Variations in drag and heat transfer at a vertical plate due to steady flow of a colloidal suspension of nano particles in a base fluid

The aim of this study is to investigate how heat and mass transfer impacts the unsteady incompressible flow of Maxwell fluid. An infinite vertical plate with ramped and isothermal wall temperature and concentration boundary conditions is considered with the Maxwell fluid. Furthermore, in this study, engine oil has been taken as a base fluid due to its enormous applications in modern science and technologies. To see the importance of nanofluids, we have suspended molybdenum disulfide in engine oil base fluid to enhance its heat transfer rate. To investigate the flow regime, the system of equations was derived in the form of partial differential equations. The exact solutions to the complex system are obtained using the Laplace transform technique. Graphically, the impact of different embedded parameters on velocity, temperature, and concentration distributions has been shown. Through using the graphical analysis, we were interested in comparing the velocity, temperature, and concentration profiles for ramped and isothermal wall temperature and concentration. The magnitude of velocity, temperature, and concentration distributions is greater for an isothermal wall and less for a ramped wall, according to our observations. We observed that adding molybdenum disulfide nanoparticles to the engine oil increased the heat transfer up to 12.899%. Finally, the corresponding skin friction, Nusselt number, and Sherwood number have been calculated and presented in a tabular form.

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Preparation of binary nanofluid with heat transfer additives by particle surface functionalisation

Emergent Materials ◽

10.1007/s42247-021-00260-z ◽

2021 ◽

Author(s):

Umar Aliyu Muhammad ◽

Debabratta Bhattacharyya ◽

Jose Louis Endrino ◽

Sonia Fereres

Keyword(s):

Heat Transfer ◽

Base Fluid ◽

Concentration Distribution ◽

Colloidal Suspension ◽

Particle Surface ◽

Lithium Bromide ◽

Synthesis Methods ◽

Distribution Analysis ◽

Surface Functionalisation ◽

Fluid Interaction

AbstractCurrent binary nanofluid synthesis methods with heat transfer additives lack an understanding of the chemistry of the nanoparticle-additive-base fluid interaction, which plays a significant role in the adsorption of the surfactant on the nanoparticle surface. Consequently, this leads to the formation of aggregates within the nanofluid after a couple of days, affecting the stability of the colloidal suspension. Here, a lithium bromide-alumina salt-based nanofluid is proposed following a newly developed synthesis method including particle surface functionalisation. The new procedure developed allows the initial preparation of the nanoparticles with the surfactant as the first step (surface functionalisation) and then the preparation of the base fluid with a dispersion stabilising agent (Gum Arabic) separately. This is then followed by the dispersion of the prepared alumina nanoparticles into the base fluid, by stirring and ultrasonication to produce the final nanofluid, lithium bromide-water (LiBr-H2O)-alumina nanofluid. Until now, proper procedures have not been reported for the nanofluid synthesis combining surfactant and dispersant and the chemistry of nanoparticles-surfactant-base fluid interaction, which was thoroughly investigated in the new approach. The fluid prepared by both the conventional and new procedures was characterised and analysed simultaneously. A thermal conductivity enhancement of 3% was achieved by using the surface functionalisation method, with greater particle concentration distribution (number of particles in suspension) of 22.7% over the conventional procedure. It also achieved a 5% decrease in dynamic viscosity. On the other hand, a Mouromtseff number value between 0.7 and 1.8 was obtained for the fluid at 293 K and 373 K temperature range, indicating a strong heat transfer capability. It was apparent from the particle size and concentration distribution analysis conducted that this procedure produced a more stable nanofluid with a high distribution of nanoparticles within the fluid. This allows high improvement of thermal properties of the fluid. Graphical abstract Graphical abstract of a new procedure for nanofluid synthesis with heat transfer additives using the two-step method

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Performance Improvement of Base Fluid Heat Transfer Medium Using Nano Fluid Particles

Journal of New Materials for Electrochemical Systems ◽

10.14447/jnmes.v23i4.a03 ◽

2020 ◽

Vol 23 (4) ◽

pp. 235-243

Author(s):

