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This study investigates analytically the influence of nanoparticle shapes on an unsteady mixed convective viscoelastic MHD nanofluid flow in a horizontal channel with oscillating walls in a saturated porous medium. The effect of radiation is also considered in the energy equation. The considered NPs are Cu, Ag, Al2O3, TiO2, and Fe3O4, with base fluids H2O and C2H6O2. The considered different shapes of NPs are cylinder, platelet, blade, and brick. The study examines three flow situations based on physical boundary conditions. The perturbation method is employed to solve the flow governing equations for three different flow situations based on physical boundary conditions: Case (i) flow in a horizontal channel with both lower and upper walls stationary; Case (ii) the upper wall of the channel is in oscillation while the lower one is constant; Case (iii) both walls of the channel are in oscillatory motion. The velocity and temperature distributions, as well as the skin friction coefficient and heat transfer rate, are analyzed through graphs and tables to assess the impact of various governing parameters. From the results, it is found that brick-shaped NPs exhibit more strength to the velocity and temperature distributions, followed by cylinder, platelet, and blade for both water-based and EG-based NF. [ABSTRACT FROM AUTHOR]

This paper presents an investigation of magnetohydrodynamics (MHD) Casson nanofluid flow along a stretchable surface through a permeable medium. The modeling of the physical phenomena is considered with impact of thermal radiation, heat generation, slip conditions and suction. Transformations of the governing set of mathematical equations for the physical model are carried out into nonlinear ordinary differential equations (ODEs) with appropriate similarity variables. The nonlinear ODE solutions are carried out using the optimal homotopy analysis technique (OHAM), and the findings are presented for determining the influences of the emerging important parameters. The results indicate that velocity field increases in respect of porosity parameter, Casson fluid parameter and magnetic parameter while it declines for enhancing velocity slip and suction parameters. The temperature profile shows rising behavior for heat source, Prandtl number, thermophoresis, radiation and Brownian motion parameters while it declines for enhancing thermal slip parameter. Moreover, the concentration profile enhances for rise in Brownian motion parameter while it reduces for Schmidt number and nanoparticle parameter. We also showed the accuracy of the present results by indicating that skin friction values for varied magnetic parameters agree with earlier findings in the literature. [ABSTRACT FROM AUTHOR]

This study examines the flow dynamics and heat transfer characteristics of Maxwell fluid in a channel influenced by magnetohydrodynamics (MHD), Joule heating, thermal radiation, and boundary layer suction/blowing effects. The governing partial differential equations (PDEs) for momentum, energy, and concentration are transformed into ordinary differential equations (ODEs) using similarity transformations. The boundary value problem (BVP) is solved numerically using the bvp4c solver in MATLAB, yielding accurate solutions for velocity, temperature, and concentration profiles under various parameters. Key findings reveal that the porous parameter decreases the velocity profile but increases the temperature profile for both suction and blowing effects. Additionally, the MHD, Deborah, and Eckert numbers significantly influence the velocity and temperature profiles differently under these conditions. This study highlights the crucial role of integrating MHD, thermal, and boundary control effects to optimize performance and efficiency in engineering systems involving Maxwell fluids, with applications in polymer processing, biomedical engineering, electronics cooling, oil recovery, and chemical processing. [ABSTRACT FROM AUTHOR]

The current study investigates the three-dimensional radiative and convective Casson hybrid nanofluid flow and heat transfer with the Cattaneo–Christov heat flux model over an inclined spinning and extending disk subjected to an applied magnetic field. Additionally, the study considers the impacts of Joule’s heating and viscous dissipation. Mathematical modelling of the nanofluid flow problem containing Ag and multiwalled carbon nanotubes (MWCNT) nanoparticles with water as the base fluid in a Darcy medium is done using a cylindrical coordinate system. The simplified system of equations is subjected to the spectral quasilinearisation method (SQLM) approach for the graphical and tabular representations. Examining key parameters, such as magnetic field, Bejan number, angle of inclination, disk movement parameter and disk rotation reveals interesting results on velocity and temperature profiles. The research concludes that the Bejan number increases with higher values of temperature ratio, radiation and magnetic parameters, while it decreases with increasing Casson parameter and Brinkman number. Radial wall friction decreases with improved magnetic field, temperature ratio, stretching and porosity parameters, but tangential wall friction increases. The present results are compared with the one already existing in literature to validate the numerical scheme and the results are found to agree well with the previously published work. The application of hybrid nanofluid flow over rotating and stretching disks is widespread in various fields, including rotating machinery, electronic devices, patient treatment instruments, crystal growth method, etc. [ABSTRACT FROM AUTHOR]

