Alumina Nanofluids Research Articles

Predicting the thermal performance of screen mesh wick heat pipe with alumina nanofluids using response surface methodology

This study aims to investigate the effect of heat load, tilt angle, and volume concentration of alumina nanofluid on the thermal performance enhancement of cylindrical screen mesh wick heat pipe in terms of thermal resistance(R) and thermal conductivity(k). Response surface methodology based on the Box–Behnken design was implemented to investigate the influence of heat input (100–200 W), tilt angle (0–90°), and volume concentration (0.05–0.25 vol%) of nanofluid as the independent variables. Second-order polynomial equations were established to predict the responses, ‘R’, and ‘k’. The significance of the models was tested by means of analysis of variance (ANOVA). In addition, a correlation between the independent variables was derived in this study. The results revealed that the optimum heat input, inclination angle, and concentration of nanofluid were determined as 200 W, 52.72°, and 0.1773 vol. % respectively for both ‘R’ and ‘k’. SEM analysis was performed to observe the thermal performance phenomena of the heat pipe before and after experimentation.

Laminar Natural Convection of Water-Based Alumina Nanofluids in a Square Enclosure

Steady-state, laminar, natural convection of water-based alumina nanofluids in a square enclosure with partial heating from the bottom and symmetrical cooling from the sides has been investigated based on numerical simulations. The effects of Rayleigh number, normalized heat source length and nanoparticle volume fraction on the heat transfer behavior have been investigated. An increase in Rayleigh number, for given values of normalized heat source length and nanoparticle volume fraction, leads to an increase in Nusselt number. For a given set of values of Rayleigh number based on base-fluid properties and normalized heat source length, the Nusselt number does not vary significantly with increasing nanoparticle volume fraction because the strengthening viscous effects with increasing volume fraction for water-based alumina nanofluids counteracts the enhanced thermal diffusion in nanofluids. However, when effective Rayleigh number is based on nanofluid properties, Nusselt number decreases with increasing nanoparticle volume fraction. For a given set of values of Rayleigh number and nanoparticle volume fraction, the Nusselt number increases with increasing normalized heat source length due to the strengthening of advective transport. A correlation for mean Nusselt number is proposed which adequately captures qualitative and quantitative behavior obtained from the simulations across the considered parameter range.

Lattice Boltzmann simulation of natural convection of ethylene glycol-alumina nanofluid in a C-shaped enclosure with MFD viscosity through a parallel computing platform and quantitative parametric assessment

There has been a strong interest to design and optimise thermally efficient heating and cooling equipment. The conventional fluids such as oil and water have limited thermal efficiency. Therefore, researchers have been seeking alternatives to the conventional fluids to improve the efficacy of heat exchanging and electronic cooling devices and nanofluid has been identified as a great option in this regard. Although nanofluid is a great alternative, certain specifications, geometries, and pertinent parameters need to be thoroughly investigated for a comprehensive understanding with the aid of robust computational technique. The aim of this study was to investigate the multiple-relaxation-time (MRT) lattice Boltzmann method (LBM) to numerically analyse the effects of magnetic field dependent (MFD) viscosity on the natural convection of ethylene glycol (C2H6O2)-alumina (Al2O3) nanofluid in a side heated two-dimensional C-shaped enclosure using graphics processing unit (GPU) by a computing unified device architecture (CUDA) C parallel computing platform. Numerical simulations were performed at multifarious Rayleigh numbers, Hartmann numbers, and the different magnetic field inclination angles to study the heat transfer and various flow patterns under magnetic field-dependent (MFD) viscosity, solutions were presented by varying volume fraction of nanoparticles, Rayleigh numbers, viscous parameters, magnetic inclination angles, and Hartman numbers on streamlines, isotherms, local and average Nusselt number and temperature. Further correlation developments were conducted through Levenberg-Marquardt data-driven algorithm to investigate the influence of all the parameters on average Nusselt numbers, entropy generation, and fluid irreversibility parameter. The findings demonstrated that as the Rayleigh numbers augmented, the average Nusselt number increased significantly due to the influence of buoyancy, whereas under the influence of Hartmann numbers, average Nusselt numbers decreased due to the dominance of magnetic field strength and Lorentz force. However, the heat transfer continued to improve if the concentration of the nanoparticles increased, thus showcasing the importance of hybrid nanofluid. In addition, the entropy generation impact across the cavity for the ethylene glycol-alumina nanofluid was greatly enhanced by a stronger buoyancy influence.

