Nanolayer Thickness Research Articles

Computational study on entropy generation in Casson nanofluid flow with motile gyrotactic microorganisms using finite difference method

The present study reveals the phenomenon of flow and thermal variations of non-Newtonian nanofluids flow of Copper (Cu) nanoparticles through two orthogonal permeable porous discs. Additionally, the study delves into the significance of liquid solid interfacial layer and nanoparticle diameter is studied to optimize the thermal conductivity. Gyrotactic Microorganisms are also considered to optimize the nanoparticles stability inside the fluid, and the entropy generation caused to system disorder, so entropy analysis is also calculated. Using appropriate dimensionless variables, the controlling PDEs are converted into dimensionless forms. These dimensionless PDEs are solved using the Finite Difference technique, which yields very accurate and stable solutions. Higher values of the Rayleigh bio-convection and mixed convection terms enhance the flow velocity field in both porous discs. The less thickness of nanolayer has significance effect to optimize the temperature. Enhancing the values of bioconvection Lewis number leads to a decrease in motile microorganism concentration in both permeable discs, and entropy generation rate increases against rising power of Eckert number and thermal radiation rise. The finite difference method outcomes have been thoroughly validated against already published research, and showing an excellent correlation. This research holds significant potential for applications in the fabrication and electromagnetic control of advanced magnetic nanofluid materials, relevant to biomedical, energy, thermal management, and aerospace technologies.

ZnO/Organic superlattice with phase composite structure for enhanced thermoelectric performance at low temperature

Semiconducting metal oxides, such as zinc oxide (ZnO), are gaining recognition for thermoelectric applications due to their temperature stability, availability, eco-friendliness, and cost-effectiveness. However, ZnO faces challenges in achieving high ZT value due to its low carrier concentration and high thermal conductivity. Traditional methods, like doping and defect engineering, have shown limited success in overcoming these challenges. In this study, we introduce a unique superlattice structure with a phase-composite composition that significantly decreases thermal conductivity through enhanced phonon scattering while maintaining the power factor by inducing new resonant conducting states near the mobility edge. By optimizing nanolayer thickness and doping concentration, we achieved a remarkable power factor of 14.6 μW cm−1 K−2 and reduced thermal conductivity to ∼1.97 W m−1 K−1 at room temperature in samples with 6 nm-thick ZnO nanolayers fabricated at 100 °C. This leads to a ZT value of ∼0.22 at 300 K, the highest among metal oxide thermoelectric materials at low temperatures, which further increases to ∼0.55 at 510 K. These findings demonstrate the potential of hybrid superlattices for efficient low-temperature thermoelectric applications.

Engineered Core-Shell SiC@SiO2 Nanofibers for Enhanced Electromagnetic Wave Absorption Performance.

To enable SiC material to achieve high electromagnetic wave (EMW) absorption performance, solving its impedance mismatch with EMW is necessary. Therefore, a novel approach is proposed for the precise control of impedance matching by adjusting the shell thickness of SiO2 nanolayers on the surface of SiC nanofibers (NFs). High-angle annular dark field-scanning transmission electron microscopy (HAADF-STEM) reveals the atomic scale oxidation process of SiC, providing fresh insights into the oxidation mechanism. By oxidizing to construct a heterogeneous core-shell structure nanofiber (NF) can effectively lock the incident EMW inside the NF through the generated charges gathered at the interface, forming an electronic barrier that prevents the outward propagation of EMWs. The produced SiC@SiO2 NFs-3 exhibits exceptional EMW absorption properties, including an impressive minimum reflection loss (RLmin) of -53.09dB and a broad maximum effective absorption bandwidth (EABmax) of 8.85GHz. These findings not only deepen understanding of the oxidation mechanism of SiC but also offer valuable insights for further enhancing the EMW absorption capabilities of SiC materials, paving the way for their application in advanced EMW technologies.