In this paper, an analytical approach combined with a two-dimensional computational fluid dynamics (CFD) model is pursued to simulate the fluid flow in a monopropellant thruster for satellite propulsion systems. The thruster utilizes hydrogen peroxide (H2O2) as a green propellant at a concentration of 87.5%, with a catalytic bed based on spherical silver particles. Through a parametric analysis of particle diameter, we aim to optimize the design of a monopropellant thruster capable of generating a thrust of 20N. For this purpose, a program in CFD code in the commercially available ANSYS Fluent software is used to solve the energy, momentum, mass transfer, and species transport equations governing the thruster system. The local thermal non-equilibrium (LTNE) approach is used to describe the heat transfer occurring through both the solid and fluid phases within the catalyst bed. The results demonstrate that particle size significantly affects the thermal behaviour, species mass fraction, and exit velocity. An optimum diameter of 0.65mm exhibits the optimal performance of the monopropellant thruster, ensuring efficient decomposition of H2O2 at 968K and providing the required level of thrust force with a specific impulse of about 120s. [ABSTRACT FROM AUTHOR]

The object of this research is to examine the combined effects of mass and thermal Biot numbers on the properties of a Powell-Erying fluid flow that is two-dimensional, constant, viscous, incompressible, and non-Newtonian. In the direction of the flow is an extending sheet encircled by a porous medium. Further consideration is given to the existence of a chemical reaction, thermophoresis, Brownian motion, and velocity lapse, among other factors. Utilizing the Powell-Erying Cauchy non-Newtonian model, the viscoelastic effect is accounted for. When establishing concentration and temperature boundary conditions, thermal and mass Biot numbers are incorporated. By utilizing graphs, one can examine the impacts of a variety of engineering parameters on concentration profiles, velocity, and temperature. This is accomplished through the implementation of numerical solutions derived via the Runge–Kutta method. By utilizing graphs, one can examine the impacts of a variety of engineering parameters on concentration profiles, velocity, and temperature. This is accomplished through the implementation of numerical solutions derived via the Runge–Kutta method. Furthermore, the Nusselt number, Skin-friction, and Sherwood number coefficients are evaluated and shown in a tabular format utilizing the same parameters. In the end, the numerical outcomes obtained from this investigation are substantiated and considered to be highly consistent with the findings that were previously documented. [ABSTRACT FROM AUTHOR]

The idea of a hybrid nanofluid (HNF) has sparked curiosity among many scientists because of its ability to enhance thermal characteristics, leading to elevated rates of heat transfer (HT). These HNFs are utilized in various engineering and industrial settings, such as electronics cooling, manufacturing, naval structures, biomedical applications, and drug delivery. The current study investigates the analysis of irreversibility in EMHD [Cu + TiO2/H2O]h flow over a stretching sheet with radiation and viscous dissipation. The governing PDEs are converted into ODEs using similarity variables. These ODEs are then solved using the RKF method along with a shooting technique. The effects of different physical parameters on the velocity and temperature distributions of the HNF, as well as on HT and surface drag force, are thoroughly examined and presented in graphs. The velocity of [TiO2/water]n flow declines as the magnetic field strength rises, but it rises with greater electric field values for [Cu + TiO2/water]h. The temperature of the [Cu + TiO2/water]h increases with elevated levels of radiation, Eckert number, and heat generation strength. Higher Reynolds and Brinkman numbers result in a rise in entropy generation for [Cu + TiO2/H2O]h, whereas the Bejan number decreases to the same extent. The HT rate in [Cu + TiO2/H2O]h increases by 3.05% as the Eckert number rises, while it drops by 4.01% when there is significant thermal radiation. Skin friction reduces by 3.21% in [TiO2/water]n as the electric field strength increases, whereas it decreases by 4.05% with an increase in magnetic field strength. These discoveries offer valuable perspectives on furthering the utilization of HNFs in engineering and industrial operations. [ABSTRACT FROM AUTHOR]