T. Sathish

Keyword(s):

Heat Transfer ◽

Performance Improvement ◽

Base Fluid ◽

Flow Problem ◽

Thermal Characteristics ◽

Nano Particles ◽

Simulation Tool ◽

Heat Transfer Medium ◽

Nano Fluid ◽

Nano Fluids

Base fluids like water, ethylene glycolandengineoilare conventionally used as a heat transfer medium. The performance of heat transferred is improved in the conventional fluids with the addition of Nano particles. Hence, this paper considers the forced conventional flow problem over the base fluid within a uniform heated tube placed on a wall. The analysis of heattransferco-efficientis done through a constant Reynoldsnumberfor both Nano and base fluid with a simulation tool. Further, a comparative analysis is carried out with heat transfer coefficient over the base and various Nano fluids. It is seen that the Nano fluids has a better performance due to its better thermal characteristics under standard conditions.

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Heat Transfer Enhancement by the Usage of Low Concentration MgO-Water Nanofluid

International Journal of Engineering and Advanced Technology - Regular Issue ◽

10.35940/ijeat.a9528.109119 ◽

2019 ◽

Vol 9 (1) ◽

pp. 1985-1990

Keyword(s):

Heat Transfer ◽

Heat Transfer Enhancement ◽

Base Fluid ◽

Particle Concentration ◽

Volume Concentration ◽

Nano Particles ◽

Distilled Water ◽

Nano Particle ◽

Transfer Enhancement ◽

Fluid Properties

The current tentative work proposes the convective heat transfer enhancement by means of using low concentrations MgO-Water nanofluid flowing via tube. Nanofluid is the rising heat transfer fluids which consists solid nano-sized particles suspended in base fluid. Total three volume concentrations (0.005%, 0.01%, and 0.05%) and four unique sizes of nano particle (7 nm, 40nm, 60 nm, 100nm) are used to prepare nanofluid with distilled water. There are different correlations available to find nano fluid properties but they are not applicable as these are dependent on number of parameter like base fluid properties, particle size, shape and concentration of nano particle in a base fluid. Therefore actual measurements of different properties are carried out. Experimental investigation is executed for different Reynolds no, particle concentration and different size of nano particle. It is experimental that average heat transfer augmentation of 44.73% is obtained for 0.05% volume concentration (40 nm size) as compared to distilled water. It is found that there is augmentation of heat transfer with amplifying in particle concentration and reducing in size of nano particles. The typical improvement in Nusselt number for particle sizes of 7 nm, 40 nm, 60 and 100nm are found to be 37.76%, 36.53%, 35.15% and 32.26% respectively as compared to distilled water. It is found that as volume concentration increases and size of nanoparticle decreases there is augmentation of heat transfer.

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Axisymmetric Hybrid Nanofluid Flow Due to a Convectively Heated Stretching/Shrinking Disk

Journal of Advanced Research in Fluid Mechanics and Thermal Sciences ◽

10.37934/arfmts.85.1.113124 ◽

2021 ◽

Vol 85 (1) ◽

pp. 113-124

Author(s):

Najiyah Safwa Khashi'ie ◽

Iskandar Waini ◽

Ioan Pop ◽

Nurul Amira Zainal ◽

Abdul Rahman Mohd Kasim

Keyword(s):

Heat Transfer ◽

Laminar Flow ◽

Metal Oxide ◽

Steady Flow ◽

Base Fluid ◽

Similarity Transformation ◽

Hybrid Nanofluid ◽

Al2o3 Nanoparticles ◽

Nanofluid Flow ◽

Transfer Operation

This significant study is designed to analyze the axisymmetric hybrid nanofluid flow with heat transfer on a convectively heated stretching/shrinking disk. The combination of metal (Cu) and metal oxide (Al2O3) nanoparticles with water (H2O) as the base fluid is used for the analysis. Similarity transformation is adopted to reduce the complexity of the PDEs into a system of ODEs. The utilization of suction in maintaining the steady flow solution for the shrinking disk case discloses the presence of dual solutions. Besides, an upsurge of Biot number and suction’s strength enhances the heat transfer operation. The application of Cu-Al2O3/water nanofluid can extend the range of solutions’ existence and consequently, decelerate the separation of laminar flow.