Coaxially swirled porous disks flow simultaneously induced by mixed convection with morphological effect of metallic/metallic oxide nanoparticles

This study focuses on the numerical modeling of coaxially swirling porous disk flow subject to the combined effects of mixed convection and chemical reactions. We conducted numerical investigations to analyze the morphologies of aluminum oxide (Al2O3) and copper (Cu) nanoparticles under the influence of magnetohydrodynamics. For the flow of hybrid nanofluids, we developed a model that considers the aggregate nanoparticle volume fraction based on single-phase simulation, along with the energy and mass transfer equations. The high-order, nonlinear, ordinary differential equations are obtained from the governing system of nonlinear partial differential equations via similarity transformation. The resulting system of ordinary differential equations is solved numerically by the Runge–Kutta technique and the shooting method. This is one of the most widely used numerical algorithms for solving differential equations in various fields, including physics, engineering, and computer science. This study investigated the impact of various nanoparticle shape factors (spherical, platelet and laminar) subject to relevant physical quantities and their corresponding distributions. Our findings indicate that aluminum oxide and copper (Al2O3-Cu/H2O) hybrid nanofluids exhibit significant improvements in heat transfer compared to other shape factors, particularly in laminar flow. Additionally, the injection/suction factor influences the contraction/expansion phenomenon, leading to noteworthy results concerning skin friction and the Nusselt number in the field of engineering. Moreover, the chemical reaction parameter demonstrates a remarkable influence on Sherwood’s number. The insights gained from this work hold potential benefits for the field of lubricant technology, as they contribute valuable knowledge regarding the behavior of hybrid nanofluids and their associated characteristics.

Study on the performance enhancement of ice storage and melting processes in an ice-on-coil thermal energy storage system

Air conditioners equipped with an ice storage system store a large amount of latent heat during the off-peak period at night, and use the stored cold energy for the air conditioner during the peak period of the day, thereby greatly reducing peak power consumption. In this study, an experimental analysis was conducted to evaluate the cold storage and cooling characteristics of an ice-on-coil storage system. Firstly, the influence of the inlet brine temperature, flowrate, and concentration on the discharge rate was studied. It was observed that all parameters were directly proportional to the discharge rate, and the effect of brine inlet temperature was more pronounced. Secondly, the alumina nanofluid as a phase change material was employed in the system for enhancing the thermal performance. The experimental results showed that using nanofluid shortened the freezing time, while it had a negative impact on the thermal behavior during the ice melting. Thirdly, the ice storage coils with spiral fins were used. It was concluded that the employment of finned coils reduced the melting time by 24.0 %, increased the average discharge rate by 74.4 %, and raised the cumulative discharge capacity by 63.5 % compared with original bare coil design.

Wettability Alteration of Limestone Carbonate Cores Using Methylene Blue and Alumina-Based Nanofluid: Implications for EOR

Wettability is a key parameter for optimizing the residual oil recovery from geological rock formations and it provides a path for improved oil recovery and geo-storage of energy. Thus, the key motive behind wettability alteration from hydrophobic to hydrophilic is to enhance the oil productivity. Thus, this work concentrates on Sui main limestone reservoir core samples’ wettability alteration (altering their surface wetting behavior from an oil-wet to water-wet state) for enhanced oil recovery. Hence, we examine the effectiveness of alumina nanofluid as well as a new chemical methyl blue to alter the wettability. Methyl blue is released on a large scale from various industries, i.e., pharma, textile, and food industries, which is a key environmental concern; subsequently, it contaminates the water table. Hence, the study explores the effects of MB and alumina nanofluid on wettability. The effect of nanofluids formulated via dispersing the alumina nanoparticles in aqueous solutions at various concentrations (0. 0.05, 0.3, 0.50, 0.75, and 1.0 wt. %) were tested for wettability modifications under different physio-thermal conditions. Subsequently, the wettability change was examined for these samples treated with different concentrations of MB (10, 15, 30, 50, and 100 mg/L) for 7 days at two different temperatures (25 and 50 °C). The results show that the hydrophobicity of the SML carbonate rock significantly reverses while treating with alumina nanofluids and MB. Thus, the wettability modification/reversal via the treatment of MB and alumina nanofluids can be an effective mechanism for hydrogen injections and EOR processes.