Over the last few decades, many kinds of advanced substances that are acceptable for specific aerospace applications have been developed. An aircraft engine has a number of duties that are performed by kerosene oil. These responsibilities include oiling, air conditioning, servicing, preventing corrosion and reducing loudness. Maintenance is a matter of extreme importance. Without maintenance, it is only inevitable that any moving component might have the capacity to run away quickly. This project’s efforts are focused on reducing expenditures by extending the usable lifetimes of aviation components. Additionally, the initiative aims to improve fuel efficiency, load capacity and travel distance. The importance of the heat transfer investigation on MHD dusty hybrid nanofluid across a porous stretching sheet with entropy generation and thermal radiation is examined in the current research. We used the self-similarity transformation to transform the partial differential equation into ordinary differential equations. After applying transformations, for graphical purposes we have used the Bvp4c technique in MATLAB solver. The effect of active important parameters affecting the fluid’s capacity to transfer importance is shown in graphs and tables. For higher values of the magnetic field parameter, the velocity outline decreased, while the opposite nature was noticed in the energy profile. Based on our investigation, we found that mixed nanofluids are more effective in transferring energy carriers compared to dusty tiny fluids. [ABSTRACT FROM AUTHOR]

As a promising green energy technology, low-temperature proton exchange membrane (PEM) electrolysis exhibits different reaction efficiencies and flow performances under various flow channel structures, but the specific impacts of these different layouts on performance are not well understood. To reveal the influence of the channel layouts, a two-phase PEM electrolysis model is established based on the experiment in this paper. Combing with flow characteristics, current density, and product distribution in the porous transport layers (PTLs) and catalyst layers (CLs), the results indicate that the flows from different directions have a significant impact on the electrolyzer. The vertical flow, perpendicular to the CLs, can greatly alleviate the product accumulation; meanwhile the transverse flow, parallel to the CLs, has a weaker but noticeable effect in gas ventilation. Partial gas will continue to accumulate in the region of weak vertical flow, especially at the end of the transverse flow. Except for the pin-type layout, other structures have a neat and orderly transverse flow within the porous medium, in the direction perpendicular to the flow channel's orientation. This flow pattern leads to product accumulation increasing along the exit direction, as well as product stagnation in the region of weak flow intensity. To facilitate the product discharge, a new flow channel layout, the pyramidal flow layout is proposed, which navigates the flow trend and enhances the convection near the exit. This new layout greatly evens out the current density and product concentration distribution. • Based on two-phase flow PEM electrolysis model of different flow channel layouts. • Finding a universal flow pattern within the porous medium among different layouts. • Proposed a new flow layout with better product distribution and discharge efficiency. [ABSTRACT FROM AUTHOR]

This paper provides a comparative numerical analysis of unsteady hybrid nanofluid (Ag + TiO 2 /H2O) and nanofluid (TiO2/H2O) flows through a permeable linear stretching cylinder placed in a porous medium has been presented in the presence of oblique Lorentz force. The flow regulating boundary layer equations has been governed due to the sway of the suction, viscous-Ohmic dissipation, heat source, thermal radiation and first-order velocity slip with imposing convective boundary conditions on the surface. The self-similar transformation has been employed to convert the governing coupled nonlinear PDEs into a set of ODEs and finally solved them numerically by fifth-order Runge–Kutta method with shooting technique. Finally, a comparative study has been made on the thickness of the momentum and thermal boundary layers due to the effect of governing parameters for simple and hybrid nanofluids. Further, a numerical observation on local skin friction and thermal-transport coefficients is presented with the help of tables. The result indicates that the progressiveness of the velocity profile reduces for the unsteadiness parameter, Hartree pressure gradient, velocity slip parameter, inclination parameter, porous medium parameter, magnetic parameter and suction parameter while improving for velocity ratio parameter and temperature profiles increases with Biot number, Eckert number, heat generation parameter and thermal radiation parameter, but decreases for Hartree pressure gradient and velocity ratio parameter. This work has found various applications in high-temperature and cooling processes, paints, conductive coatings, medicines, space technology, biosensors, conductive coatings and so on. [ABSTRACT FROM AUTHOR]