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Preparation and Characterisation of Graphene Nanofluid: To Be Used As Coolant

Volume 2A: Advanced Manufacturing ◽

10.1115/imece2020-23102 ◽

2020 ◽

Author(s):

Senthil Kumar Velukkudi Santhanam ◽

Dolly Austen Thomas ◽

Mystica Augustine Michael Duke ◽

Viswanathan Doraiswamy

Keyword(s):

Heat Transfer ◽

Thermal Conductivity ◽

Base Fluid ◽

Solid Phase ◽

Nano Particles ◽

Planar Geometry ◽

Phase System ◽

Transfer Coefficients ◽

Two Phase ◽

The Stability

Abstract In the recent years, nanofluids embarked as a new class of fluids with improved thermophysical properties such as thermal conductivity, thermal diffusivity, viscosity, and convective heat transfer coefficients thus promoting better heat transfer. Nanofluids consists of two-phase system where the nano sized solid phase (nanoparticles) is dispersed into a base fluid. Graphene is a material which has two-dimensional planar geometry with thermal conductivity of the order of 5000 W/mK. Nanoparticles in the form of thin flakes as small as 50 nm, 100 nm has been used in this study. Two step technique is the used method for preparing nanofluids. Inclusion of additives in small quantity, enhance the durability of the nano particles inside the conventional base fluids. The stability of the solid nano particles inside the conventional base fluid is increased by using surfactants. The heat transfer capacity and stability of the fluids are considered as the basic properties for investigation. The nanofluids characterization studies were drawn from the SEM, XRD and thermal conductivity results. Hot wire method was used to determine the thermal conductivity of the nanofluids. The preparation and properties of graphene based nanofluids which can be used as coolant are studied in this work.

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Study of Convective Heat Transfer for Turbulent Flow of Nanofluids Through Corrugated Channels

Volume 8A: Heat Transfer and Thermal Engineering ◽

10.1115/imece2014-39061 ◽

2014 ◽

Cited By ~ 1

Author(s):

Shafi Noor ◽

M. Monjurul Ehsan ◽

Mohammed S. Mayeed ◽

A. K. M. Sadrul Islam

Keyword(s):

Heat Transfer ◽

Reynolds Number ◽

Heat Transfer Rate ◽

Transfer Rate ◽

Base Fluid ◽

Volume Fraction ◽

Nano Particles ◽

Turbulent Heat Transfer ◽

Corrugated Channel ◽

Wave Channel

Numerical study of turbulent heat transfer of nanofluid through a corrugated channel is presented. The finite volume method is used to solve the transport equation for the momentum, energy and turbulence quantities adopting a single phase approach. The corrugated channels are sine-shaped, V-shaped and rectangular shaped with amplitude (a/H) and wave length (λ/H) of 0.15 and 1 respectively. Three different nano-particles such as aluminum oxide (Al2O3), Copper (Cu) and titanium dioxide (TiO2) with different volume fraction (1%, 3% and 5%) using water as the base fluid are analyzed for a range of Reynolds number from 2000 to 14,000 with constant heat flux at the corrugated walls. Realizable k-ε turbulence model with enhanced wall treatment is considered. For all three geometries, average Nusselt number for the corrugated section is obtained. The result reveals that increasing the Reynolds number and volume fraction of nanoparticle in the base fluid has an effect of increasing the heat transfer rate. The sine shaped channel gives a better heat transfer enhancement compared to other two geometries up to Re = 8200 for 3% volume fraction of Al2O3-water nanofluid. At Reynolds number higher than this, rectangular shaped corrugated channel gives better heat transfer rate. Among the nano-particles, Al2O3 gives a higher heat transfer rate in all three corrugated channels. The enhancement of heat transfer is about 10.5% to 50.15% compared to water for the flow of Al2O3-water nanofluid through sine wave channel depending on the Reynolds number and volume fraction.

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