Investigation of the Thermal Performance of Water and Aluminum Oxide Nanofluid as a Coolant for Solar Panels

A solar panel, also known as a photovoltaic (PV) panel, converts photons from sunlight into usable energy. However, panel warming during the day limits voltage production and results in energy-electricity waste. The efficiency of this PV panel's cooling system utilizing water and aluminum oxide (Al2O3) nanofluid was simulated and assessed using Computational Fluid Dynamics (CFD). This research examines the thermal performance of temperature differences between uncooled, water-cooled, and Al2O3 nanofluid-cooled solar panels. To find the lowest temperature of the solar panel achieved, the mass flow rates of coolants (16.5, 33, 66, and 99 L/h) and inlet coolant temperatures (20, 25, 30, 35, and 40 °C) were varied. Al2O3 nanofluid-cooled solar panels at the maximum flow rate and the lowest inlet coolant temperature, 99 L/h and 20℃, respectively, promised the minimum solar panel temperature, which is critical for energy storage. Furthermore, the use of nanofluid coolant assisted in the reduction of 41 to 60% of solar panel temperature. These results shed insight into the capabilities of nanofluid in the coolant system.

Analysis of melting of phase change material inserted a block via impinging turbulent slot jet

PurposeThe purpose of this study is to do a numerical analysis of the jet to a body filled with phase change material (PCM). The melting of the PCM filled body was investigated by the hot jet flow. Four different values of the Reynolds number were taken, ranging from 5 × 103 = Re = 12.5 103. Water, Al2O3 1%, Al2O3 2% and hybrid nanofluid (HNF; Al2O3–Ag mixture) were used as fluid types and the effects of fluid type on melting were investigated. At 60 °C, the jet stream was impinged on the PCM filled body at different Reynolds numbers.Design/methodology/approachTwo-dimensional analysis of melting of PCM inserted A block via impinging turbulent slot jet is numerically studied. Governing equations for turbulent flow are solved by using the finite element method via analysis and system fluent R2020.FindingsThe obtained results showed that the best melting occurred when the Reynolds number increased and the HNF was used. However, the impacts of using alumina-water nanofluid were slight. At Re = 12,500, phase completion time was reduced by about 13.77% when HNF was used while this was only 3.93% with water + alumina nanofluid as compared to using only water at Re = 5,000. In future studies, HNF concentrations will change the type of nanoenhanced PCMs. In addition, the geometry and jet parameters of the PCM-filled cube can be changed.Originality/valueEffects of impinging jet onto PCM filled block and control of melting via impinging hot jet of PCM. Thus, novelty of the work is to control of melting in a block by impinging hot jet and nanoparticles.

Effect of Black Carbon and Alumina Nanofluid on Thermal and Dynamic Efficiency in Upward Spraying Cooling Tower

In cooling water systems, cooling towers play a critical role in removing heat from the water. Cooling water systems are commonly used in industry to dispose the waste heat. An upward spray cooling water systems was especially designed and investigated in this work. The effect of two nanofluids (Al2O3/ water, black carbon /water) on velocity and temperature distributions along reverse spray cooling tower at various concentrations (0.02, 0.08, 0.1, 0.15, and 0.2 wt.%) were investigated, beside the effect of the inlet water temperature (35 ,40, and 45 ͦ C) and water to air flow ratio (L/G) of 0.5, 0.75, and 1. The best thermal performance was found when the working solution contained 0.1 wt.% for each of Al2O3 and black carbon nanoparticles, with a maximum drop in temperature drops (i, e. range) of (16 ͦ C) and (20 ͦ C), respectively. The temperature of the tower's outlet water was decreased as the inlet working fluid increased, and the thermal efficiency declined with the increasing of the L/G by about 5%. However, the drop in the outlet temperature caused by the nanofluid is more than that of pure water at every point by about 6 ͦ C.