The utilization of a ternary hybrid nanofluid, a recent development in the realm of nanofluids, can result in improved heat transfer. In the ongoing study, a ternary hybrid nanofluid flow is utilized, and it is carried out atop a porous spinning disc, which is exposed to a magnetic field, heat generation, thermal radiation, and Casson fluid. In this study, Blood/Water are taken as base fluids and (Ag–Au–Al2O3) are considered as a ternary hybrid nanoparticle. Nanoparticles made of gold and silver are put to use in a vast number of industries and fields, including nanotechnology and medicine. As a result of surface effects and quantum effects, these precious metals exhibit unique features in nanoform that play a vital role in with optical, magnetic, chemical, and mechanical behavior. Al2O3 unique optical, physical and biochemical qualities make it worthwhile for numerous uses, including nanophotonic, catalysis and the fabrication of high-energy composites. A set of relevant similarity transformations is used to generate non-dimensional forms of controlling paired nonlinear Partial Differential Equations (PDEs). MATLAB is used to perform a numerical solution with ODE45. In addition, the velocity outline decreases, and the temperature profile increases slightly before decreasing over a revolving disk when the values of magnetic parameters are increased. The distribution and radiant heat components heat up as the level gets higher. Aim and objectives of the study: The aim of this study is to analyze the Comprehensive Scrutinization of Ternary hybrid and Casson flow in a conducting porous rotating disk with internal heating. The primary objective of this analysis is to increase awareness of the impending energy crisis among those working in the industrial and technological sectors. Ternary nanoparticles (NPs) have a wide range of applications, which lends credence to the developed model. For example, Al2O3 can be used in a variety of ways that benefit society, it is used in water purification to remove water from the gas streams and extend people's lives. [ABSTRACT FROM AUTHOR]

Effects of nanoparticle and steam injection on the extraction of Iranian American Petroleum Institute (API) 14 heavy oil from a model porous medium at temperatures of 110, 150, and 200 °C were investigated. Nanoparticle content was 1 %, 3 %, and 5 %, and injection flow rates were 0.018, 0.036 and 0.072 mL h−1. In short‐term injection, increasing the injection temperature to 200 °C and the flow rate to 0.072 mL h−1 resulted in the highest recovery. In the mid‐term injection, the highest recovery factor was at a temperature of 150 °C and flow rate of 0.036 mL h−1, while the results of the long‐term injection predicted a non‐monotonic effect of flow rate. The effect of alumina content on the recovery factor is less than that of temperature and flow rate. Interestingly, alumina content also has non‐monotonic effects on the recovery factor. [ABSTRACT FROM AUTHOR]

Entropy measures the disorderness and randomness in the thermal systems. It has significant influence over efficiency and performances of the thermal systems. The motive of the research paper is to present a comparative analysis of entropy generation of a heat dissipative Darcy–Forchheimer flow of copper (Cu/H2O)-based mono and (CuAl2O3/H2O)-based hybrid nanofluid under the influence of thermal dispersion. The mathematical model of the conceptualized flow problem is formulated using single phase nanofluid model along with Darcy–Forchheimer equation for non-Darcy porous medium flow. The system of dimensional Partial Differential Equation (PDE) depicting the flow problem is converted in the system of dimensionless Ordinary Differential Equation (ODE) using the suitable similarity variables and has been solved by MATLAB’s bvp4c package. The flow variables, engineering parameters like skin friction and Nusselt number along with entropy generation, have been analyzed for the active parameters inherited in the problem. The findings suggest that heat transfer rate on the surface enhances with the increment in thermal dispersion parameter. Further, it is reported that the hybrid nanofluid generates lesser entropy as compared to the mono-nanofluid. This research has potential to serve the real-life applications based on electronics and geothermal systems. [ABSTRACT FROM AUTHOR]

The study offers a thorough evaluation of the complex fluid dynamics and heat transfer phenomena in Williamson viscoelastic fluid flow, taking into account thermal radiations and variable thermal conductivity. The paper extends its analysis to include heat transfer effects, which are critical in several engineering and industrial applications, and digs into the complexity of non-Newtonian fluid behavior, with a special focus on thermal radiation, heat production, diffusion and viscous dissipation. The study makes use of mathematical models and numerical method RK4 to clarify the nonlinear interactions between convection and diffusion processes in this viscoelastic fluid. The energy and concentration equations are simulated in the presence of the modified Fourier and Fick laws. Moreover, the predicted heat flow is based on the Cattaneo–Christov theory. This research also sheds light on the interaction between rheological properties and thermal characteristics, providing important new knowledge to the broader field of fluid dynamics and heat transfer. [ABSTRACT FROM AUTHOR]