Refractory high entropy TiTaZrHfW-N/Si3N4 nano-layered alloy thin film’s oxidation resistance

Refractory high entropy TiTaZrHfW-N/Si3-N4 nano-layered alloy thin films are investigated to study the effect of nano-layered architecture and silicon (Si) mean content on their structural, mechanical, thermal properties and oxidation behavior. The films are deposited using direct current (DC) magnetron sputtering of separate Si and TiTaZrHfW targets. The Si mean content is controlled by tailoring the power discharge applied to the Si target. The deposition process led to a nano-layered architecture where Si3N4 (amorphous) and TiTaZrHfW-N (nano-crystalized NaCl FCC type structure) are alternated. By increasing the thickness of Si3N4 nano-layers, the Si mean content increases. All coatings are found to have good thermal stability after annealing under vacuum at 900 °C. Increasing Si mean content reduces the film’s hardness; however, the annealing treatment at 900 °C improves it. A super-hardness of 41 GPa is found for the post-annealed Si-free film. Si3N4 nano-layers enhance the oxidation resistance at elevated temperatures of 600, 700, and 800 °C. This oxidation resistance is further enhanced by increasing the nano-layer’s period and also by increasing the density of the films.

Oxidation Performance of Nano-Layered (AlTiZrHfTa)Nx/SiNx Coatings Deposited by Reactive Magnetron Sputtering.

This work uses the direct current magnetron sputtering (DCMS) of equi-atomic (AlTiZrHfTa) and Si targets in dynamic sweep mode to deposit nano-layered (AlTiZrHfTa)Nx/SiNx refractory high-entropy coatings (RHECs). Transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) are used to investigate the effect of Si addition on the oxidation behavior of the nano-layered coatings. The Si-free nitride coating exhibits FCC structure and columnar morphology, while the Si-doped nitride coatings present a FCC (AlTiZrHfTa)N/amorphous-SiNx nano-layered architecture. The hardness decreases from 24.3 ± 1.0 GPa to 17.5 ± 1.0 GPa because of the nano-layered architecture, whilst Young's modulus reduces from 188.0 ± 1.0 GPa to roughly 162.4 ± 1.0 GPa. By increasing the thickness of the SiNx nano-layer, kp values decrease significantly from 3.36 × 10-8 g2 cm-4 h-1 to 6.06 × 10-9 g2 cm-4 h-1. The activation energy increases from 90.8 kJ·mol-1 for (AlTiZrHfTa)Nx nitride coating to 126.52 kJ·mol-1 for the (AlTiZrHfTa)Nx/SiNx nano-layered coating. The formation of a FCC (AlTiZrHfTa)-Nx/a-SiNx nano-layered architecture results in the improvement of the resistance to oxidation at high temperature.

Structure and optical properties of Si thin film improved by metal Cd nanolayers

Enhancing the characteristics of amorphous semiconductor thin films is imperative for a multitude of applications. The present study examines the impact of Cd nanolayers deposited on a thin film of amorphous Si. The X-ray test showed that the thin silicon film had less of an amorphous structure after a nanolayer of cadmium was added. There has also been the appearance of new phases, and as the thickness of the Cd nanolayer increases, so does the intensity of these phases. Using a field emission scanning electron microscope, it was seen that nanoparticles were developed and subsequently transformed into clusters as the thickness of the Cd nanolayer grew. The absorbance was maximized at 750 nm and near-infrared region after depositing Cd nanolayers, while transmittance was reduced, especially at 100 nm thicknesses. The energy gap was reduced, with a decrease from 5.1 to 1.8 electron volts (eV). However, an increase in the band tails was also noted, rising from 0.7 to 4.9 eV. An increase in the values of the refractive index (n) and extinction coefficient (k) was observed following the deposition of Cd nanolayers of different thicknesses.

Unravelling the Photoelectrochemical Water Splitting of Nanometer-Thick Carbon Nitride Layer.

