Titania Nanofluids Research Articles

Numerical Investigation of Thermal Performance Enhancement in a Newly Designed Shell and Tube Heat Exchanger using 〖"TiO" 〗_"2" Nanofluids

This study investigates the use of titanium dioxide (TiO2) nanofluids to enhance the thermal performance of shell and tube heat exchangers. A comparative computational fluid dynamics (CFD) analysis is conducted using water and a 0.5% TiO2 nanofluid. The heat exchanger is modelled using computer-aided design (CAD), with dimensions closely resembling commercial units. The CFD model is validated through a grid-independence study, with a mesh of 4,112,679 elements yielding grid-independent results. The key findings show that the 0.5% TiO2 nanofluid increases the cold fluid outlet temperature by 11.44% compared to water (36.04°C vs. 33.63°C). The average heat transfer coefficient is enhanced by 12.3% when using the nanofluid. The CFD results are consistent with experimental data, with a maximum deviation of 4.2% in the outlet temperatures. This study demonstrates the successful integration of TiO2 nanofluids with an optimized shell and tube heat exchanger design. The novelty lies in the application of nanofluids to improve the thermal performance of industrial heat exchangers. The presented methodology, combining CAD modelling and CFD analysis, provides a foundation for further optimization and experimental validation of nanofluid-enhanced heat transfer systems.

Cost-effective production of Titania nanoparticles for the modification of transformer insulating oil

Nanofluids are prospective solutions for improving the transformer dielectric strengthby adding nanoparticles to the standard oils used in transformers.Oil-based titania nanofluids are becoming increasingly popular due to their superior insulating qualities and distinctive thermal performance, and they areconsideredas possible replacements in the domains of transformer insulating oils.This paper describes the industrial synthesis of titania nanoparticles for improving the insulating characteristics of virgin oil used in transformers.The titania nanoparticles were analyzed using an X-ray diffractogram (XRD), which revealed a prominent peak at Bragg angle 25O, indicating that the titania nanoparticles were generated in the anatase phase. Fourier transform infrared (FTIR) spectroscopy study endorsed the formation of Ti-O-Ti, Ti-OH, C-H and O-H stretching vibrations at 760 cm−1, 1345 cm−1, 2475 cm−1, and 3646 cm−1 wavenumbers respectively. Field emission scanning electron microscopy (FESEM) and Atomic Force Microscopy (AFM) examinations on the produced titania nanoparticles revealed that the particles had a circular shape with a diameter of 55 nm and an average roughness value of roughly 3.6 nm respectively.The viscosity of the host virgin oil and the nanoparticles-filled nanofluid were examined, and higher viscosity values were found as particle concentration increased.The effective conductivity study with the zeta potential and thermal conductivity fluctuation with temperature variation also revealed that at higher temperatures, conductivity with the zeta potential increased and thermal conductivity dropped. Furthermore, the breakdown strength of the titania nanoparticles-based virgin oil was observed to be effectively increased with the particle concentration.

Numerical exploration of electroosmotically regulated squeezing rotating flow of TiO2/water nanofluid in a parallel plate channel under triple diffusion convection

The basic motive of this article gives a rudimentary insight into the triple diffusive convective flow of ionic aqueous solution-based titanium dioxide (TiO2) nanofluid amidst two rotating parallel plates. The lower plate is stationary and permeable, allowing the lateral suction/injection of the fluid, while the upper plate is impermeable and moves towards the lower plate. The fluid flow is explored under the simultaneous implementation of electric and magnetic forces. The presence of axial electric force across the plates with an ionic solution between them generates the electroosmotic phenomenon. The Oberbeck-Boussinesq approximation is utilized to include the solutal buoyancy forces occurring due to the concentration gradient of two different solutes. The appropriate similarity transformation is used to reform the governing equations which are resolved using the built-in numerical solver bvp4c of MATLAB. The computations reveal that velocity in the case of injective flow is larger than in the case of suction through the bottom plate. The forwarding electric field contributes to the primary velocity profile at the lower plate while velocity declines near the top plate. For solutes 1 and 2, the modified Dufour number and Dufour Lewis numbers have an opposing effect on the Nusselt number at the lower and upper plates.