AbstractA study of mass and heat transport on fully developed laminar and transient free convective flow in a vertical cylinder containing a porous substance inside it. The Laplace Transform Method (LTM) is used to solve the governing equations with suitable boundary conditions. A compact form solution represented by using Bessel and modified Bessel functions. The numerical results were thoroughly scrutinized using graphs and tables to illustrate the effects of newly discovered fluid characteristics, including time, Grashof, mass Grashof, Schmidt, Prandtl, Darcy numbers, viscosity ratio on the concentration and the velocity profiles. The velocity and concentration profiles progressively increase with varying time values until reaching a steady state. Furthermore, it is found that the velocity profiles are decreased by the Prandtl, Schmidt number, and viscosity ratio. In contrast, the Darcy, Grashof, and mass Grashof numbers exhibit an opposite effect. The rate of mass transport, skin friction, and mass flux are presented in tables. The major finding of the current research is that the viscosity ratio parameter decelerates the skin friction and mass flux. This study has potential applications in innovative fields such as solar energy systems, chemical engineering processes, etc. [ABSTRACT FROM AUTHOR]

A theoretical analysis of a multi-phase fluid problem is presented in this paper. Electro-osmotic flow with heat transfer in a divergent channel is modeled. Jeffrey fluid is taken as the base liquid, which suspends with the spherical gold particles. Electromagnetohydrodynamic (EHD) of a two-phase fluid through a porous medium is influenced by thermal radiation. Cumbersome mathematical manipulations leads to yield an exact solution for the set of strenuous differential equations. A comprehensive parametric study validates the accuracy and formidability of this intuitive analysis, by confirming the corresponding boundary conditions. The investigation articulately describes that the momentum of two-phase flow is supported by the Jeffrey fluid parameter. Additional golden particles increase the velocity of the base liquid. However, more thermal energy has contributed to the variation of the Brinkman number B R M . Finally, thermal energy expunges from the diverse channel due to Jeffrey's fluid parameter. [ABSTRACT FROM AUTHOR]

This article recognizes the time-dependent axisymmetric flow of a non-Newtonian Williamson fluid caused by a radially stretching surface in the presence of nanoparticles in the porous medium. The combined impacts of Joule heating and viscous dissipation on the flow profiles are also discussed. Chemical reaction at the surface is implemented. The convective heat transfer model and Brownian motion are also studied for the electrically conducting nanofluid flow. The Williamson nanofluid flow has been modeled using a set of partial differential equations based on the fundamental conservation laws of mechanics. By using nondimensional quantities, these equations are first transformed into ordinary differential equations. The Galerkin weighted residual method is performed to resolve these equations numerically. Visual displays and detailed descriptions of the impacts of relevant variables on the thermal performance, concentration field, and velocity field are provided. It is noticed that the thermal profile enhances as the values of the Brownian motion parameter and temperature ratio parameter increase while declining when the values of the velocity slip parameter increase. The Biot number, activation energy, and unsteadiness parameters have proportional effects on the concentration profile, but the reaction parameter has inversely proportional effects on the concentration profile. Heat transfer rate increases with increasing the Weissenberg number and velocity slip parameter, drops with increasing the thermophoresis and unsteadiness parameters, and the Arrhenius activation energy. Finally, a comparison of the obtained numerical solution for the porous and nonporous medium are also done graphically and discussed in details. [ABSTRACT FROM AUTHOR]