Matching the thickness of the graphitic carbon nitride (CN) nanolayer with the charge diffusion length is expected to compensate for the poor intrinsic conductivity and charge recombination in CN for photoelectrochemical cells (PEC). Herein, the compact CN nanolayer with tunable thickness is in situ coated on carbon fibers. The compact packing along with good contact with the substrate improves the electron transport and alleviates the charge recombination. The PEC investigation shows CN nanolayer of 93nm-thick yields an optimum photocurrent of 116µAcm-2 at 1.23V versus RHE, comparable to most micrometer-thick CN layers, with a low onset potential of 0.2V in 1m KOH under 1 sun illumination. This optimum performance suggests the electron diffusion length matches with the thickness of the CN nanolayer. Further deposition of NiFe-layered double hydroxide enhanced the surface water oxidation kinetics, delivering an improved photocurrent of 210µAcm-2 with IPCE of 12.8% at 400nm. The CN nanolayer also shows extended potential in PEC organic synthesis. This work experimentally reveals the PEC behavior of the nanometer-thick CN layer, providing new insights into CN in the application of energy and environment-related fields.

Exploring the influence of nanolayer morphology on magnetized tri-hybrid nanofluid flow using artificial neural networks and Levenberg–Marquardt optimization

This study investigates the impact of morphological nanolayers on the thermal conductivity of magnetized tri-hybrid nanofluid flow using artificial neural networks (ANNs) employing the Levenberg–Marquardt (LM-ANN) scheme. Nonlinear partial differential equations (PDEs) are transformed into nonlinear ordinary differential equations (ODEs) using similarity variables. A dataset covering various parameters such as nanolayer thickness, particle radius, magnetic parameter, expansion/contraction ratio, Schmidt number, volume fraction, and Prandtl number is generated using the Bvp5c numerical algorithm. LM-ANN is then used for testing, training, and validation to analyze approximate solutions for individual cases. Histogram analysis, mean square error (MSE), and regression investigations validate the LM-ANN. The proposed approach closely aligns with suggested and reference findings, showing an accuracy level within 10−10 range. Increasing nanolayer thickness leads to higher effective thermal conductivity. The Nusselt number increases notably with higher hybrid nanoparticle volume fraction. Laminar shape consistently exhibits superior heat transfer performance compared to other shapes. Increasing nanoparticle volume fraction enhances the Nusselt number and reduces skin friction coefficients (SFC). Industry recommendations include integrating nanolayer technologies for improved thermal efficiency.

Nanosheet thickness control of nitrogen-doped polyimide/ammonium phosphotungstate composite for photocatalytic mineralization of imidacloprid

A series of polyimide/ammonium phosphotungstate composite photocatalysts were prepared by varying the the amine monomers, including melamine (MAPIPW), melem (MEPIPW), and carbon nitride (CNPIPW). As the heterocycle in these molecules gets larger, the nano-layer thickness reduces progressively. This results in an increased specific surface area for those photocatalysts possessing thin layers. For instance, the specific surface areas recorded for MAPIPW, MEPIPW and CNPIPW are 8.1863, 51.3379, and 142.6756 m2/g respectively. Thanks to their high surface areas, these composites exhibited improved substrate adsorption and demonstrated significant enhancement in imidacloprid degradation rates increasing to 70.06%, 76.39%, and 71.39% for MAPIPW, MEPIPW, and CNPIPW respectively. MEPIPW exhibited the highest degradation efficiency due to its superior physical adsorption, besides exhibiting excellent photovoltaic properties. An intricate POM-π interaction exists between polyimide and the Keggin structure of ammonium phosphotungstate, extending ligand conjugation to this framework so as to disperse electrons across the hybrid material's backbone. Nonetheless, this interaction may be weakened with reduced nano-sheet thickness, impacting composite photon absorption ability. Further enhancing photocatalysis was possible via nitrogen doping using urea, resulting in degradation rates of 93.69%, 95.13%, and 91.39%, for MAPIPW-20%U, MEPIPW-20%U and CNPIPW-20%U respectively.

Tailoring the Brønsted acidity of Ti-OH species by regulating Pt-TiO2 interaction.