Assessment of solar thermal monitoring of heat pump by using zeolite, silica gel, and alumina nanofluid

Assessment of solar thermal monitoring of heat pump by using zeolite, silica gel, and alumina nanofluid

Studies on Evaluation of the Thermal Conductivity of Alumina Titania Hybrid Suspension Nanofluids for Enhanced Heat Transfer Applications.

Extensive investigations were made and empirical relations were proposed for the thermal conductivity of mono-nanofluids. The effect of concentration, diameter, and thermal properties of participating nanoparticles is missing in the majority of existing thermal conductivity models. An attempt is made to propose a model that considers the influence of such missing parameters on the thermal conductivity of hybrid nanofluids. Al2O3-TiO2 hybrid nanofluids have a 0.1% particle volume concentration prepared with distinct particle volume ratios (k - 1:6 - k, k = 1 to 6) in DI water. The samples were characterized, and the size and shape of the nanoparticles were verified. Also, the influence of varying particle volume ratios and the fluid temperature (varying from 283 to 308 K) were examined. 2.4 and 2.1% enhancements were observed in the thermal conductivity of alumina (5:0) and titania (0:5) nanofluids (having 0.1% volume concentration), respectively. Due to the low thermal conductivity of titania nanoparticles, the conductivity of the hybrid solution is above that of titania and below that of alumina nanofluids. An empirical relation for the thermal conductivity of hybrid nanofluids is established and validated considering the individual particle size, volume ratio, and thermal conductivity of particles.

Effect of Carbon Dioxide Injection on Limestone Permeability Damage Induced by Alumina Nanoparticles for Enhanced Oil Recovery Applications

Enhanced oil recovery using nanoparticles is a promising method. However, when injected into a reservoir, nanoparticles can block pores and cause permeability damage. Therefore, enhancing their performance to lower the permeability damage effect is crucial. This study investigated the effect of pH alteration through carbon dioxide (CO2) injection on the permeability damage of limestone caused by an aluminum oxide (α-Al2O3) nanofluid. The methodology involved nanofluid alternating CO2 core flooding experiments by using nanofluids with a pH of 4.5 and 2.8. After core flooding, the permeability damage was calculated as a percentage of the reduction in the original permeability. The results revealed that the permeability damage in the case of nanofluid alternating CO2 injection was 23.23%. In the nanofluid with a pH of 4.5 injection case, the permeability damage was 47.53%. In the 2.8 pH nanofluid injection case, the permeability damage was 31.01%. The retention of nanoparticles was confirmed through scanning electron microscopy and energy dispersive X-ray analysis. Permeability damage could be attributed to the large nanoparticles’ agglomeration size, roughness of pore surfaces, and nanoparticle sedimentation. The results of the study revealed that altering pH through the α-Al2O3 nanofluid alternating CO2 injection can effectively reduce the permeability damage of limestone.

Numerical Investigation on Pool Boiling Heat Transfer of Silica and Alumina Nanofluids

Surface modification through pool boiling of nanofluid is an efficient technique in delaying critical heat flux and attaining high heat flux at lower wall superheat temperature. The method of involving phase interaction, bubble evolving and dynamics phenomenon, and distribution of vapor void fraction altogether is the motivation behind current topic. The present work will contribute to the recovery and reuse of the wastewater and incinerator heat, cooling of high heat flux generating micro-electronics chips, and cooling of fast breeder test reactors. In the present study, the nucleate pool boiling of SiO2/water and Al2O3/water nanofluid are studied numerically and the effect of wall superheat temperature and heat flux on active nucleation site density, bubble departure diameter, and bubble waiting time are studied. The effect of various heater surface material and nanofluid concentration on wall superheat temperature and heat transfer coefficient are also investigated. A two-phase Eulerian approach, heat flux wall-partitioning model, and Rensselaer Polytechnic Institute boiling model are considered to simulate the current model. The pool boiling of nanofluids resulted in the formation of nano-porous layer on heater surface because of microlayer evaporation process that enhanced the heat transfer coefficient and reduced the wall superheat temperature.