The present work examines the convective Casson fluid flow over a stretching sheet with viscous dissipation and porous medium. The impact of thermal and mass transport is examined in terms of Soret and Dufour effects. The flow behaviour and heat transfer are investigated by subjecting the fluid to an induced magnetic field and suction/injection. The governing equations describing the flow problem are formulated using partial differential equations (PDEs). Similarity transformations are utilized to transform the governing equations into a system of ordinary differential equations (ODEs). Following that, the MATLAB solver bvp5c is utilized to grasp the results. Graphs serve as a function to display the consequences of flow on attributed parameters. Furthermore, the engineering properties such as skin friction, Nusselt number, and Sherwood number are represented through tables and graphs. Besides, the results of the present study are validated with the existing results, whereas a fine correspondence has been noticed. The findings show that the velocity of the fluid decreases by 8%, when the parameter of the induced magnetic field rises from 0.1 to 0.2. Similarly, a 3% decrement in the velocity profile is observed, while increasing the suction/injection parameter from 1.2 to 1.4. The temperature of the fluid is escalated for the increasing values of the Eckert number. Our analysis indicates a positive correlation between the Nusselt number and increasing Dufour number values. Similarly, the Sherwood number exhibits enhancement with a rise in the chemical reaction parameter. This combination has some applications in designing cooling systems for microfluidic devices, optimizing drag reduction in magnetohydrodynamics (MHD) devices, and developing novel separation processes. [ABSTRACT FROM AUTHOR]

A comprehensive study of the nature of micropolar fluid on an unsteady MHD-free convective transference through a perforated sheet is discussed considering the suction and Lorentz's force effects. The corresponding similarity equations of temperature, momentum, concentration, and angular momentum equations have been modified into the non-dimensional similarity equations of the temperature, momentum, concentration, and angular momentum equations by utilizing the similarity technique. The modified equations have been resolved by exerting the shooting technique with the help of the finite difference method (FDM) through MATLAB. The fluid flow is inversely proportional to the changes in micro rotational effect (Δ). The concentration boundary layer gets thinner as the Schmidt number (Sc) advances and hence the concentration of the fluid decreases. Micropolar fluid helps reduce drag forces and also acts as a coolant. The heat transmission rate advances by around 391%, and 110% due to growing amounts of Pr from 0.71 to 7.0, and v 0 from 0.6 to 3.0, respectively. The surface couple stress decays by about 33%, 45%, and 36% due to increasing values of M from 0.6 to 3.6, ∆ from 3.0 to 6.0, and λ from 0.1 to 1.2, respectively. [ABSTRACT FROM AUTHOR]

Understanding generalized Couette flow provides valuable insights into the behavior of fluids under various conditions, contributing to the advancement of more accurate models for real-world applications including tribology and lubrication, polymer and food processing, water conservation and oil exploration, microfluidics, biological fluid dynamics (blood flow in vessels), and electrohydrodynamic, and so on. The present study provided the exact asymptotic solution for the generalized Couette flow of a non-Newtonian Jeffrey fluid in a horizontal channel immersed in a saturated porous medium. The governing partial differential equations were transformed into a dimensionless form using the similarity technique and the resulting system of equations is solved by the Perturbation technique, as well as the method of the separation of variables, and computed on MATLAB (ode15s solver). The behavior of fluid velocity was investigated and presented through 2-D and 3-D graphs for two cases (i) when the implication of the magnetic field was strengthened and (ii) when the magnitude of the magnetic field was fixed but its degree of inclination was altered. The first-order chemical reactions and thermal radiation were also considered. Additionally, the effect of numerous emerging quantities on momentum, temperature, and concentration contours characterizing the fluid flow was depicted graphically and discussed. Furthermore, the skin friction (at different angles of inclination and magnetic strength), Nusselt number, and Sherwood number (at different time intervals) were evaluated at both boundaries and presented tabularly. The findings revealed that there was a decrease in the velocity profile with an increasing degree of inclination and strength of the magnetic field. Moreover, we observed an increment in thermal and mass flux when it was measured over time at both of the channels. Also, the outcomes predicted an oscillatory nature of shear stress at both of the boundries. [ABSTRACT FROM AUTHOR]

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This study addressed the compressible flow of viscous fluid in an asymmetric channel under peristalsis. The difference in amplitudes and phase of traveling waves created the asymmetry of channel. Simultaneous effect of magnetic field is also incorporated. Fluid flows through a porous medium. The analytical treatment of the solution is carried out by considering upper wall amplitude as the small parameter. The expressions of flow rate and net axial velocity are constructed for the second-order approximation. Numerical integration is employed to calculate net flow rate. The role of sundry parameters is illustrated graphically. Trapping phenomenon is also taken into account by plotting streamlines against sundry parameters. The significant finding of this study is that flow rate and axial velocity enhance as fluid transitions from hydrodynamic to hydromagnetic. Enhancement in the compressibility parameter trims down the velocity and the flow rate as well. Also, asymmetry of the channel causes an enhancement in the flow rate. This model is the most prevailing version of compressible flow under peristalsis through an asymmetric channel. The findings of this study have worth mentioning yields, which can be applicable in numerous areas of fluid dynamics and aircraft industry. [ABSTRACT FROM AUTHOR]