Bifunctional catalysts comprising metal and acid sites are commonly used for many reactions. Interfacial acid sites impact intermediate reactions more than other sites. However, controlling the type and amounts of interfacial acid sites by regulating metal-support interaction (MSI) via traditional methods is difficult. Thus, the influence of MSI on interfacial acid sites remains unclear. We prepared Pt-mTiO2/α-Al2O3 (m represents the cycle number of TiO2) catalysts via atomic layer deposition (ALD). New Brønsted acid sites were generated via Pt-TiO2 interaction, and the acidity was precisely regulated by regulating Pt-TiO2 interaction by changing the TiO2 nanolayer thickness. We chose levulinic acid (LA) hydrogenation as a model reaction. The catalytic activity varied with the TiO2 nanolayer thickness and was linearly correlated with the Ti-OH species (Brønsted acid) content. Pt-40TiO2/α-Al2O3, with the highest acid site content of 0.486 mmol/g, exhibited the best catalytic activity. Hydrogen spillover and water dissociation at the Pt-TiO2 interface promoted Ti-OH species generation.

Influence of multilayer nanoarchitecture on phase transformations in the Ti-Cr-Zr system

Nanocrystalline thin films find extensive applications due to their high mechanical strength and wear resistance. However, the challenge is to prevent unwanted grain growth during operation, especially at high temperatures, due to the increased grain boundary volume, which elevates the system's overall energy. Addressing this issue necessitates identifying optimal heat treatment conditions and selecting appropriate chemistry to stabilize grain boundaries. This study investigates the grain growth and phase evolution within Ti-Cr-Zr magnetron sputtered nano multilayers with 5 and 10 nm individual layer thickness, subjected to vacuum heat treatment at 1100 °C for 5 and 10 min. Characterization involved X-ray Photoelectron Spectroscopy (XPS), X-Ray Diffraction (XRD), and Transmission Electron Microscopy (TEM). During deposition, evidence of diffusion was observed as the multilayers formed Cr4TiZr, TiCr2, and Cr2Zr, phases. The Ti-Cr-Zr nanoscale system multilayers with 10 nm individual layer thickness also exhibited the emergence of Ti0.3Zr0.7 phase. During heat treatment grain growth occurred, after 10 min an average grain size of 173.7 nm and 119.1 nm was noted for the Ti-Cr-Zr nanoscale system multilayer with 5 nm and 10 nm individual layer thickness, respectively. The different growth rates are attributed to their distinct interfacial volumes, influencing the reaction velocity due to the variations in nano-layer thickness. No new phases were formed after heat treatment for the case of 10 nm individual layer thickness coating. However, 5 nm individual layer coatings showed the emergence of Ti0.3Zr0.7 phase, not present after deposition. In conclusion, this research achieved the desired nano grain stabilization of the Ti-Cr-Zr system nanoscale multilayers after heat treatment at 1100 °C for 10 min. This process led to the complete decomposition of the multilayer structure, resulting in the formation of grains smaller than 200 nm, marking a significant step toward the effective control of grain growth in nanocrystalline materials.

Giant Raman radiation from molecules in a spherical metal shell

The work considers an electrodynamic model of radiation from molecules placed in a metal shell. The model qualitatively describes the enhancement of the surface-enhanced Raman scattering (SERS) signal from spherical nanoparticles coated with a thin silver film. The change in the SERS signal is calculated depending on the thickness of the metal nanolayer on top of the spherical particles. The radiating molecular dipole interacts with the metal shell and excites surface plasmons. Plasmonic oscillations reach a maximum when the frequency of the dipole is close to the plasmon resonance of the metal shell, and the dipole itself is close to the plasmonic shell. It has been theoretically shown that the intensity of secondary radiation generated by spherical nanoparticles coated with a silver film several nanometers thick can reach up to six or more orders of magnitude. The effect of a tenfold amplification of the SERS signal was experimentally demonstrated using the example of a large ensemble of single polystyrene microspheres with an average diameter of about 300 nm, coated with a silver nanolayer, which have characteristic Stokes frequencies of 1001 cm-1, 1602 cm-1. We believe that the tenfold enhancement of Raman scattering is due to the electromagnetic amplification mechanism.

