Convection Heat Transfer Of Nanofluid Research Articles

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.

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.

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

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.

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.

The Mixed of Hybrid Nanofluid GO-MoS2/Engine Oil Over a Shrinking Sheet with Mass Flux Effect: Reiner-Philippoff Model

The mixed convection flow and heat transfer of the hybrid nanofluid over a shrinking sheet are investigated. Molybdenum disulphide (MoS2) and graphene oxide (GO) are employed as two hybrid nanoparticles while engine oil (EO) as the base fluid is considered. In this study, the Reiner-Philippoff model as one of non-Newtonian types is deliberated since it has the ability to function on three distinct types of fluids: viscous, shear thickening and shear thinning. The Reiner-Philippoff relation, the momentum and energy equations under Tiwari and Das model are all employed in the study. Influences from mass flux are also considered in the flow. Before computation using the bvp4c function in MATLAB, the respected equations are first converted into ordinary differential equation form using the similarity transformation. When the established and current models are discovered to be identical in a specific case, a direct comparative investigation is conducted to confirm the correctness of the current model. In addition, the present results are shown graphically and in tabular form. It is hypothesized that the presence of a hybrid nanofluid significantly affects the fluid characteristic and gives more satisfactory results than a single nanofluid. The skin friction coefficient and heat transfer rate of hybrid nanofluids are greater than the nanofluids. In terms of velocity and temperature profile, the reduction in velocity and the enhancement in temperature profile are caused by a rise in the Reiner-Philippoff parameter. The same outcome is also seen when the volume fraction of hybrid nanofluids increases.

Correction: Alshehri et al. Unsteady Convective MHD Flow and Heat Transfer of a Viscous Nanofluid across a Porous Stretching/Shrinking Surface: Existence of Multiple Solutions. Crystals 2021, 11, 1359

We ought to correct the misprinted terms in our published paper ‘Unsteady Convective MHD Flow and Heat Transfer of a Viscous Nanofluid across a Porous Stretching/Shrinking Surface: Existence of Multiple Solutions’ [Crystals2021, 11, 1359] [...]

Ferro-hydrodynamic induced convection flow and heat transfer of nanofluids in a corrugated wall enclosure

This study aims to improve heat transfer by utilizing Kelvin forces and inducing magnetic-induced convection in ferro-hydrodynamic convection, in conjunction with nanoparticle migrations. The fundamental equations governing the conservation of mass, momentum, energy, and nanoparticle mass were formulated as partial differential equations. As primary terms, the model incorporated the buoyancy, Lorenz, and Kelvin forces. In this context, temperature variations in the presence of a variable magnetic field generate a temperature-dependent body force. This can induce fluid circulation. Thus, even without gravitational force, magnetic force can stimulate convection heat transfer flows. The study thoroughly examined the impact of magnetic source placement on heat transfer. An increase in Ha from 0 to 100 reduced the average Nusselt number (NuAvg) by approximately 60% in all cases, regardless of the magnetic source position. However, the magnetic field number (Mnf) and its effect on NuAvg are dependent on the magnetic source's position.

Experimental Investigations of Forced Convection of Nanofluids in Smooth, Horizontal, Round Tubes: A Review

A comprehensive review of published works dealing with experimental studies of forced convection heat transfer of nanofluids is presented. The survey is limited to straight, smooth, and round tubes. Moreover, only mono nanofluids exhibiting Newtonian behaviour are considered. Works on experimental research of forced convection in tubes are presented in a chronological order in the first part of the article. In this part, attention was paid to the influence of nanoparticles on the intensification of heat transfer. Information on the tested nanofluids, the measurement technique used, and the measurement range are presented in tabular form. Correlation equations proposed by individual researchers are also presented. In order to explain the controversy regarding the different influences of nanoparticles on the intensity of heat transfer during forced convection of nanofluids, the second part of the paper presents a comparison of the test results obtained by different researchers for the same nanofluid, possibly under the same thermal and flow conditions. Finally, the main conclusions are discussed.

Effects of magnetic field on natural convective heat transfer of nanofluid flow in a two-dimensional rectangular cavity in the presence of constant-temperature triangular blades on the bottom wall

The simulation of the natural convective heat transfer (HTR) of nanofluid (NFD) flow in a two-dimensional rectangular cavity is performed in this paper. A magnetic field (MFD) is placed close to the cavity and the NFD. The top wall of the cavity is cold, and the side walls are insulated. Three isothermal triangular blades are mounted on the bottom wall at the same temperature as the wall. By changing the height of one of these blades from 0.1 to 0.7 and changing the location of this blade, three HTR models are estimated. Lattice Boltzmann method (LBM) and an in-house code are used for the simulations. The findings show that including the MFD lowers the Nu. The Nu is reduced with the Ha. Enhancing the length of the blades intensifies the average Nu for three studied models so that an increment in the blade length from 0.1 to 0.7 enhances the Nu from 9.3% to 18.5%, respectively. For the blade length of 0.1 and 0.3, model 2 has the maximum Nu, while model 1 has the maximum Nu for the blade length of 0.5 and 0.7.

