Alumina Nanofluids Research Articles

An exergy and entropy generation investigation in microchannel heat sink utilizing alumina nanofluid at varied concentrations with conjugate heat transfer

An exergy and entropy generation investigation in microchannel heat sink utilizing alumina nanofluid at varied concentrations with conjugate heat transfer

Enhancing Photovoltaic Panel Performance through Hybrid Nanoparticle Cooling: A Study on Zinc Oxide and Aluminum Oxide Nanofluids

Enhancing Photovoltaic Panel Performance through Hybrid Nanoparticle Cooling: A Study on Zinc Oxide and Aluminum Oxide Nanofluids

Optimizing Oil Recovery with Eco-Friendly Biopolymer-Stabilized Aluminum Oxide Nanofluids: A Comparative Investigation of Egg and Soy Proteins

Optimizing Oil Recovery with Eco-Friendly Biopolymer-Stabilized Aluminum Oxide Nanofluids: A Comparative Investigation of Egg and Soy Proteins

Numerical Analysis and Design for Thermal Efficiency Optimization using Al2O3 Nanofluids in Shell and Tube Heat Exchangers

In this study, the efficacy of aluminum oxide (Al2O3) nanofluids at a 2% concentration for enhancing heat transfer in shell and tube heat exchangers is evaluated. By employing SOLIDWORKS for the innovative design and Computational Fluid Dynamics (CFD) for simulation, an improvement in heat transfer efficiency over traditional hot water systems is identified. Emphasizing the unique properties of Al2O3 nanofluids in augmenting heat transfer rates, the role of advanced CAD and simulation tools in engineering practices is highlighted. Results confirm nanofluids' benefits in improving thermal management systems, indicating their potential to decrease energy consumption and operational costs. Furthermore, the exploration of a novel design for heat exchangers, inspired by but distinct from existing market standards, suggests new avenues for the application of nanofluids in various industrial settings, marking a step towards more energy-efficient technologies.

Investigating the effect of using aluminum oxide nanofluid and twisted tapes with different twisted pitches on the heat transfer efficiency and using perceptron artificial neural networks in data prediction

This study investigates the effect of aluminum oxide nanofluid with 1% and 2% volume fractions (VFs) in four different tubes with identical bending and the uniform, low-high-low, low-high, and high-low-high longitudinal states with twist ratios of 0, 2 and 4. These tubes are affected by a constant thermal flux of 10000 W/m2 and Reynolds numbers of 2000-10000. For the numerical solution of these equations, the finite difference method on the basis of the control volume and the SIMPLEC algorithm and the K-ε-RNG method were applied for the turbulent flow modeling. The determined Nusselt number from the numerical methods were evaluated applying the perceptron neural network. The most optimal increase in the Nusselt number was in the twisted tube with twist ratio of 4 in the Reynolds number of 10,000 and VF of 1% and 2% nanofluid with increasing trend of length from low to high. The most optimal increase in Nusselt number compared to base fluid was about 25%. The sum of squared error and the relative error data obtained from the hyperbolic tangent function for the training and test data were 0.080-1.331 and 0.113-0.675, and from the sigmoid function for the training and test data were 0.093-0.392 and 0.097-0.147.

Cutting-Edge Machine Learning Techniques for Accurate Prediction of Agglomeration Size in Water–Alumina Nanofluids

Cutting-Edge Machine Learning Techniques for Accurate Prediction of Agglomeration Size in Water–Alumina Nanofluids

Experimental Characterization of Hydronic Air Coil Performance with Aluminum Oxide Nanofluids of Three Concentrations