Thermal analysis of nanofluid magnetic flow on a rotating disk in the presence of radiation considering response surface method

This study examines Titania nanofluids that conduct electricity and are combined with various base fluids, focusing on various aspects. A magnetic field analyzes a continuous flow of nanofluid over a rotating disk that is positioned at an angle with a three-dimensional geometry assumption. The continuity, momentum, and energy balance equations are established, transformed using similarity variables, and solved through Akbari–Ganji Method (AGM) and Homotopy Perturbation Method (HPM) semi-analytical methods. The effects of several parameters, such as Magnetic parameter (M), Hall parameter (m), Porosity parameter ([Formula: see text]), Radiation parameter (Rd), and Thickness of liquid ([Formula: see text]), are examined through a graphical representation of state variables, including skin friction and Nusselt number. Additionally, the Response Surface Method (RSM) method has been utilized to simultaneously display the effects of porosity parameters and various factors across the disk. The findings showed that the magnetic, porosity, Hall, and thickness parameters had a significant impact on the behavior of the nanofluid. Specifically, the magnetic field had a strong influence on the velocity and temperature distribution of the fluid as it flowed over the rotating disk, while changes in porosity, Hall, and thickness parameters also affected these state variables.

Influences of blowing and internal heating processes on steady MHD mixed convective boundary layer flows of radiating titanium dioxide‐ethylene glycol nanofluids

AbstractThe present analysis intends predominantly to explore the multiple behaviors of radiating ethylene glycol‐based titanium dioxide nanofluids during their steady boundary layer flows near a vertical permeable surface under the prominent impacts of uniform blowing and nonuniform internal heating processes. By incorporating the dynamical contribution of Lorentz and buoyancy forces in the momentum equation and adopting the single‐phase nanofluid approach along with the constitutive equations of the second‐grade rheological model and Corcione's correlations, the governing partial differential equations and their appropriate boundary conditions are derived mathematically based on the boundary layer theory and other admissible physical approximations. After several simplifications, the aforesaid differential formulation is converted into a set of ordinary differential equations and realistic boundary conditions, which are solved thereafter numerically using GDQ's‐NT method. Moreover, it is demonstrated that the strengthening in the blowing and internal heating processes has a boosting effect on the velocity and temperature profiles. However, the other influencing parameters show dissimilar dynamical and thermal trends. Furthermore, it is witnessed that the mixed convective heat transfer, the viscoelasticity trend of the nanofluidic medium, and the nanoparticles’ loading exhibit an enhancing impression on the surface heat transfer rate.

Nusselt number estimation using a GBR-GSO-based machine learning predictive model in alumina and titania nanofluids in a boiling process

Nusselt number estimation using a GBR-GSO-based machine learning predictive model in alumina and titania nanofluids in a boiling process

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.

Heat transfer analysis of nanofluids for fixed volume fraction of pipe in pipe heat exchanger using CFD

A heat exchanger device having the capability to transfer heat from one source to another. Double pipe heat exchanger (DPHE) has been selected for current study. In this, A metallic solid wall acts as a medium which can separate the two fluids and can transfer the heat though this wall. Nanofluids have higher thermo-physical properties and having high thermal conductivity to enhance the heat transfer. Copper oxide (cuo), silicon oxide (SiO2) and titanium oxide (TiO2) nanofluids are considered to this work. A simulation work is conducted to double pipe heat exchanger to study the heat transfer characteristics. The heat transfer is enhanced 30–40% when temperature maintained at 800C for all mass flow rates. 4–7% and 6–14% high heat transfer coefficient for Cuo nanofluid than TiO2 and SiO2 nanofluids. The global results in this study stating that Cuo nanofluid performed better than TiO2 and SiO2 nanofluids.

Effect of Microwave Irradiation on the Dielectric Characteristics of Semi-Conductive Nanoparticle-Based Nanofluids: Progress towards the Microwave Synthesis.

