Conductivity Of Fluid Research Articles

Influence of Local Aperture Heterogeneity on Invading Fluid Connectivity During Rough Fracture Drainage

Determining the (in)efficiency of wetting phase displacement by an invading non-wetting phase (drainage) in a single fracture is key to modelling upscaled properties such as relative permeability and capillary pressure. These constitutive relationships are fundamental to quantifying the contribution, or lack thereof, of conductive fracture systems to long-term leakage rates. Single-fracture-scale modelling and experimental studies have investigated this process, however, a lack of visualization of drainage in a truly representative sample at sufficient spatial and temporal resolution limits their predictive insights. Here, we used fast synchrotron X-ray tomography to image drainage in a natural geological fracture by capturing consecutive 2.75 μm voxel images with a 1 s scan time. Drainage was conducted under capillary-dominated conditions, where percolation-type patterns are expected. We observe this continuously connected invasion (capillary fingering) only to be valid in local regions with relative roughness, λb ≤ 0.56. Fractal dimension analysis of these invasion patterns strongly aligns with capillary fingering patterns previously reported in low λb fractures and porous media. Connected invasion is prevented from being the dominant invasion mechanism globally due to high aperture heterogeneity, where we observe disconnected invasion (snap-off, fragmented clusters) to be pervasive in local regions where λb ≥ 0.67. Our results indicate that relative roughness has significant control on flow as it influences fluid conductivity and thus provides an important metric to predict invasion dynamics during slow drainage.

Nonlocal conductivity, continued fractions, and current vortices in electron fluids

Nonlocal conductivity, continued fractions, and current vortices in electron fluids

Numerical study of MHD flow over stretching cylinder with variable Prandtl number and viscous dissipation in ternary hybrid nanofluids with velocity and thermal slip conditions

Industrial applications in domains such as warm rolling, crystal development, thermal extrusion and optical fiber illustration are seeing a significant increase. These applications specifically focus on addressing the challenge of a cylinder in motion inside a fluid environment. Elevated temperatures may affect the viscosity and thermal conductivity of fluids. Understanding the relationship between temperature and the properties of fluids is crucial. In light of these presumptions, the primary goal of this study is to examine, under transverse magnetic field, shape factor, velocity, thermal slip conditions and viscous dissipation, how temperature-dependent fluid properties could enhance the heat transfer efficiency and performance evolution of ternary hybrid nanofluid. In order to study flow fluctuations, the impact of nanoparticle addition and improvements in heat transfer, a variable Prandtl number is also included. The use of similarity variables converts the controlling flow model from partial differential equations (PDEs) to ordinary differential equations (ODEs). Mathematica’s shooting strategy solves ODEs using the fourth-order Runge–Kutta (RK-IV) method. Numerical calculations were done after setting parameters to acquire the desired results. Analytical data are provided in tables and graphs for convenient usage. The results showed that the velocity profile increases as the values of [Formula: see text], Pr, M, Re and S grow, and decreases when the values of [Formula: see text] decrease. Re, Pr and S lower the temperature profile, whereas [Formula: see text], [Formula: see text] and Ec raise it. The skin friction profile steepens as [Formula: see text], S, Re and M increase relative to the stretched cylinder, and flattens as [Formula: see text] and [Formula: see text] decrease. The Nusselt number profile rises as [Formula: see text], Pr, S and Re decrease with [Formula: see text], Ec and [Formula: see text]. When the Prandtl number goes from 3.0 to 6.2 in a ternary hybrid nanofluid with brick-shaped nanoparticles, the Nusselt number goes up by around 55.7%.