This paper presents the continuation of experimental investigations conducted by the present authors to measure and compare the thermal and fluid dynamic performance of a residential hydronic air coil using nanofluids. The prior experiments were limited to testing only one volumetric concentration (1%) of aluminum oxide (Al2O3) nanofluid. They compared it with the base fluid, a 60% ethylene glycol/40% water mixture by mass (60% EG). The original tests revealed some deficiencies in the experimental setup, which was subsequently revised and improved. This paper summarizes the results of experiments from the improved test bed using three concentrations of Al2O3 nanofluids: 1, 2, and 3% volumetric concentrations prepared with an average particle size of 45 nm in a 60% EG dispersion. The test bed in these experiments simulates a small air handling system typical of heating, ventilation, and air conditioning (HVAC) applications in cold regions. Entering conditions for the air and liquid were selected to emulate typical commercial air handling systems operating in cold climates. Contrary to previous findings, our test results revealed that nanofluids did not perform as well as expected. Prior predictions from many analytical and numerical studies had promised significant performance gain. The performance of the 1% nanofluid was generally equal to that of the base fluid under identical inlet conditions. However, the performance of the 2% and 3% nanofluids was considerably lower than that of the base fluid. The higher concentration nanofluids exhibited heat rates up to 14.6% lower than the 60% EG and up to 44.3% lower heat transfer coefficient. The 1% Al2O3/60% EG exhibited a 100% higher pressure drop across the coil than the base fluid, considering equal heat output. This performance degradation was attributed to the inability to maintain nanofluid dispersion stability, agglomeration, and subsequent decline in the thermophysical properties.

Enhancing photovoltaic panel efficiency through passive cooling with nano-coated aluminum fins: a comparative study of zinc oxide and aluminum oxide nanofluids

Enhancing photovoltaic panel efficiency through passive cooling with nano-coated aluminum fins: a comparative study of zinc oxide and aluminum oxide nanofluids

Heat radiation absorption and irreversibility of electromagnetic Williamson hybridized Al2O3–CoFe2O4/H2O nanofluid: A concentrated power generation

The quest for alternative and ecosystem-friendly energy sources to reduce reliance on fossil fuels and minimize cost has stimulated studies on various energy-generating techniques. Solar energy is one of the renewable and low-cost power generation sources for domestic and industrial usage. To optimize the performance of solar power, nanofluids can be considered as the based material. This study focuses on the concentrated power generation through hybridization of electromagnetic Williamson aluminium oxide (Al2O3) and cobalt ferrite (CoFe2O4) nanofluids in water (H2O) with nonlinear radiation. Without the deformation of the material, the fluid is driven by nonlinear thermal convection and pressure gradient in a bounded device. The developed, transformed boundary value mathematical model is solved by the Chebyshev scheme coupled with the collocation integrating method. A theoretical analysis is carried out for the dependent-parameter sensitivities on the flow rate, heat distribution and entropy generation to enhance and maintain continuous power generation. The investigation revealed that the hybridized nanofluid enhanced the concentrated thermal power for about 12.23 %, and the fluid velocity field is raised by 3.45 % with increasing dependent parameters. The Williamson material term optimized the thermodynamic equilibrium of entropy generation.

Impact of Different Protrusions in Energy Transfer and Fluid Flow Characteristics Using Al₂O₃ Nanofluid in Pipe Flow

The study investigates how the protruded surface (the part sticking out of an otherwise flat surface) over the small channel affects flow characteristics and heat transfer within a circular flow regime, utilizing computational methods. This investigation uses an alumina nanofluid to compare and analyze the thermo-physical parameters of protruding pipes such as boxes, cylinders, dimples, and pyramids in pipe flow. Alumina nanofluid with varying volume fractions was evaluated as a thermo-fluid under laminar flow conditions, exploring its ability to enhance energy transmission (heat) over the protruded channels. The protruded surface induces turbulence around the protruded region, altering the coolant's physical characteristics. Since heat transfer predominantly occurs on surfaces, the alteration in surface geometry due to the protruded shape increases detectable heat transfer and the Nusselt number. With an increase in the volume percentage of nanofluids, there's a tendency for pressure loss to rise along the flow direction's centerline. The dimpled channel exhibits the highest Nusselt number among all protruding channels, indicating that increasing the Reynolds number also increases the surface heat transfer coefficient for all protrusions. When compared to the base fluid, cylindrical protrusions show the greatest pressure drop. Additionally, comparing a protruded channel with base fluid to one with a 4% volume of alumina nanofluid, it can be observed that the latter significantly improves heat transfer, followed by volume fractions of 1% to 3%.