Studies on dispersing nanoparticles in base fluid to elevate its essential and critical properties have evolved significantly in the recent decade. Alongside the conventional dispersion techniques used for nanofluid synthesis, microwave energy at 2.4 GHz frequency is irradiated onto the nanofluids is experimented with in this study. The effect of microwave irradiation on the electrical and thermal properties of semi-conductive nanofluids (SNF) is investigated and presented in this article. Titanium dioxide and zinc oxide are the semi-conductive nanoparticles used for this study to synthesize the SNF, viz., titania nanofluid (TNF) and zinc nanofluid (ZNF). Flash and fire points are the thermal properties verified, and dielectric breakdown strength, dielectric constant (εr), and dielectric dissipation factor (tan δ) are the electrical properties verified in this study. AC breakdown voltage (BDV) of TNF and ZNF is improved by 16.78% and 11.25%, respectively, more than SNFs prepared without microwave irradiation. Results justify that the synergetic effect of stirring, sonication, and microwave irradiation in a rational sequence (microwave synthesis) exhibited better electrical and unaltered thermal properties. This microwave-applied nanofluid synthesis could be a simple and effective route to prepare the SNF with improved electrical properties.

Magnetohydrodynamic (MHD) Natural Convection Flow of Titanium Dioxide Nanofluid Inside 3D Cavity Containing a Hot Block: Comparative with 2D Cavity

The natural convection of TiO2-Water-Nanofluid in a cubic cavity, containing a hot block under the influence of the magnetic field was studied numerically. The verticals walls are cold, the bottom wall is hot and the other walls (top, front and rear) are adiabatic. This work aims to visualize the importance of taking into account the three-dimensionality of the flow in the presence of magnetic field as well as the impact of the addition of nanoparticles on heat exchange rate evolution. The governing equations are solved using the finite volume method and the SIMPLER algorithm is used for pressure-velocity coupling. The problem was simulated at different Rayleigh numbers (103 ≤ Ra ≤ 106), Hartmann numbers (0 ≤ Ha ≤ 90) and inclination angles of the magnetic field (0 ≤ ω ≤ 135°) as well as nanoparticles volume fraction (φ = 0%, φ = 5%) with fixed Prandtl number (Pr = 7). The thermal conductivity and dynamic viscosity of the nanofluid are estimated by taking into account temperature-dependent properties, using Corcione’s correlations. Based on the cooling optimization of cold walls along with comparative analysis between 3D cavity and 2D cavity, the obtained results show that the buoyancy force enhances the heat exchange, while the magnetic field produces opposite effects. When the buoyancy force is dominated, the intensification of heat transfer becomes large, compared to the case where conduction is dominant. The qualitative difference between a 3D and 2D configuration is remarkable for higher Ra, and becomes smaller when the magnetic field is applied horizontally or vertically with relatively high intensity. But, quantitatively, the 3D flow is far from being considered as a 2D flow for all pertinent parameters control. Finally, adding nanoparticles enhances heat transfer for both configurations, the best transfer rate is obtained for ω = 0.

Investigating flow features and heat/mass transfer in two-layer vertical channel with [formula omitted] hybrid nanofluid under MHD and radiation effects

This study aims to investigate the physical mechanisms of mass and heat transfer of nanofluid and hybrid nanofluid in a two-layer vertical channel. The Casson fluid model is used to depict the non-Newtonian behavior of blood flow (base fluid). The two-layer vertical channel represents a realistic model of blood flow in microvessels, where region-I contains titanium dioxide nanofluid. In contrast, region-II contains hybrid nanofluid of graphene and titanium dioxide. The formulation of the flow model incorporates laminar, incompressible flow with added MHD, viscous dissipation, and radiation effects. Homotopy analysis technique (HAM) is used to solve non-linear ordinary differential equations (ODEs) after the governing equations are converted into nondimensional. The graphical representation of the effect of physical parameters on velocity and temperature is presented, while the variation of skin friction and Nusselt number with emerging parameters is tabulated. The findings of current study are that an increase in the magnetic parameter has a similar effect on both velocity and temperature profiles. The Nusselt number rises with the rising of the Eckert number, Prandtl number, and magnetic parameter at the right wall but drops with the rising of these values at the left wall. Temperature is directly proportional to Eckert and Prandtl numbers, whereas a rise in radiation leads to a drop in temperature. The findings have potential implications for biomedical applications, especially in drug delivery through blood vessels to treat cardiovascular diseases.