ВПЛИВ ОПТИЧНОГО СКЛА ЯК ПІДКЛАДКИ В ППР-СЕНСОРАХ НА ТЕМПЕРАТУРНУ СТАБІЛЬНІСТЬ РЕЗУЛЬТАТІВ ВИМІРЮВАННЯ

The influence of the properties of the substrate made from optical glass of surface plasmon resonance (SPR) sensors on the temperature stability of measurements at a temperature change from 20 to 30°C, in which research is most often carried out, was studied. The phenomenon of surface plasmon resonance is very sensitive to any changes at the metal-dielectric interface, so studying the influence of the temperature factor is an actual task. Research in the infrared region of the spectrum is important because in this case the possible thickness of the research object increases, and it is also possible to reduce the thickness of the gold layer that is sprayed to the glass substrate of the sensory element from 50 nm to 30 nm. But heating the sensitive element with an IR laser can introduce an additional error into the measurement results. The sensitive element of the SPR device consists of a plate made of optical glass and a thin layer of gold deposited on it. It is known that materials expand when heated. The difference in temperature coefficients of linear expansion of glass and gold applied to it can lead to unequal expansion of glass (74x10 -7 ) and gold (14.2x10 -6 ), respectively, causing elastic stresses in the gold sensitive layer of the sensor. Sensory elements with a 30 nm gold layer are used for the IR range of measurements, and 50 nm for the visible range. Therefore, we investigated the stability of the results of measuring the angle of surface plasmon resonance minimum at a wavelength of 650 nm (Plasmon-6 device). It was determined that the optical glass of the substrate affects the stability of measurements of the SPR index of air from temperature fluctuations. The period of stabilization of measurement results in the visible range when the temperature changes from 20 to 30 °C to the change in the angle of the SPR minimum changes from 0.0006 degrees/min for Zerodur to 0.0032 degrees/min for flints, i.e. almost 5 times with the thickness of the gold nanolayer 50 nm, and for a thickness of 30 nm it varies from 0.0010 deg/min for crowns and quartz to 0.0013 deg/min for flints. The lowest value corresponds to Zerodur substrates with practically zero temperature coefficient of linear expansion and quartz in this temperature range. To ensure the stability of the results of measurements of SPR characteristics against temperature fluctuations in the range of 20-30°С, it is recommended to use Zerodur, quartz and crowns for the substrates of SPR sensors

Numerical analysis on thermal control and irreversibility for 3D Casson hybrid nanofluid flow within two permeable stretching surfaces with interfacial nanolayer thickness and slip velocities

During the preparation of nanoparticles, the nanolayer thickness plays a vital role in further controlling the flow and thermal–physical features of the fluid. Features are observed to be more prominent in the presence of hybrid nanomaterials. In the present problem, the concomitant effects of the interfacial nanolayer of nanomaterials MWCNT and Fe 3 O 4 during a 3D Casson hybrid nanofluid flow between two parallel plates have been investigated. An appropriate transition is applied to rationalize the substantially paired and nonlinear governing equations. Equations after similarity transformation are processed by concerning the finite element method. Impressions of different governing parameters on the governing systems in conjunction with entropy and the Bejan number are displayed through graphs and tables. Graphs are drawn with an evaluation of general and hybrid nanofluids and different nanolayer thicknesses of nanoparticles. Three-dimensional features were observed for skin friction and the rate of heat transfer. The thermal impact is very significant in the presence of nonlinear thermal radiation and a heat source. After simulation, it is indicated that heat transfer rate disrupts with Biot number while it upgrades with heat generation. The entropy of the system is restricted with an increase in the magnetic and Brinkman numbers, while the Bejan number shows the opposite behavior with respect to those parameters. With an increase in the interfacial nanolayer thickness, the entropy of the system slows down.

An approach to characterize the nanolayer for a nanofluid: Thickness, density and molar mass

The aim of this work is to develop a theoretical approximation to calculate the effective thickness, density and molar mass of the interfacial nanolayer around nanofluid particles. These properties of the nanolayer depend, in general, on temperature, on the nature of the base fluid, the nature of nanoparticles, their geometry and their concentration. The model takes into account all these parameters. This is presented for a general geometry and it is shown that the effective nanolayer molar mass is equal to that of the base fluid. Then, this is particularized for a spherical geometry, which is one of the most usual in literature, and is numerically applied to the aqueous alumina (15 nm) nanofluids at different temperatures and nanoparticle concentrations. The obtained results together with those from the application of the model to some nanofluids from literature, at different temperatures and nanoparticle concentrations, allow providing a general insight into the effective behavior of those nanolayer properties. Finally, it is shown that the model, under its hypothesis, does not support the equation of Pak and Cho except as an approximation.