Numerical investigation of the magnetohydrodynamic hybrid nanofluid flow over a stretching surface with mixed convection: A case of strong suction

The present work explores the physical aspects of the alumina and silver nanoparticles on the magnetohydrodynamic (MHD) flow of mixed convection micropolar hybrid nanofluid with ethylene glycol + water [Formula: see text] base fluid via stretching surface embedded in a porous medium. A strong magnetic field is employed normally in the flow direction. The behavior of the suction on the presented flow analysis is discussed strongly. Heat transport phenomena are analyzed. The current model’s mathematical modeling is based on higher-order nonlinear partial differential equations, which are then translated into higher-order nonlinear ordinary differential equations using appropriate similarity transformations. The modeled higher-order nonlinear ordinary differential equations are solved using NDSolve technique. The physical significance of the different flow parameters on the velocity, microrotation, and temperature profiles of the hybrid nanofluid are described in a graphical form. In a tabular form, the skin friction coefficients for nanofluid and hybrid nanofluid against various flow parameters are calculated. Some important results from this investigation are demonstrated that the velocity of the hybrid nanofluid is higher for the stretching ratio parameter and it is detected that the suction parameter enhanced the microrotation profile of the hybrid nanofluid. From the comparison, it is noted that the velocity, microrotation, and temperature of the hybrid nanofluid are higher as compared to the velocity, microrotation, and temperature of the alumina nanofluid and silver-nanofluid.

Influence of stearic acid and alumina nanofluid on CO2 wettability of calcite substrates: Implications for CO2 geological storage in carbonate reservoirs

HypothesisAtmospheric CO2 emissions trigger global warming and climate change challenges. Thus, geological CO2 storage appears to be the most viable choice to mitigate CO2 emissions in the atmosphere. However, the adsorption capacity of reservoir rock in the presence of diverse geological conditions, including organic acids, temperature, and pressure, can cause reduced certainty for CO2 storage and injection problems. Wettability is critical in measuring the adsorption behavior of rock in various reservoir fluids and conditions. ExperimentWe systematically evaluated the CO2-wettability of calcite substrates at geological conditions (323 K and 0.1, 10, and 25 MPa) in the presence of stearic acid (a replicate realistic reservoir organic material contamination). Similarly, to reverse the effects of organics on wettability, we treated calcite substrates with various alumina nanofluid concentrations (0.05, 0.1, 0.25, and 0.75 wt%) and evaluated the CO2-wettability of calcite substrates at similar geological conditions. FindingsStearic acid profoundly affects the contact angle of calcite substrates where wettability shifts from intermediate to CO2-wet conditions, reducing the CO2 geological storage potential. The treatment of organic acid-aged calcite substrates with alumina nanofluid reversed the wettability to a more hydrophilic state, increasing CO2 storage certainty. Further, the optimum concentration displaying the optimum potential for changing the wettability in organic acid-aged calcite substrates was 0.25 wt%. The effect of organics and nanofluids should be augmented to improve the feasibility of CO2 geological projects at the industrial scale for reduced containment security.

Combined Utilization of Cylinder and Different Shaped Alumina Nanoparticles in the Base Fluid for the Effective Cooling System Design of Lithium-Ion Battery Packs

It is important to consider the thermal management of lithium-ion batteries to overcome their limitations in usage and improve their performance and life cycles. In this study, a novel cooling system for the thermal management of lithium-ion battery packs is proposed by using an inner cylinder in the cooling channel and different-shaped nanoparticles in the base fluid, which is used as the cooling medium. The performance improvements in a 20 Ah capacity battery are compared by using a water–boehmite alumina (AlOOH) nanofluid, considering cylinder-, brick-, and blade-shaped nanoparticles up to a solid volume fraction of 2%. The numerical analysis is conducted using the finite element method, and Reynolds numbers between 100 and 600 are considered. When the efficacy of the coolants utilized is compared, it is apparent that as the Reynolds number increases, both cooling media decrease the highest temperature and homogenize the temperatures in the battery. The utilization of the cylinder in the mini-channel results in a 2 °C temperature drop at Re = 600 as compared to the flat channel. A boehmite alumina nanofluid with a 2% volume fraction reduces the maximum temperature by 5.1% at Re = 200. When the shape effect of the nanofluid is examined, it is noted that the cylinder-shaped particle improves the temperature by 4.93% as compared to blade-shaped nanoparticles and 7.32% as compared to brick-shaped nanoparticles. Thus, the combined utilization of a nanofluid containing cylindrical-shaped nanoparticles as the cooling medium and a cylinder in the mini-channel of a battery thermal management system provides an effective cooling system for the thermal management of the battery pack. The outcomes of this work are helpful for further system design and optimization studies related to battery thermal management.