Enhanced thermal conductivity of fluids by percolating high-concentration few-layer graphene

High-performance and small-sized heat exchangers have been demanded due to the miniaturization and higher output of electronic devices, lasers, and energy harvesting/storage systems. Graphene nanosheet suspension has attracted attention as a next-generation nanofluid because of its high thermal conductivity and low pressure drop, while being dispersed stably without any additives. Graphene-based nanofluids have been mostly investigated using graphene oxide, and there are a few studies on pure graphene because of the limitation in mass production and stabilization at high concentrations of graphene. In this study, we prepared a 10 wt. % high-concentration few-layer graphene suspension by pulverizing graphite particles. Scanning electron microscopy, atomic force microscopy, and Raman spectra confirmed the few-layer graphene is formed in the suspension. The thermal conductivity of the suspension increased with concentration and suddenly jumped at a specific concentration. Furthermore, a significant improvement in thermal conductivity of >40% compared to base liquid was confirmed at 10 wt. % graphene content. A similar trend was observed for electrical resistance; 10 wt. % graphene suspension showed 62% lower resistance than that of 1 wt. %. These results suggest the percolation of graphene in a liquid, which has not been observed for graphene-based materials in previous research.

A Review of Ionic Liquids and Their Composites with Nanoparticles for Electrochemical Applications

The current study focuses on reviewing the actual progress of the use of ionic liquids and derivatives in several electrochemical application. Ionic liquids can be prepared at room temperature conditions and by including a solution that can be a salt in water, or a base or acid, and are composed of organic cations and many charge-delocalized organic or inorganic anions. The electrochemical properties, including the ionic and electronic conductivities of these innovative fluids and hybrids, are addressed in depth, together with their key influencing parameters including type, fraction, functionalization of the nanoparticles, and operating temperature, as well as the incorporation of surfactants or additives. Also, the present review assesses the recent applications of ionic liquids and corresponding hybrids with the addition of nanoparticles in diverse electrochemical equipment and processes, together with a critical evaluation of the related feasibility concerns in different applications. Those ranging from the metal-ion batteries, in which ionic liquids possess a prominent role as electrolytes and reference electrodes passing through the dye of sensitized solar cells and fuel cells, to finishing processes like the ones related with low-grade heat harvesting and supercapacitors. Moreover, the overview of the scientific articles on the theme resulted in the comparatively brief examination of the benefits closely linked with the use of ionic fluids and corresponding hybrids, such as improved ionic conductivity, thermal and electrochemical stabilities, and tunability, in comparison with the traditional solvents, electrolytes, and electrodes. Finally, this work analyzes the fundamental limitations of such novel fluids such as their corrosivity potential, elevated dynamic viscosity, and leakage risk, and highlights the essential prospects for the research and exploration of ionic liquids and derivatives in various electrochemical devices and procedures.

Growth mechanism of high‐voltage electric pulse rock breaking 3D plasma channel in drilling fluid environment

AbstractHigh‐voltage electric pulse rock breaking has excellent potential for exploiting deep geothermal resources. Numerous researchers have conducted experimental studies on this topic, particularly in rock mechanics, where the breakdown occurs. However, there has been limited scholarly research on drilling fluid. Therefore, the study focuses on the drilling fluid suitable for electric pulse drilling, considering the characteristics of electric pulse rock breaking, which differ from traditional rock breaking. The study focused on the impact of various drilling fluid parameters on the effectiveness of electric impulse rock breaking using red sandstone as the experimental material. This was investigated using the finite element method, and indoor electric rock‐breaking tests were conducted in a drilling fluid environment. The results indicate that the plasma channel mainly grows in the permeable layer of the drilling fluid, resulting in shallow rock breaking depth in the drilling fluid environment. The pore permeated by drilling fluid guides the growth of the plasma channel. The higher the conductivity of the drilling fluid, the closer the ion channel of rock breaking by electric pulse is to the rock surface. This results in a smaller crushing volume and shallower damage depth, which is more detrimental to rock breaking by an electric pulse. The viscosity of drilling fluid can impede the breakdown to some extent. In this paper, the influence of drilling fluid parameters on electro‐pulse rock‐breaking technology is preliminarily studied, which has significant reference value for the selection of actual drilling fluid.