Thermal Performance of Autocatalytic Chemical Reaction for Hybrid Nanomaterial Fluid Flow

The mass and heat transfer in hybrid magnetohydrodynamic (MHD) nanofluids is controlled by an autocatalytic chemical mechanism, which is the subject of the current study's thorough analysis. The focus of the work is on the nanolayers at interfaces, which link nanoparticles with the supporting fluids and enable coupled mass and heat transfer phenomena.To further investigate its effects, a uniform transverse magnetic field is added to the study.By using similarity methods, the governing nonlinear coupled partial differential equation that describes this sophisticated system is converted into a collection of ordinary differential equations (ODEs). Two numerical approaches( Bvp4c) and the Shooting method, are used to solve the ODEs in order to get precise answers and do a comparison study. One interesting finding about the improvement of thermal performance is that a rise in nanolayer thickness (between 1 and 4) considerably adds to the enhancement. Additionally, it is discovered that improvements in the chemical reaction parameter, which ranges from 0.15 to 0.27, cause the Sherwood number to rise.It is noteworthy that the results of this study add to a better understanding of the complex interactions between magnetohydrodynamics, chemical processes, and nanofluid dynamics. The numerical techniques used highlight the significance of accurate mathematical modeling in illuminating the complexity of such systems. In addition to strengthening the theoretical foundation, this study offers useful information that could have an impact on heat transfer and nanofluid technology applications.

Thermo-solutal Marangoni convective Darcy-Forchheimer bio-hybrid nanofluid flow over a permeable disk with activation energy: Analysis of interfacial nanolayer thickness

Abstract The Marangoni convective phenomena have a unique impact on industries and medical tools. These phenomena are more prominent in the presence of dual nanoparticles (NPs) over base fluids such as blood that are surrounded by a thin interfacial nanolayer, an important feature to control the physical and thermal properties of the NP. In this problem, we have analysed the thermo-solutal Marangoni convective Darcy-Forchheimer flow of nanomaterials with the impact of the interfacial nanolayer. The results of the system of an exponential heat source, non-linear radiation, joule heating, and activation energy are discussed. An appropriate transition is applied to rationalise the substantially paired and nonlinear governing equations and then processed by the Galerkin finite element method (G-FEM). The impression of different governing parameters on the governing systems in conjunction with entropy and Bejan number is demonstrated through graphical and tabular form. Graphs are drawn with an evaluation of general and hybrid nanofluids (HNFs) and different nanolayer thicknesses of NPs. Activation energy and chemical reaction parameters restrict the Sherwood number, and the same is observed for the Nusselt number with an increase in the Brinkman and Eckert numbers. The thickness of the interfacial nanolayer of the NPs restricts the entropy generation of the system, while the entropy is higher for the HNF than the nanofluid. An opposite feature was observed for the Bejan number.

Significance role of dual porosity and interfacial nanolayer mechanisms on hybrid nanofluids flow: A symmetry flow model