Analysis of tool wear and chip morphology under different machining environments in turning operation

A large supply of coolant can raise machining costs and be potentially harmful to the environment. Therefore, other techniques are needed to solve the issues that arise while using coolant. In this study, the effects of cutting speed, feed, depth of cut, and lubrication conditions (dry: no lubrication, cotton seed oil-based nano fluid: alumna is used during machining). The surface roughness and cutting force were investigated during the turning of 304 stainless steels with minimum quantity lubrication (MQL). L9 orthogonal array was used for the experiments. The findings show that dry may be replaced by alumina nanofluids with MQL. In order to assess the machinability of hardened AISI 304 steel, cutting force and surface roughness are taken into account as technological performance criteria. Al2O3 is combined with cotton seed oil for creating nanofluid sample.

The Effect of Quenching in Different Concentrations of Alumina Nano Fluids on Overall Properties of Al-6061

The Effect of Quenching in Different Concentrations of Alumina Nano Fluids on Overall Properties of Al-6061

Pool Boiling Heat Transfer Characteristics of New and Recycled Alumina Nanofluids

This paper reports an experimental investigation of the heat transfer features of new and recycled Alumina (Al2O3) nanofluids (NFs) in the pool boiling (PB) system. The mixture of ethylene glycol (EG) and distilled water (DW) is selected as the base fluid (BF), and NFs samples of two low concentrations (0.01 and 0.05 vol.%) of Al2O3 nanoparticles were prepared. Furthermore, the characteristics of the prepared NFs are evaluated to investigate the heat transfer performance as well as the reusability of the NFs for long-term applications and recycling consideration. Although there have been a large number of boiling studies with NFs, the current study is the first of its kind that addresses the mentioned operation conditions of recycling NF samples. The results are compared with the relevant BF in terms of properties, critical heat flux (CHF), burnout heat flux (BHF), and the convection coefficient of the Al2O3 NFs in the PB system. The results showed good enhancements in both CHF and BHF of these NFs yielding up to 60% and 54% for BHF at 0.05 vol.%, respectively. The reusage of the previously used (recycled) Al2O3 NF showed a considerable increase in heat transfer performance compared to base fluids but slightly lower than the newly prepared one. The results of the reused nanofluids demonstrate the great prospects of their recyclability in heat transfer systems and processes such as in pool boiling.

Machining of nickel-based super alloy inconel 718 using alumina nanofluid in powder mixed electric discharge machining

Inconel 718 is a nickel-based superalloy with exceptional mechanical qualities, including high tensile and impact strength, as well as good oxidation and corrosion resistance. EDM is widely used to cut hard materials of this type by common parameters affecting spark, current, duty cycle etc, whereas MRR, SR can be greatly improved by using sufficient fluid properties of the dielectric. Incorporation of alumina nanoparticles with deionized water may improve machining performance, with no prior research on machining characteristics of Inconel 718 using alumina nanofluid in EDM. The machinability of Inconel 718 via the electrical discharge machining process, as well as the performance of alumina nanofluid as a dielectric medium, have been evaluated using deionized water with a concentration of 0.5%. In this study, based on the effect of various input parameters such as and on the MRR, TWR and SR, and the RSM has been used to conduct the experiments. A maximum MRR of 0.048 g min−1, a TWR of 0.00632 g min−1 and an SR of 3.271 μm are achieved. Overall, the use of alumina nanofluid can improve machining performance in EDM, due to the reduction of abnormalities such as crack formation and molten metal debris in the machined surface of Inconel 718.