Investigating the magnetohydrodynamics non-Newtonian fluid movement on a tensile plate affected by variable thickness with dufour and soret effects: Akbari Ganji and finite element methods

Significant progress in the investigation of non-Newtonian Williamson and Casson boundary layer flow has led us to explore the extension of non-Newtonian Williamson and Casson hydromagnetic boundary layer flow in an electrically conductive fluid subjected to a strong magnetic field and a uniform thermal field. This study is divided into two interconnected parts. The first part converts the nonlinear system governing the Partial Differential Equations into a simpler, nonlinear, ordinary differential equation. It is then analyzed using the Akbari Ganji method (AGM). The output data from the first part, solved using AGM, is compared and evaluated with the output data from the second part, solved with the assistance of finite element (FEM) methods. This research validates previous works with current methodologies. Subsequently, changes in temperature and concentration parameters, influenced by variations in magnetic parameters, are obtained and analyzed through three-dimensional charts. Upon reviewing the results, it is observed that the distribution of concentration and temperature is dependent on the distribution of the magnetic parameter, with an increase in concentration and temperature being influenced by the rise in the magnetic parameter. Other parameters are also examined, each of which is elaborated upon below. The effects of Bi1, Sr, and Sc parameters on temperature are investigated, and design points for achieving optimal and effective design are presented in the graph. Some applications of magnetohydrodynamics and non-Newtonian fluids include improving fluid pumping technologies. Using magnetohydrodynamics in non-Newtonian fluid pumping systems can help improve efficiency and reduce energy costs. Additionally, enhancing the efficiency of heat transfer systems using magnetohydrodynamics can help improve efficiency and reduce energy losses in these systems.

Numerical study of liquid metal magnetoconvection and heat transfer in an electrically conductive square duct

Mixed convection of an electrically conductive fluid in a square duct with imposed transverse magnetic field is studied using Large Eddy Simulation (LES) paradigms. The duct walls are electrically conductive, with the wall conductivity parameter cw ranging from 0 to 0.5. The Reynolds number is Re=5602 and the Prandtl number is Pr=0.0238. The focus of the study is on flows at Hartmann numbers Ha⩽125, Richardson numbers Ri⩽10 and two different thermal boundary conditions are considered: four wall uniform heat fluxes and one-sided heating (fixed wall temperature). The results show that the transition from laminar to turbulent flow depends not only on the ratio Ri/Ha, but also on cw and on the local thermal boundary conditions. In the turbulent regime with one-sided heating, the turbulent heat fluxes play an important role in the total heat transfer, in contrast with the typical behaviours of liquid metals. Moreover, the turbulent and thermal structures are highly dependent on the thermal boundary conditions, which completely alter the flow structure. It is also found that at cw≥0.01 the turbulent heat fluxes decrease.

Dynamic behavior of electro-osmosis in variable charge soils: Insights on termination and direction reversal

Electro-osmosis offers an effective method for dewatering and remediating low permeability soil. Long-term observations on nonlinear behavior of electro-osmosis and the influencing factors are not commonly reported. Connection between cessation and direction reversal of electro-osmotic flow (EOF), and the evolution of electro-chemical parameters inside of the soil mass thus remains unclear. The dynamic response of EOF in variable charge soil could be significant, whereas the investigations on which are currently lacking. A series of electro-osmotic experiments were performed with two natural variable charge soils. The results indicated that initial electro-osmotic rate was positively proportional to electric current and initial electrical conductivity of the pore fluid, which could be explained by the ion migration model. The dynamic evolution of electro-osmotic rate and electro-chemical parameters corresponding to the solute and pH conditionings at the electrode compartments demonstrated that: 1) coupling effects of non-uniform distribution of voltage gradient and pH determined the magnitude and direction of EOF rate; 2) compared to the final pHIEP value, the bigger, close and smaller values of the novel index “voltage gradient weighed mean of spatial pH″ represented the forward, terminated and reversed EOF respectively; 3) the classical Helmholtz-Smoluchowski model are proved to be more applicable interpreting the coupled nonlinearity of electro-osmosis during the later steady phase. This work would facilitate future research for a comprehensive electro-osmotic model, and provide guidance to condition the initial and boundary conditions in application of electro-osmotic dewatering and electrokinetic remediation.

