entropy generation in the convection heat transfer of nanofluid inside a tilted closed compartment with five constant-temperature heat sources in the presence of a magnetic field

Expression of Concern: Numerical study of entropy generation in the convection heat transfer of nanofluid inside a tilted closed compartment with five constant-temperature heat sources in the presence of a magnetic field

Application of Caputo fractional approach to MHD Casson nanofluid with alumina nanoparticles of various shape factors on an inclined quadratic translated plate

The present study aims to examine the effect of convective heat transfer of nanofluid past an inclined plate. This paper scrutinizes heat transfer over an inclined surface of alumina nanofluids under the influence of radiation and magnetic fields with temperature-dependent thermophysical properties. The mathematical findings of velocity and temperature distributions are examined and visualized using non-dimensional flow parameters. The core of the research is to know the impact of using shape effects of alumina nanoparticles with a variety of base fluids like water, ethylene glycol, and engine oil. The outcomes concluded that the friction of the non-Newtonian viscous fluid decreased with increasing the inclination of the surface. The governing equations of the flow have been developed by using a few approximations such as Boussinesq's, and Roseland's. Using the dimensional analysis, the initial governing equations are simplified to dimensionless partial differential equations. A fractional model is developed using the Caputo fractional derivative. The solution of the proposed fractional partial differential equations is obtained in terms of special functions, Wright function, and Mittag-Leffler function by using the Laplace transformation method. Based on the interpretation, it is found that a reduction in velocity is observed with an increase in the angle of inclination i.e., γ = π/3 to γ = π/2. From the analysis, it is found that alumina/engine oil can carry higher temperatures than compared to other nanofluids and thus is a good option for heat transfer devices.

Natural convection heat transfer of a hybrid nanofluid in a permeable quadrantal enclosure with heat generation

This study investigates the steady laminar natural convection phenomenon within a quadrantal enclosure occupied by a fluid-saturated porous medium. The enclosure undergoes internal heat generation and magnetohydrodynamic buoyancy-driven thermal energy transfer. The governing equations were nondimensionalized and resolved utilizing the FEM. The research examined the impacts of heat generation and the porous medium presence on streamlines, isotherms, and heat transfer rate from the enclosure walls. The results were obtained for the following parameter ranges: 103≤Ra≤106, 0≤Ha≤100, 0≤ϕ≤0.05. The results demonstrate the average Nusselt number depends on ϕ, exhibiting an increase with rising ϕ. Investigations revealed the Nusselt number on the heated bottom wall substantially increases with both the Rayleigh number (Ra = 105 and 106) and volume fraction ϕ = 0.01 and 0.05, with augmentations up to 9.4536 and 10.852. Additionally, complex interplay was found between the heat generation parameter λ = -5, when ϕ = 0.01, Ra = 106Nu¯ rose to 11.026 and when λ=5, yet for ϕ = 0.05, Nu¯ steeply decreased to 4.0464. The outcomes of this research could potentially improve the efficiency of heat exchangers, solar collectors, and other analogous devices reliant on natural convection heat transfer.

Investigation of forced convection of a novel hybrid nanofluid containing NEPCM in a square microchannel: Application of single-phase and Eulerian-Eulerian two-phase models

In the present study, laminar forced convection flow and heat transfer of novel hybrid nanofluid of Al 2 O 3 -n-octadecane/water through a horizontal microchannel under a constant wall heat flux condition are investigated. N-octadecane is regarded as a nano-encapsulated phase change material (NEPCM). Simulations are performed utilizing single-phase and Eulerian-Eulerian two-phase models. Governing equations are discretized by finite volume method and then solved using SIMPLE algorithm. Effects of nanoparticles volume fraction ( φ ), Reynolds number ( Re ), and melting range ( T mr ) on thermal and hydrodynamic parameters of hybrid nanofluid are evaluated. It is shown that predictions by Eulerian-Eulerian approach are more accurate than those by single-phase approach when compared to available experimental data. Addition of Al 2 O 3 and n-octadecane nanoparticles to water-based fluid leads to a reduction in fluid and wall temperatures, which is intensified at higher φ and Re . Also, these nanoparticles do not have a significant effect on hydrodynamic development of flow, while they delay its thermal development. NEPCM with a higher T mr only slightly improves thermal performance of hybrid nanofluid, which is more noticeable in single-phase procedure. Total efficiency of hybrid nanofluid ( η hnf ) is amplified by raising φ for both approaches. This augmentation is more evident in Eulerian-Eulerian model due to better thermal and hydrodynamic performances. Maximum increases in η hnf concerning single-phase and Eulerian-Eulerian models are 27% and 60%, respectively, occurring at φ Al 2 O 3 = 1 % and φ n ‐ octadecane = 10 % . Therefore, this type of hybrid nanofluids, because of its enhanced thermo-physical properties, can be considered as a suitable candidate for thermal energy storage, heat transfer, and renewable energy applications.