The reversal of carbonate wettability via alumina nanofluids: Implications for hydrogen geological storage

Underground hydrogen storage (UHS) has been recognized as a key enabler of the industrial-scale implementation of a hydrogen-based economy. However, the efficiency and storage capacity of hydrogen (H2) in carbonate aquifers can be influenced by the presence of organic acids. Nevertheless, the existing literature contains few investigations of H2/calcite/brine wettability and the influence of organic acids on H2 storability in carbonate reservoirs. Therefore, the present study examines the influence of stearic acid on the dynamic H2/brine wettability of calcite substrates (as a proxy of carbonate formation) under various geological conditions (0.1–20 MPa at 323 K), equilibrated in 10 wt% NaCl brine. In addition, the application of various alumina nanofluid concentrations (0.05, 0.1, 0.25, and 0.75 wt%) is evaluated under the same experimental conditions for enhancing the organic-aged calcite wettability. The results demonstrate a significant impact of stearic acid on the dynamic (advancing and receding) contact angles of the calcite substrates, thereby resulting in a shift from intermediate water-wet to H2-wet conditions, representing an unfavorable state for H2 geological storage. Conversely, the application of alumina nanofluid on the organic-aged calcite substrate enhances the H2/brine/calcite wettability towards an intermediate water-wet state, which is more favorable for H2 residual trapping in carbonate formations. The optimal concentration of alumina nanofluid for the wettability modification of the organically aged calcite samples is found to be 0.25 wt%. These findings highlight the influence of organic acid contamination and the potential of alumina nanofluid application in enhancing H2 geo-storage conditions in carbonate reservoirs.

A hybrid MCDM optimization for utilization of novel set of biosynthesized nanofluids on thermal performance for solar thermal collectors

Recent advancements in solar technology have spurred researchers to develop a precise and cost-effective method for monitoring solar radiation across diverse environmental conditions. This study focuses on optimizing performance parameters by replacing conventional nanofluids, produced through chemical and physical processes, with biosynthesized counterparts. Biosynthesized nanoparticles, derived from biological sources like microorganisms or plants, offer a promising avenue for enhancing solar panel efficiency. Through the construction and testing of an integrated photovoltaic thermal system, varying operating parameters have been explored to maximize photovoltaic efficiency. The highest overall efficiency, reaching approximately 62 %, was achieved with biosynthesized Graphene oxide nanofluid under higher Direct Normal Irradiance (DNI) levels, while the lowest was observed with Aluminum oxide nanofluid at lower DNI values. Employing Multi-Criteria Decision methods such as Analytical Hierarchical Process (AHP) and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS), nanofluids were ranked based on criteria including Exergy loss, Surface temperature, Overall efficiency, and Electrical efficiency, with weights of 49.58 %, 28.43 %, 13.45 %, and 8.54 % respectively. TOPSIS prioritized Graphene Oxide as the most favorable nanofluid, followed by Copper-Oxide and Cerium-Oxide, while Aluminum-Oxide received the lowest priority in optimizing PV panel performance.

Microdroplet formation of water and alumina nanofluid in a T-junction microchannel

A scarcity of studies about nanofluids’ utilization in droplet formation inside microdevices currently hovers in the literature although potential applications of nanoparticles in a microfluidic environment are foreseen. For this purpose, experimentally assessing both nanofluid and microdroplet characteristics is fundamental. This work reports a series of experimental tests on the microdroplet formation of distilled water (DIW) and DIW-based aluminum oxide (Al2O3) nanofluid in a microfluidic T-junction. While water and nanofluid are used as the dispersed phase, mineral oil is used as the continuous phase. Microdroplet formation in the squeezing, transitional, and dripping regimes is characterized and scaling laws for the non-dimensional droplet volumes are presented. The effects of flow rate, capillary number, microchannel aspect ratio, and nanoparticle concentration are investigated. The addition of Al2O3 nanoparticles to the water is observed to have a major impact in the transitional regime (up to 40% increase), whereas in the dripping regime its influence is lower, with less than 10% difference. This was attributed to the nanofluid's enhanced interfacial tension and viscosity compared to the DIW, as well as possible adsorption at the surface.

Microfluidic flow synthesis of Al2O3 nanofluids for efficient phase-change boiling heat transfer enhancement of electronic devices

Integrating microchannel flow boiling heat transfer with nanofluids is an effective method for cooling electronic devices. However, traditional methods have significant limitations in achieving facile synthesis of nanofluids with desirable properties. In this study, we propose a straightforward synthesis strategy using microfluidic reactors, which enables continuous and high-throughout synthesis of Al2O3 nanofluids with high purity and long-term stability. These nanofluids were found to enhance boiling heat transfer performance by delaying bubbles coalescence, increasing surface nucleation sites, improving the nucleation rate, and enhancing wettability by observation of the bubble behavior. Specifically, the critical heat flux (CHF) and corresponding heat transfer coefficient (HTC) are increased by a maximum of 32 % and 26 %, respectively, with negligible change in pressure drop. Moreover, the heat transfer performance deteriorates with increasing concentration of alumina nanofluids. These findings not only provide guidance of microchannel flow boiling with nanofluids, but also present valuable insights for the application of nanofluids in two-phase cooling systems for electronic devices.