Computational study of effect of hybrid nanoparticles on hemodynamics and thermal transfer in ruptured arteries with pathological dilation

The intended research aims to explore the convection phenomena of a hybrid nanofluid composed of gold and silver nanoparticles. This research is novel and significant because there is a lack of existing studies on the flow behavior of hybrid nanoparticles with important physical properties of blood base fluids, especially in the case of sidewall ruptured dilated arteries. The implementation of combined nanoparticles rather than unadulterated nanoparticles is one of the most crucial elements in boosting the thermal conduction of fluids. The research methodology encompasses the utilization of advanced bio-fluid dynamics software for simulating the flow of the nanofluid. The physical context elucidates the governing equations of momentum, mass, momentum, and energy in terms of partial differential equations. The results are displayed in both tabular and graphical forms to demonstrate the numerical and graphical solutions. The effect of physical parameters on velocity distribution is illustrated through graphs. Furthermore, the study’s findings are unique and original, and these computational discoveries have not been published by any researcher before. The finding implies that utilizing hybrid nanoparticles as drug carriers holds great promise in mitigating the effects of blood flow, potentially enhancing drug delivery, and minimizing its impact on the body.

An Electrical Parameter Characterizing Solute Heterogeneity: The Mixing Factor M

AbstractQuantitative estimates of hydrological state variables using electrical or electromagnetic geophysical methods are systematically biased by overlooked heterogeneity below the spatial scale resolved by the method. We generalize the high‐salinity asymptotic limit of electrical conduction in porous media at the continuous (e.g., Darcy) scale, by introducing a new petrophysical parameter, the mixing factor M, which accounts for the effect of fluid conductivity heterogeneity on the equivalent electrical conductivity tensor; it is expressed in terms of the volume‐average of the product of mean‐removed fluid conductivity and electric fields. We investigate the behavior of M for static and evolving fluid conductivity scenarios. Considering 2‐D ergodic log‐normal random fields of fluid conductivity, we demonstrate, in absence of surface conductivity, that observing the components of the M‐tensor allows univocally determining the variance and anisotropy of the field. Further, time‐series of the M‐tensor under diffusion‐limited mixing allows distinguishing between different characteristic temporal scales of diffusion, which are directly related to the initial integral scales of the salinity field. Under advective‐diffusive transport and for a pulse injection, the time‐series of M have a strong dependence on the Péclet number. Since M is defined in the absence of surface conductivity, we investigate how to correct measurements for surface conductivity effects. The parameter M provides conceptual understanding about the impact of saline heterogeneity on electrical measurements. Further work will investigate how it can be incorporated into hydrogeophysical inverse formulations and interpretative frameworks.

Preparation and application method of CNTs dispersion solution for direct electroplating on circuit board holes

Abstract The utilization of carbon black dispersion solutions for the black hole method is common in the electronics industry due to their cost-effectiveness and stable performance. However, the slow electroplating speed caused by carbon black’s poor conductivity can impact industrial processes and time. This paper introduces a water-based dispersion solution of carbon nanotubes (CNTs) for the direct copper electroplating process on circuit board holes and its application method. The dispersion solution comprises “shortened” CNTs with a small aspect ratio, a dispersant, a pH adjuster, and other optimization agents. This black hole liquid functions as a conductive fluid with “shortened” CNTs as the conductive medium, exhibiting high dispersibility, strong through-hole capability, low resistance, and excellent adhesion. Its performance surpasses that of black hole liquids using single-carbon black as the conductive medium. The key advantage lies in avoiding the entanglement associated with conventional long aspect ratio CNTs, thereby enhancing the conductivity of the water-based dispersion solution. This facilitates the formation of a uniform conductive film through the electrostatic self-adsorption method, which is suitable for preparing a conductive film on circuit board hole walls before copper electroplating.

Revised Enskog theory and molecular dynamics simulations of the viscosities and thermal conductivity of the hard-sphere fluid and crystal.