Optimization and Sensitivity Analysis of Natural Convective Heat Transfer of Nanofluids inside a Quarter-Circular Enclosure Using Response Surface Methodology

Optimization and Sensitivity Analysis of Natural Convective Heat Transfer of Nanofluids inside a Quarter-Circular Enclosure Using Response Surface Methodology

Effect of the Presence of Porous Medium on the Particles Distribution in Nanofluid Convective Heat Transfer, Case Study: Elbow Micro-Channel

Effect of the Presence of Porous Medium on the Particles Distribution in Nanofluid Convective Heat Transfer, Case Study: Elbow Micro-Channel

Impact of Convection and Rotation on Advanced Thermal Energy Storage Using Nanoencapsulated Phase Change Materials in Wavy Enclosures

Free convection heat transfer in hybrid nanofluids in a differentially heated wavy enclosure is studied. The wavy enclosure moves at a constant counterclockwise rotational speed along its longitudinal axis. The enclosure is filled with a hybrid nanofluids consisting of water (H2O) and nanoencapsulated phase change materials (NEPCMs). These NEPCMs consist of a polyurethane coating and a core of N‐nonadecane, which undergoes a phase transition and has the capacity to retain or emit a significant quantity of latent heat. The dimensionless forms of the governing equations have been solved using finite element method. The validity of the present code is demonstrated by comparing its predictions with published results. The governing parameters under consideration are the corrugated number, 0 ≤ N ≤ 3, the volume fraction of hybrid nanoparticles, 0.0 ≤ ϕ ≤ 0.05, the Taylor number, 8 × 102 ≤ TaH2O ≤ 2 × 104. Changing the rotation speed is found to alter the melting and solidification zones in terms of pathways and size zones. The melting zone has a large size at moderate wave number, and its size shrinks and shifts downward as the wave number increases. An increase in the heat transfer rate values up to 38% is obtained when the concentration is adjusted from 1% to 5% for N = 1.

The Thematic Review on Convective Heat Transfer of Nanofluid over Horizontal Circular Cylinder

Convective heat transfer refers to thermal energy transfer from one place to another due to the movement of fluid. To increase the performance of thermal energy transfer, nanoparticles are diluted into the fluid resulting nanofluid. Even though there are lots of studies have been conducted on the convection heat transfer of nanofluid, there are scarce studies that review the patterns of mainly used mathematical model, boundary conditions, surface geometry and method of solution. Therefore, this paper aims to review the studies on convective heat transfer of nanofluid over horizontal circular cylinder. The focus is to review published articles in the year 2014 until 2023. The reviewed articles were extracted using the advanced documents search function in SCOPUS and WOS databases. Of 67 identified articles, only 37 were selected after undergoing screening process. The result of this thematic review identifies that besides Buongiorno and Tiwari and Das models, mathematical models for non-Newtonian fluid like Viscoelastic, Casson, Jeffrey and Williamson models are also used in modeling convection heat transfer of nanofluid.

Molecular study on convective heat transfer of nanofluid in nanochannel: effect of CNT particles

Molecular study on convective heat transfer of nanofluid in nanochannel: effect of CNT particles

Practical Challenges in Nanofluid Convective Heat Transfer Inside Silicon Microchannels

Despite numerous studies on nanofluids in microchannel heat sinks (MCHSs), they are not yet commercialized due to long-term stability issues and high maintenance costs. Therefore, this study explores the impact of nanofluids and nanoparticle clustering on single-phase convective heat transfer inside microchannels under laminar conditions. Water and commercially available water-based nanosuspensions, including Al2O3-water (30–60 nm), TiO2-water (5–30 nm), and polystyrene-water (50 nm), are circulated through silicon MCHS having rectangular channels integrated into a closed flow loop. To assess the in situ and real-time nanoparticle clustering during heat transfer experiments, Light Extinction Spectroscopy (LES) is applied as a non-intrusive measurement technique on nanofluids without any fluid sampling. Our findings reveal the appearance of nanofluid discoloration with no measurable increase in heat transfer coefficient. This unexpected change is attributed to the interplay of abrasion, erosion, and corrosion phenomena, likely triggered by the clustering of nanoparticles within the silicon microchannels—a novel insight into the complex dynamics of nanofluid behavior (an increase in the De Brouckere mean diameter from 11 nm to 107.3 nm over a 2.5 h period for TiO2 nanoparticles). The resulting material loss could not be mitigated by altering the nanoparticle material, which may impede heat transfer enhancement under tested conditions.