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.

Computational Approach on Convective-Magneto Trihybrid Nanoflow with Space Dependent Energy Source/Sink: Drug Delivery

Iron oxide, Silver, Aluminium oxide, these nanoparticles individually or combined help in drug delivery especially aluminium oxide nanofluid used in an anti-blood pressure drug called 'Telmisartan'. Alumina and silver particles are used in manufacturing nanocomposites which have more antimicrobial properties. This is the reason for the current study of ternary nanofluids natural convective flow and efficacy of energy transfer in a bi-directionally sheet. Currently, ternary nanofluids (Fe3O4, Ag, Al2O3) are being taken for analysis. Usual water (H2O) is the conventional base fluid. Two different combinations of ternary nanofluids are used to get the average heat transfer rate, mixture ratios (Fe3O4 + Ag) and (Fe3O4 + Ag + Al2O3) when subjected to a variety of physical influences, including thermal radiation, magnetic fields, heat production and absorption, and nanoparticle volume amount. It is possible to solve the developed set of equations numerical results using the Keller box (finite differences) method with the help of MATLAB programming. This method helps in solving higher order partial differential equation (PDEs) to ordinary differential equation (ODEs). The investigations findings demonstrated that the ternary hybrid nanofluids specific heat capacity is directly impacted by temperature. Numerical solutions for Nusselt number, velocity profile, skin friction coefficient, temperature profiles have represented with the help of graphs and tables. The ternary hybrid nanoflow (Fe3O4 + Ag + Al2O3/H2O) transmits more energy for increasing volume fractions, comparing to the hybrid nanofluid (Fe3O4 + Ag/H2O). The study reveals the fact that metal oxides transfer more heat from the system than that of metals. The estimated error of heat transfer rate is higher in alumina nanoflow followed by silver and iron oxide nanofluid flows. The streamlines are equally spaced, but the energy flow amount is higher for the case M, S = 1 than M, S = 2. But in the case of stretching ratio parameter, the amount energy flow in α = 0.5 > α = 1.0. An equal amount of energy flow is observed for varied Biot number.

Experimental study on heat-transfer characteristics of spray cooling for microchannel radiators

Spray cooling is an emerging and promising thermal-management solution with a wide range of applications. However, its application in engineering vehicles remains in the formative stage. In this study, an innovative spray-cooling system for engineering vehicles was proposed. The study, using thermocouples and visualisation methods, focused on how factors such as the spray angle, height, volume flow, nozzle aperture, and arrangement impact the uniformity of the surface temperature and heat-transfer enhancement. Optimal cooling was achieved using a spray angle of 60°, height of 90 mm, and flow rate of 500 l/h. Moreover, a nozzle aperture of 1.6 mm demonstrated superior efficiency in energy use and cooling. Higher temperature differentials (90–140 °C) enhanced the heat transfer but led to a 332.81 % increase in the non-uniformity of the surface temperature. Further, the study compared the spray-cooling efficiency between alumina nanofluids and deionised water. Alumina nanofluids with a 0.7 % mass fraction achieved a maximum heat-transfer coefficient of 450.6 W/(m2·K), 15.48 % higher than that of deionised water. Moreover, based on the experimental results, an empirical formula for enhanced heat transfer using spray cooling in construction machinery was developed, providing a valuable reference for guiding engineering practice. The proposed spray-cooling method, which exhibited a two- to three-time improvement over traditional air-cooled systems, holds considerable promise in the field of engineering vehicle applications.