Hard-sphere (HS) shear, longitudinal, cross, and bulk viscosities and the thermal conductivity are obtained by molecular dynamics (MD) simulations, covering the entire density range from the dilute fluid to the solid crystal near close-packing. The transport coefficient data for the HS crystal are largely new and display, unlike for the fluid, a surprisingly simple behavior in that they can be represented well by a simple function of the density compressibility factor. In contrast to the other four transport coefficients (which diverge), the bulk viscosity in the solid is quite small and decreases rapidly with increasing density, tending to zero in the close-packed limit. The so-called cross viscosity exhibits a different behavior to the other viscosities, in being negative over the entire solid range, and changes sign from negative to positive on increasing the density in the fluid phase. The extent to which the viscosity tensor and thermal conductivity of the HS crystal can be represented by revised Enskog theory (RET) is investigated. The RET expressions are sums of an instantaneous (I), a kinetic (K), and a so-called α part. The I part of the transport coefficients evaluated directly by MD are statistically indistinguishable from those of the corresponding kinetic theory (Enskog and RET) expressions. For the K part the integral over the spatial two-particle distribution function at contact was determined and the α part was estimated using the direct correlation function and density functional theory approximations. All three parts were determined in this work which allowed the accuracy of RET for solid systems to be assessed rigorously. It is found that in the case of the thermal conductivity the predictions of RET are in excellent agreement with the MD results. Also, for the shear viscosity the agreement over the entire solid phase is quite good but is considerably worse for the three remaining viscosities in the solid phase.

Effect of geothermal heat transfer on performance of the adiabatic compressed air energy storage systems with the salt cavern gas storage

The temperature and pressure of compressed air influence the output performance of the adiabatic compressed air energy storage system with salt cavern gas storage. However, current studies often overlook the impact of geothermal heat transfer on system performance. In this paper, a mathematical model of the energy storage system with salt cavern gas storage is developed, considering the geothermal heat transfer in wellbore and salt carven. The model is used to illustrate the effects of geothermal heat transfer on the system performance through a sensitivity analysis of some key parameters. The results show that geothermal heat transfer will significantly reduce the gas and energy storage capacity, with a maximum reduction of 15.3 % and 11.1 % at a depth of 2000 m, respectively. Furthermore, this reduction would increase with the depth of the salt cavern. The geothermal energy reduces the round-trip efficiency from 68.7 % to 66.26 % and the energy storage density from 5.18 kWh·m−3 to 4.32 kWh·m−3. For common salt cavern gas storage at a depth of about 600 m ∼ 1200 m, the negative impacts of geothermal heat transfer on round-trip efficiency and energy storage density are less than 2.2 % and 0.5 kWh·m−3, respectively. Sensitivity analysis also demonstrates that the primary factors influencing the system’s performance are the thermal conductivity of the surrounding rock, the volume of the salt cavern, and the length of the wellbores. The secondary factors include the heat transfer coefficient on the inner wall of the salt cavern, the inner pipe radius, and the roughness of the inner pipe. Irrelevant factors include the thermal conductivity of the protective fluid and the thermal conductivity of the cement layer. The proposed comprehensive mathematical model of the system and simulation findings aid in forecasting the performance of storage systems and offer theoretical guidance for the design of large-scale compressed air energy storage systems.

Numerical analysis of the MHD Williamson nanofluid flow over a nonlinear stretching sheet through a Darcy porous medium: Modeling and simulation