The investigation of heat and mass transfer between two porous disks containing porous media is the focus of this paper. In this research, (Ag–Al2O3/water)-based hybrid nanofluid is used. Governing partial differential equations are converted to nonlinear ordinary differential equations by similarity transformations. Numerical solutions to nonlinear systems of equations are achieved using the shooting technique. It is examined how the particle’s diameter and nanolayer thickness affect the thermal conductivity of a hybrid nanofluid. Due to the increment of nanolayer thickness, the Nusselt number increases and vice versa for the radius of the particle. Tables and graphs show how the governing parameters influence velocity, temperature, and mass concentration profiles, as well as physical quantities such as skin friction coefficient and Nusselt number. As the values of the porous medium parameters ([Formula: see text]–13) and nanolayer thickness ([Formula: see text]–12) elevate, the flow of skin friction coefficient and Nusselt number escalate in both porous disks. Moreover, as the values of the particle radius ([Formula: see text]% to 12%) and Reynolds number ([Formula: see text]1 to 2) amplify, the flow of heat transfer rate is diminished in the lower disk. Porous materials have a high surface area, which increases the contact area between the nanofluids and the porous medium. Porous materials can enhance the permeability of the fluid, reducing the pressure drop in the system. This can be advantageous in applications where high flow rates and low-pressure drops are desired, such as in heat exchangers or cooling systems. Porous materials can provide trapping sites or adhesion points for the nanoparticles, enhancing their dispersion and stability within the hybrid nanofluids. The porosity of the flow medium can therefore influence the purification and filtration efficiency of the hybrid nanofluids, ensuring their cleanliness and functionality. Understanding and controlling the porosity can help optimize the flow characteristics of the nanofluids in various applications. Overall this field will focus on refining hybrid nanofluid compositions, improving modeling techniques, validating experimental findings, optimizing system designs, and exploring new applications.

Role of nanolayer on the dynamics of tri-hybrid nanofluid subject to gyrotactic microorganisms and nanoparticles morphology vis two porous disks

This paper investigates the simultaneous heat and mass transfer phenomena in nanolayers induced by morphology, motile microorganisms, and magnetohydrodynamics (MHD). The study also discusses the crucial role of viscous dissipation resulting from joule heating effects in the flow of ternary hybrid nanofluids, considering both model thermal conductivity and nanolayer thermal conductivity. The influence of various types of nanoparticles on thermal conductivity (TC) and nanolayer thermal conductivity (NTC) is examined, with a focus on the significance of chemical reactions and concentration equations. To solve the nonlinear system of ordinary differential equations, a stable and accurate numerical method is employed. The study provides valuable engineering insights, summarizing key parameters such as skin friction coefficient, Nusselt number, Sherwood number, and motile number. Several nondimensional parameter effects like Re, Pr, β, Pe,α,h,r,γ, and Sc are shown in graphical and tabulation form for both porous disks. The addition of nanolayer thermal conductivity of ternary nanoparticles at a level of 5% enhances the heat transfer rate. When the values of the radius of nanoparticles and nanolayer thickness increase, the flow of tri-hybrid nanofluid's nanolayer thermal conductivity behaves oppositely.

Numerical analysis of interfacial nanolayer thickness on Darcy-Forchheimer Casson hybrid nanofluid flow over a moving needle with Cattaneo-Christov dual flux

The interfacial nanolayer is a tinny coating of liquid molecules convened around the immersed solid nanoparticles in the base liquid which plays a vital role to control the flow and improve the thermophysical properties of the fluid. Features are more prominent for hybrid nanomaterials. Hence, the present analysis deals with the concomitant effects of an interfacial nanolayer of nanomaterials MWCNT and Ag during a viscous Darcy Forchheimer flow over a moving needle. Thermal radiation, Joule heating, and viscous dissipations concerning the Cattaneo-Christov thermosolutal flux have been introduced. An appropriate transition is applied to rationalize the substantially paired and nonlinear governing equations. Equations after similarity transformation are processed by the finite element method. The impression of different governing parameters on the governing systems in conjunction with entropy and Bejan number is displayed through graphs and tables. Graphs are drawn with an evaluation of general and hybrid nanofluids and different nanolayer thicknesses of nanoparticles. A similarity feature concerns existing literature with good promise. The thermal impact is more significant with the occurrence of Cattaneo-Christov heat flux and is further supported by thermal radiation and the Brinkman number. It has been found that Brinkman numbers boost the rate of heat transfer. Entropy generation is nonlinearly raised with advanced outcomes of radiation parameters, Brinkman number, and Reynolds number, while Bejan number shows the opposite behavior with respect to those parameters. The nanolayer thickness of the nanoparticles restricted the irreversibility phenomena of the system, and the same feature is supported by the Bejan number.