MHD Marangoni convection heat transfer of Ag-Cu hybrid nanofluid under a stretching/shrinking sheet with the effect of suction

This paper examines the heat transfer characteristics of magnetohydrodynamics (MHD), suction, and Marangoni convection under the stretching/shrinking Ag–Cu hybrid nanofluid surface flow. First, the governing partial differential equations (PDEs) were transformed into ordinary differential equations (ODEs), and the numerical result was obtained using the boundary value problem solver (bvp4c) in MATLAB. The development of the Nusselt number, the velocity profile and the temperature profile was plotted, discussed and inspected. Next, this paper undergoes stability analysis and heat transfer rate comparison between water, nanofluid and hybrid nanofluid. The dual solutions were observed, and the upper branch solution is determined to be stable. Compared to water, the heat transfer rates of Ag–Cu hybrid nanofluid and Cu nanofluid were accelerated by 2.84% and 2.75%, respectively.

A Comprehensive Review of Nanofluid Heat Transfer in Porous Media

In the present paper, recent advances in the application of nanofluids in heat transfer in porous materials are reviewed. Efforts have been made to take a positive step in this field by scrutinizing the top papers published between 2018 and 2020. For that purpose, the various analytical methods used to describe the flow and heat transfer in different types of porous media are first thoroughly reviewed. In addition, the various models used to model nanofluids are described in detail. After reviewing these analysis methods, papers concerned with the natural convection heat transfer of nanofluids in porous media are evaluated first, followed by papers on the subject of forced convection heat transfer. Finally, we discuss articles related to mixed convection. Statistical results from the reviewed research regarding the representation of various parameters, such as the nanofluid type and the flow domain geometry, are analyzed, and directions for future research are finally suggested. The results reveal some precious facts. For instance, a change in the height of the solid and porous medium results in a change in the flow regime within the chamber; as a dimensionless permeability, the effect of Darcy's number on heat transfer is direct; and the effect of the porosity coefficient has a direct relationship with heat transfer: when the porosity coefficient is increased or decreased, the heat transfer will also increase or decrease. Additionally, a comprehensive review of nanofluid heat transfer in porous media and the relevant statical analysis are presented for the first time. The results show that Al2O3 nanoparticles in a base fluid of water with a proportion of 33.9% have the highest representation in the papers. Regarding the geometries studied, a square geometry accounted for 54% of the studies.

Numerical study of thermal performance of yield stress rheological liquid under suspension of hybrid nanostructures: The finite element approach

Enhancement of heat transfer employing nanofluids, studied numerically, observed profound effects in thermophysical and theological properties used in various applications such as avionics, laser diode, rocket nozzels and microelectronics. In this paper, the influence of thermal radiations and hybrid nanoparticles on free convection flow and heat transfer of Casson hybrid nanofluid over vertical plate is investigated. A mixture of pure water and ethylene glycol has been considered as a base Casson fluid while Copper oxide ([Formula: see text]) as nanofluid (single kind) and, Copper oxide ([Formula: see text]) and Silicon dioxide ([Formula: see text]) (double kind known as hybrid nanofluid) are disseminated in base Casson fluid mixture to be formed as hybrid nanofluid. The governing system of partial differential equations of the flow and heat transfer processes is converted to a system of well-posed coupled nonlinear ordinary differential equations by using the similarity transformations. The resulting system is solved using the Galerkin finite element (GFE) technique. The quadratic Lagrange polynomials are used as basis functions over the mesh of about 1000 to 2000 finite elements and the nonlinear system of order 6003 and upto 12003 is solved. The accuracy of developed numerical methods is confirmed by comparing their results with convection flow and heat transfer with nanoparticles. Thereafter, the said solutions are used to investigate the effects of thermal radiation, hybrid nanoparticle volume friction, Prandtl number, type of flow and heat transfer behavior. The innovative results of the present study reported higher velocities in suspensions with low sphericity particles and the radiation parameter is directly proportional to the temperature with the use of nano and hybrid nanoparticles. It has also been noted that the GFE method is a more stable numerical technique as compared with other existing analytic and semi-analytical methods.