Abstract In the current study, we delve into examining the movement of a nanofluid within a Williamson boundary layer, focusing on the analysis of heat and mass transfer (HMT) processes. This particular flow occurs over a sheet that undergoes nonlinear stretching. A significant facet of this investigation involves the incorporation of both the magnetic field and the influence of viscous dissipation within the model. The sheet is situated within a porous medium, and this medium conforms to the Darcy model. Since more precise outcomes are still required, the model assumes that both fluid conductivity and viscosity change with temperature. In this research, we encounter a system of extremely nonlinear ordinary differential equations that are treated through a numerical technique, specifically by employing the spectral collocation method. Graphical representations are used to illustrate how the relevant parameters impact the nanoparticle volume fraction, velocity, and temperature profiles. The study involves the computation and analysis of the effect of physical parameters on the local Sherwood number, skin friction coefficient, and local Nusselt number. Specific significant findings emerging from the present study highlight that the rate of mass transfer is particularly influenced by the thermophoresis factor, porous parameter, and Williamson parameter, showing heightened effects, while conversely, the Brownian motion parameter demonstrates an opposing pattern. The results were computed and subjected to a comparison with earlier research, indicating a notable degree of conformity and accord.

Modified 3ω conductivity technique for measurements of thermal conductivity in cryogenic fluids

An instrument based on a modification to the 3-omega thermal conductivity technique that allows precise measurement of thermal properties in fluids is presented. Existing hot-wire techniques have difficulty measuring thermal conductivity because of the effects of natural convection distorting the measurement, however the standard 3-omega technique has been used extensively in the measurement of the properties of solids with great success. To address the challenge posed by natural convection in fluids, we modify the boundary condition of the 3-omega device configuration to be finite in extent, thereby restricting fluid motion and enabling a direct high-precision measurement of a fluid’s thermal conductivity. This modified scenario also presents an opportunity for a simultaneous measurement of the thermal diffusivity of the fluid. The behavior of the device is described with the reformed boundary conditions to show how a simultaneous measurement is made. By applying a constant temperature finite boundary condition, the solution characteristic in the frequency domain gains features that allow for simultaneous measurements of the fluid thermal conductivity and diffusivity. Given the density of the fluid, measured separately, the specific heat of the fluid can be calculated. The effects of the thermal properties of the measurement wire influence the measurement characteristic, and only when the wire thermal properties are sufficiently small compared to those of the fluid can a simultaneous measurement be made. Due to limitations in the dynamic reserve of the measurement devices, a setup is described that allows the signal of interest to be extracted and a precise measurement to be made with minimal distortion. Initial data on the thermal conductivity of helium is presented in the 4-300K temperature range. Preliminary specific heat data is also presented. Limitations on the device’s thermal properties prevent a specific heat measurement above 70K. This data is compared with reference fluid properties databases to validate the device performance.

Squeezing MHD Flow of Sodium Alginate-Based Casson Hybrid Nanofluid with Soret and Dufour Effects

Ultrahigh-performance cooling is one of the essential requirements in the industrial technology. Hence, the new heat transfer fluid, hybrid nanofluid is introduced to increase the thermal conductivity of fluid and investigated with various physical parameters. The unsteady magnetohydrodynamics (MHD) flow of Casson hybrid nanofluid through two surfaces in a permeable medium with chemical reaction are explored. The hybrid nanoparticles of Alumina and Copper is dispersed in the base fluid of sodium alginate . The discretize equations are solved using similarity transformation and Keller-box methods. The comparison of the current results with the published results for validation is conducted and discovered in proper agreement. The impacts of squeeze, magnetic, porous media, chemical reaction, heat sink/source, and Soret and Dufour on behaviour and physical quantities of flow are discussed. The graphical results show the squeeze of two surfaces accelerates the fluid velocity near the upper plate region. Further, the velocity slowing down when and increases, and it elevates as and rises in the middle of channel. The increment of heat transfer rate and temperature of fluid is shown for increasing Ec, y and Du, and the opposite behaviour is discovered with raise in. The fluid concentration decreases and the mass transfer rate enhances for rising Sr. The concentration enhance and rate of mass transfer reduce with the constructive chemical reaction, whereas contrary effects is shown for destructive chemical reaction.