Numerical Investigation on Thermal Performance of Nanofluid-Assisted Wickless Heat Pipes for Electronic Thermal Management

Abstract Heat pipes are passive heat transfer systems and serve as an effective thermal management solution for electronic devices. The adaptability of heat pipes makes these suited for a wide application range, especially in the field of electronic thermal management. The current study highlights the transient numerical analysis of wickless heat pipes (thermosyphons) for the thermal management of electronic devices. The thermal performance of the thermosyphon is analyzed using both copper oxide (CuO) and aluminum oxide (Al2O3) nanofluids with their concentrations at 1% and 5%. Deionized (DI) water is employed as a reference case for comparison. The study is carried out for variable heat inputs to the thermosyphon ranging 10–50 W for a time interval of 30 s. The idea is to analyze the effect of the evaporator heat input and the nanoparticles concentration on the temperature, heat transfer coefficient, thermal resistance, and effective thermal conductivity of the heat pipe. The results indicate that CuO nanoparticles at a 5% concentration lead to a maximum thermal resistance reduction of 4.31% at 50 W, while alumina nanoparticles at the same concentration lead to a more substantial reduction of 6.66% at the same heat load. The evaporator temperature varies between 377.52 K to 374.99 K using deionized water, and 376.95 K to 374.29 K using CuO nanofluid (at 1% concentration). The heat pipe's evaporator attains its highest convective heat transfer coefficient (437.91 W/m2K) by using alumina nanofluid with 1% nanoparticle concentration at 50 W. Moreover, the effective thermal conductivity of the heat pipe is enhanced by 5% and 7% for copper oxide and aluminum oxide nanofluids (with 5% concentration), respectively, at 50 W. Thus, the nanofluids play a significant role in improving the efficiency and reliability of electronic components. These findings demonstrate the potential of using the nanofluids in thermosyphons to enhance their thermal performance in electronic cooling applications.

Thermal and hydraulic performance of Al alloy-based 3D printed triangular microchannel heatsink governed by rough walls with graphene and alumina nanofluids as working liquid

Microchannel heat sinks (MCHS) are known for providing enhanced cooling performance but their fabrication requires complex and multi-step processes. The recent development of additive manufacturing has enabled the fabrication of state-of-art monolithic structures that had been impossible to build using conventional methods. In this work, a monolithic cross-flow triangular cross-section MCHS was fabricated from aluminum alloy (AlSi10Mg) using the Direct Metal Laser Sintering (DMLS) process. The microchannel wall surface roughness was measured and the cross-section shrinkage of the microchannels was compared with the initial design hydraulic diameter of 500 µm–1000 µm. The MCHS with an initial design hydraulic diameter of 750 µm possessed a relative wall surface roughness, R a of 7.7%. The triangular cross-section hydraulic diameter underwent a shrinkage of 15.2% and 5.3% in terms of the reduction in angle between adjacent side alloys. Experiments were conducted for Reynolds numbers between 50 and 275 with nanofluids containing graphene and Al2O3 nanoparticles in water/water +10% ethylene glycol; these were compared with their respective base fluids. The Poiseuille number indicated that flow was laminar developed with base fluid and laminar developing with nanofluid as coolant. Despite providing the lowest thermal resistance, the graphene nanoparticles in water created the greatest pressure drop leading to a reduced performance coefficient. Al2O3 nanoparticles in water/water +10% ethylene glycol were found to have 7.7% and 20% better performance coefficients than their respective base fluids.

Machinability of Inconel 718 using unitary and hybrid nanofluids under minimum quantity lubrication

ABSTRACT In the current study, unitary and hybrid nanofluids are used with minimal lubrication to examine Inconel 718’s machinability. Nanofluids are obtained by dispersing unitary and mixed amounts of aluminium oxide, multi-walled carbon nanotubes, and graphene nanoparticles into palm oil. Initially, turning experiments were performed with pure palm oil and different unitary and hybrid nanofluids using differently coated carbide tools to obtain the best combination of the type of nanofluid(s) and coated tool for the lowest tool wear. Further, the cutting forces, surface roughness, chip thickness ratio, chip morphology, and shear angle were obtained, varying with the cutting parameters for the best combination of nanofluid(s) and the tool. The analysis of worn-out tools has been performed through images captured using optical and scanning electron microscopes. The study indicates that aluminium titanium nitride-coated tools outperform titanium aluminium nitride-coated tools with hybrid aluminium oxide and multi-walled carbon nanotube-based nanofluid, followed by a unitary aluminium oxide-based nanofluid. It could be attributed to the higher thermal conductivity and surface tension of aluminium oxide nanoparticles and the better lubricating and cooling capabilities of multi-walled carbon nanotubes. Comparatively lower performance was observed with graphene-based nanofluid due to severe agglomeration that adversely affected the homogeneity of the fluid.