Studying Alumina–Water Nanofluid Two-Phase Heat Transfer in a Novel E-Shaped Porous Cavity via Introducing New Thermal Conductivity Correlation

Investigating natural convection heat transfer of nanofluids in various geometries has garnered significant attention due to its potential applications across several disciplines. This study presents a numerical simulation of the natural convection heat transfer and entropy generation process in an E-shaped porous cavity filled with nanofluids, implementing Buongiorno’s simulation model. Analyzing the behavior of individual nanoparticles, or even the entire nanofluid system at the molecular level, can be extremely computationally intensive. Symmetry is a fundamental concept in science that can help reduce this computational burden considerably. In this study, nanofluids are frequently conceived of as a combination of water and Al2O3 nanoparticles at a concentration of up to 4% by volume. A unique correlation was proposed to model the effective thermal conductivity of nanofluids. The average Nusselt number, entropy production, and Rayleigh number have been illustrated to exhibit a decreasing trend when the volume concentration of nanoparticles inside the porous cavity rises; the 4% vol. water–alumina NFs yield 17.35% less average Nu number compared to the base water.

Effect of Nanoparticle Material, Porosity and Thermal Radiation on Forced Convection Heat Transfer of Cu-Water and CuO-Water Nanofluids over a Stretching Sheet

Effect of Nanoparticle Material, Porosity and Thermal Radiation on Forced Convection Heat Transfer of Cu-Water and CuO-Water Nanofluids over a Stretching Sheet

Irreversibility analysis of Magnetohydrodynamic (MHD) mixed convection flow of viscoelastic hybrid nanofluid flow in a channel

This manuscript delves into the analysis of irreversibility in Magnetohydrodynamic (MHD) mixed convection flow of a viscoelastic hybrid nanofluid within a vertical channel. The study adopts a parallel plate configuration and employs Aluminum oxide (Al2O3) and Titanium oxide (TiO2) nanoparticles dispersed in a Carboxymethyl cellulose (CMC)-water base fluid. Utilizing similarity transformations, the governing partial differential equations (PDEs) are converted into a set of ordinary differential equations (ODEs), streamlining the mathematical model. These ODEs are then solved using the homotopy analysis method via Mathematica software for various governing parameter values. Key parameters including the Brinkman number, volume fractions of nanoparticles, magnetic effects, and wall temperature parameter are systematically investigated. Noteworthy insights include that volume fraction and magnetic parameter augments velocity at the left wall and slows down it toward the right wall; Brinkman number and wall temperature parameters significant in elevating temperature; Entropy and Bejan number respond differently to variations in the Brinkman number. Entropy escalates with increasing magnetic parameter, while the Bejan number declines. Illustrated through graphs, these findings enrich the comprehension of MHD mixed convection flow and heat transfer in viscoelastic hybrid nanofluids, elucidating irreversibility aspects tied to such systems.

An experimental study of the influence of Fe3O4, MWCNT-Fe3O4, and Fe3O4@MWCNT nanoparticles on the thermophysical characteristics and laminar convective heat transfer of nanofluids: A comparative study

In this study, the main objective is to investigate the impact of single, hybrid, and doped magnetic nanoparticles (NPs) on the convective heat transfer capabilities of a water/ethylene glycol (EG)-based nanofluid (NF) under the influence of a magnetic field (MF). The NFs were prepared by incorporating Fe3O4, Fe3O4-multi-walled carbon nanotubes (Fe3O4-MWCNT), and Fe3O4@MWCNT in concentrations of 0.05, 0.1, and 0.2 wt.%. The NPs were characterized using various techniques such as XRD, SEM, VSM, Raman spectroscopy, and FTIR to confirm their properties. The stability of the NFs was assessed through dynamic DLS and zeta potential measurements. The study then focused on evaluating the effects of these nano-additives on thermal conductivity (TC), viscosity at 25 °C, convective heat transfer coefficient (CHTC), and friction factor in a circular tube under laminar flow regime with a constant wall flux, both with and without the application of a MF. The results of present preliminary study with limited samples revealed that the CHTC of NFs containing Fe3O4 and Fe3O4@MWCNT NPs increased with NP concentration and application of a MF, with maximum increases of approximately 19.01 % and 32.84 %, respectively. However, in the case of NFs containing MWCNT-Fe3O4 NPs, the CHTC decreased when the MF was applied at concentrations higher than 0.1 wt.%. Furthermore, the NFs containing 0.2 wt.% of Fe3O4, MWCNT-Fe3O4, and Fe3O4@MWCNT NPs exhibited the highest friction when subjected to a 400 G MF, resulting in increases of 5.2 %, 9.2 %, and 5.9 %, respectively, compared to the base fluid. The performance index, which assesses the effectiveness of using NFs instead of the base fluid, indicated that all samples had a performance index greater than one, indicating their efficacy. The maximum performance index achieved was 1.343, corresponding to the NF containing 0.2 wt.% of Fe3O4@MWCNT NPs at a Reynolds number (Re) of 2200 and a MF strength of 400 G.