Why Carbon Nanotubes Improve Aqueous Nanofluid Thermal Conductivity: A Qualitative Model Critical Review

Media thermal conductivity is important in various heat-transfer processes. Many conventional fluid conductors suffered low conductivity and environmental issues. Therefore, research was active in finding out alternative systems, mostly relying on aqueous liquids that are low-cost and ecofriendly. After the emergence of carbon nanotubes (CNTs), with their many special structural, electrical and thermal properties, they have been examined for many applications, including heat-transfer processes. Adding CNTs to water yields CNT aqueous nanofluids that have been widely investigated as heat-transfer media. The literature shows that CNT addition improves water thermal conductivity and other water properties, such as viscosity, surface tension, freezing point and boiling point. The literature also shows that nanofluid thermal conductivity improvement is affected by CNT type and concentration, in addition to other factors such as surfactant addition. All these subjects were widely described in literature, focusing on experimental, modelling and theoretical accounts. Despite the wide literature, there exist inconsistencies and discrepancies between reports that need to be justified. In addition to technical papers, many reviews were published on various aspects of the subject including experimental results and mathematical modeling. However, the very basic question here is as follows: Why does adding CNT to water affect its thermal conductivity? In spite of the wide published literature, this issue was not targeted in a simple qualitative approach. This review provides a clear understanding of how CNTs improve thermal conductivity of aqueous nanofluids. A qualitative model is presented to explain mechanisms behind improvement as presented in the literature. CNT type effects are discussed with other factors such as aspect ratio, Reynold number, dispersion quality, composition, temperature and additives. CNT functionalization is described. Relations to estimate nanofluid thermal conductivity are discussed. The model will help specialists to tailor CNT aqueous nanofluid characteristics as desired by varying types and concentrations of CNT and surfactant, and other factors.

Darcy Forchhiemer imposed exponential heat source-sink and activation energy with the effects of bioconvection over radially stretching disc

The Darcy–Forchheimer model is a commonly used and accurate method for simulating flow in porous media, proving beneficial for fluid separation, heat exchange, subsurface fluid transfer, filtration, and purification. The current study aims to describe heat and mass transfer in ternary nanofluid flow on a radially stretched sheet with activation energy. The velocity equation includes Darcy–Fochheimer porous media effects. The novelty of this study is enhanced by incorporating gyrotactic microorganisms which are versatile and in nanofluid can greatly improve the thermal conductivity and heat transfer properties of the base fluid, resulting in more efficient heat transfer systems. Furthermore, the governing PDEs are reduced to ODEs via appropriate similarity transformations. The influence of numerous parameters is expanded and physically depicted through the graphical illustration. As the Forchheimer number escalates, so do the medium's porosity and drag coefficient, resulting in more resistive forces and, as a result, lowering fluid velocity. It has been discovered that increasing the exponential heat source/sink causes convective flows that are deficient to transport heat away efficiently, resulting in a slower heat transfer rate. The concentration profile accumulates when the activation energy is large, resulting in a drop in the mass transfer rate. It is observed that the density of motile microorganisms increases with a rise in the Peclet number. Further, the results of the major engineering coefficients Skin-friction, Nusselt number, Sherwood number, and Microorganism density number are numerically examined and tabulated. Also, the numerical outcomes were found to be identical to the previous study.

Exploration of thermal radiation and stagnation point in MHD micropolar nanofluid flow over a stretching sheet with Navier slip

The quest to strengthen heat conduction of thermal science base fluid for effective industrial outputs and engineering derives has recently increased. Thus, this study aims to determine how thermal radiation and slip effects affect the flow of a micropolar nanofluid near a stagnation point over an extending sheet. Using similarity transformations, the flow-controlling partial differential equations (PDEs) are turned into a set of non-linear ordinary differential equations (ODEs). The non-linear system of equations has been solved by the numerical technique Runge-Kutta-Fehlberg integration scheme implementing the shooting technique with suitable conditions to generate a numerical solution. The essential factors affecting the flow are depicted graphically and tabularly. Additionally, a comparison is conducted between the present result and previously published data on the Nusselt and Sherwood numbers; it claims that thermophoresis and Brownian motion vary under some restrictive conditions. An increase in the magnetic field parameter was found to boost the velocity of the micropolar nanofluid. In contrast, a rise in the micropolar parameter reduces the angular velocity.