Investigation of heat transport characteristics of titanium dioxide nanofluids with corrugated tube

AbstractThe implications of cooling fluids with suspended titanium dioxide nanoparticles in augmenting the heat transfer rate in the heat exchanger are discussed. The application of corrugated tubes for increasing the effectiveness of heat exchangers is studied in this work. In deionized water, the nanofluid is synthesized to get three different volume concentrations (0.25%, 0.5%, and 1%). The nanofluid's flow rate varies to 100 L/h, 150 L/h, and 200 L/h, respectively. An experiment is carried out in three corrugated tubes made of copper, with pitch values of 18, 20, and 25 mm, respectively. Optimization is carried out to determine the influence of nanofluid concentration, the mass flow rate of the nanofluids, and the corrugation pitch over the heat transfer rate. It is concluded that increasing the volume concentration of the nanoparticles in deionized water and the mass flow rate of the nanofluid enhances the heat transfer rate in the heat exchanger.

Prandtl Number and Viscosity Correlations of Titanium Oxide Nanofluids

Prandtl Number and Viscosity Correlations of Titanium Oxide Nanofluids

Thermal performance analysis of a counter-flow double-pipe heat exchanger using titanium oxide and zinc oxide nanofluids

In a nanofluid, metals, oxides, or carbides with a diameter of less than 20 nm are combined as one with a base liquid, like water or an oil. Many examinations have recently been completed to inspect the effect of nanofluid on the speed increase of heat transfer rates in various heat exchangers. Heat transfer improvement using nanofluid is dependent on a variety of factors, among them the kind of nanoparticles, their size, shape, and concentration in the base fluid. The proposed article is aimed to study experimentally how a twin-pipe heat exchanger with counter-flow arrangements and two kinds of nanofluid cooling fluid performed. Zinc oxide (ZnO) and titanium oxide (TiO2) are used as base fluids with ethylene glycol (EG) and alkaline water. This study looked at the heat transfer capabilities of a two-pipe heat exchanger with a counter-flow configuration when various quantities of TiO2 and ZnO nanoparticles were combined with EG alkaline water. Alkaline water and nanofluid nanoparticle volume concentrations were 0.5, 0.75, and 1.25. The constant intake temperatures of 60 °C for water and 30 °C for nanofluid in a heat exchanger result in two fluids running at a constant inflow velocity. It was found that nanofluid had higher heat absorption at low flow rates than EG alkaline water and hence improved heat exchanger thermal performance. It was also noticed that when the concentration of nanoparticles increases, the heat transmission rate increases.

Experimental Investigations on the Performance of Thermosyphon Solar Flat Plate Collector using TiO2 Nanofluids

Titanium dioxide nanofluid is used in the thermosyphon solar flat plate collector at volume fractions of 0.1%, 0.3%, 0.5%, 0.7%, and 1% to test the collector’s effectiveness. The heat transfer coefficient, Nusselt number, friction factor, and pressure drop calculations were used to analyze the impact of adding nanoparticles to the working fluid. The effectiveness of the solar flat plate collector and the heat transfer coefficient are both greatly affected by the addition of titanium dioxide to the working fluid, with a tolerable rise in pressure drop. With concomitant variances of 15% and 13%, correlations were constructed for the Nusselt number and friction factor.

Correlations for specific heat and density of Titanium Oxide Nanofluid at low nanoparticle concentrations

Different observations by researchers have sparked an interest in the study of Nanofluids, which are fluids containing nanometer-sized particles. According to research, these Nanofluids have exceptional thermophysical properties compared to their basal fluids. Recent research has focused on fluids containing molten ions in addition to water, oil, and glycol base fluids, which are the most studied based fluids. In this paper, the specific heat of Titanium Oxide Nanofluids is investigated. In addition, these Nanofluids are compared to their respective reference base fluids, Ethylene Glycol (40%)/Water (60%) base fluid, Ethylene Glycol base fluid, and water base fluids. New correlations for calculating the specific heat and density of nanofluids as functions of temperature are introduced. Then, these new correlations are compared to the available theoretical models in the literature. In comparison to the presented theoretical models, the outcomes demonstrate improved specific heat and density results with new correlations.

Synthesis and characterization of TiO2 nano fluids formation and its optical, electrical and catalytic property analysis

Growing interest in the field of thermal energy conversion into useful electrical energy is the field of interest towards energy harvesting. Titania nanofluid prepared by low cost precursors using hydrothermal method. The physico chemical characterization of as prepared titania nanoparticle were characterized by XRD, Raman and UV-Visible spectrometric methods. The particle size measurement was determined via Zeta potential study. We have studied the miscibility and viscosity and sedimentation property of as prepared titanium dioxide nanofluid particles by low cost method in various mixed solvent medium. Nanofluids property with different concentration of TiO2 nanoparticles (0.01%, 0.02%, 0.04%, 0.05%, 0.1%, 0.2%, 0.5%) have been prepared by adding different concentrations and studied their physico-chemical properties. The as prepared TiO2 nanoparticles in the form fluid solution have shown very clear settled solution after the addition of suitable solvent medium and preparation method.

Modification of insulating oils and oil-based titanium dioxide nanofluids for transformers: a review.

In the last decade, oil-based titanium dioxide nanofluids (TiO2 NFs) have gained immense interest due to their unique insulating properties and excellent thermal performance, which endow them with the potential for application in the field of modified insulating oils. A timely comparison, analysis and summary of recent advances in the preparation, characterization, and properties of different oil-based TiO2 NFs for oil-immersed power transformers will contribute to provide a useful reference for the subsequent development of such materials. Preparation methods are reviewed along with their merits and demerits. Characterization techniques including scanning electron microscopy (SEM), transmission electron microscopy (TEM), optical microscopy (OM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), dynamic light scattering (DLS), Fourier transform infrared (FTIR) spectroscopy, thermally stimulated current (TSC), pulse electroacoustic technique (PEA), finite element analysis (FEA), fluorescence spectroscopy, Raman spectroscopy and zeta potential analysis are all applied to determine the crystal structure, particle size, surface function, surface charge and stability. Stabilization mechanisms are also discussed in detail. Some critical properties of oil-based TiO2 NFs under the application of different influencing factors such as base oils, crystal structure, size of nanoparticles, surface modifiers, mixing percentage, and aging environment are highlighted. Finally, the existing challenges and perspectives are presented for future research.

Thermo-convective behavior and entropy generation studies on Alumina and Titania nanofluids flowing through polygonal ducts

The current study emphasizes the thermal performance of 0.05, 0.1, and 0.2% volume concentrated Al2O3/DI water and TiO2/DI water nanofluids flowing through three different ducts (equilateral triangle, square, and hexagonal shaped) were compared with circular tubes. The thermo-convective experiments were carried out in the turbulent regime (5000≤ Re ≤ 10,000) at iso-heat flux conditions. The experimental outcome reveals that the maximum Nusselt number of 78, 74, and 71 were achieved when 0.2% Al2O3/DI water flowed through hexagonal, square, and triangular ducts, respectively. Similarly, the desired lowest friction factor of 0.03692, 0.03688, and 0.03686 was achieved by the same nanofluid through those orientations, which ensured that the Al2O3/DI water outperformed TiO2/DI water. The maximum Performance Evaluation Criteria (PEC) was 1.102 when comparing the 0.2% Al2O3/DI water nanofluid flow through a hexagonal duct with water through a circular tube, and 1.169 when the flow through the duct is compared with DI water flow through the same hexagonal duct. When evaluating the performance of all these augmented flow orientations by Entropy Performance Evaluation Factor (EPEF), the maximum values of 665, 572, 635, and 654 were achieved by 0.2% Al2O3/DI water and 660, 531, 561, and 628 by 0.2% TiO2/DI water while flowing through the circular tube, triangular, square, and hexagonal ducts, respectively. Correlations for Nusselt number and friction factor employable to these orientations were derived based on the dominant dependant parameters.

Heat Transfer Characteristics of Fullerene and Titania Nanotube Nanofluids under Agitated Quench Conditions.

Distilled water and aqueous fullerene nanofluids having concentrations of 0.02, 0.2, and 0.4 vol % and titania (titanium dioxide, TiO2) nanofluids of 0.0002, 0.002, and 0.02 vol % were analyzed for heat transfer characteristics. Quenching mediums were stirred at impeller speeds of 0, 500, 1,000, and 1,500 RPMs in a typical Tensi agitation system. During the quenching process, a metal probe made of ISO 9950 Inconel was used to record the temperature history. The inverse heat conduction method was used to calculate the spatial and temporal heat flux. The nanofluid rewetting properties were measured and matched to those of distilled water. The maximum mean heat flux was 3.26 MW/m2, and the quickest heat extraction was 0.2 vol % fullerene nanofluid, according to the results of the heat transfer investigation.