Hybrid nanofluid models have the potential to significantly enhance heat transport in many applications, like coolant of electric devices, thermal energy storage, and heat exchangers. Therefore, the existing problem deals with the simulation of heat and mass transport due to the three-dimensional hybrid nanoliquid flow amid two gyrating disks containing silver Ag and titanium oxide TiO2 nanoparticles. Further, a magnetic field is employed normally to flow’s direction. Applications of Darcy–Forchheimer law are discussed in terms of the porous medium. The utilization of the Cattaneo–Christov model is considered for analyzing heat and mass transmission. Additionally, the influence of thermal radiation, non-uniform heat sink/source, and Brownian diffusivity are discussed in the flow analysis. The problem is designed on the basis of the higher-order nonlinear PDEs which are then converted to ODEs using appropriate variables. Using the numerical technique known as the shooting technique in MATLAB, the reduced mathematical structure is solved numerically. From this study, it is analyzed that the axial velocity profile is weakened near the upper disk but the axial velocity profile is amplified near the lower for upsurge in the magnetic factor and porosity parameter. Hybrid nanofluid concentration is lower for higher Schmidt numbers. [ABSTRACT FROM AUTHOR]

This study focuses on how the porous medium affects the plume generated due to line heat source when an aligned magnetic field is present. For this study, the momentum equation of the flow model is modified for porous medium by including the porosity term. A mathematical model is developed as coupled partial differential equations in order to study the flow problem. Later, a numerical solution is found for the system of coupled partial differential equations that are transmuted in to ordinary differential equations. For this purpose, the numerical characteristics of the problem are derived employing a shooting approach in combination with the built-in MATLAB tool bvp4c. The graphical illustrations of missing and specified boundary conditions demonstrate the impacts of porosity parameter Ω, magnetic force parameter S, Prandtl number Pr and magnetic Prandtl number γ accompanied by a discussion of their corresponding physical implications. The novelty of this developed problem is proclaimed with justification by its emphasis on the principal characteristics of heat and fluid flow affected predominantly by the presence of a porous medium. The thorough examination of the porosity parameter Ω for missing conditions depicts that the temperature and velocity profiles enhance while current density drops for the increasing values of the porosity parameter Ω. Whereas, for specified conditions, the skin friction and magnetic flux enhance but heat transfer rate declines with increment in Ω. [ABSTRACT FROM AUTHOR]

This work examines the numerical representation of boundary layer flow across a horizontal plate using the non-Darcian Maxwell model. The inspiration of mass transfer, heat generation, the Soret effect, the non-Darcy effect, Arrhenius activation energy and thermal radiation are all covered in this study. The relevant similarity transformations are applied in primary equations and a built-in bvp4c program is employed for solutions. The effectiveness of the numerical approach is demonstrated by a thorough agreement with results that have been published in the past. The results are shown in tables and graphical representations that highlight multiple parameters including the non-Darcy parameter, Deborah number, magnetic parameter, Soret parameter, chemical reactions, activation energy, etc. Figures show that fluid velocity is enhanced by Deborah number whereas it slips due to non-Darcy parameter and magnetic parameter. Eckert number, Radiation enhances the temperature profile and slips due to the Prandtl number. Activation energy enhances the Concentration field but it declines due to chemical reaction. [ABSTRACT FROM AUTHOR]

Predicting the long‐term success of endovascular interventions in the clinical management of cerebral aneurysms requires detailed insight into the patient‐specific physiological conditions. In this work, we not only propose numerical representations of endovascular medical devices such as coils, flow diverters or Woven EndoBridge but also outline numerical models for the prediction of blood flow patterns in the aneurysm cavity right after a surgical intervention. Detailed knowledge about the postsurgical state then lays the basis to assess the chances of a stable occlusion of the aneurysm required for a long‐term treatment success. To this end, we propose mathematical and mechanical models of endovascular medical devices made out of thin metal wires. These can then be used for fully resolved flow simulations of the postsurgical blood flow, which in this work will be performed by means of a Lattice Boltzmann method applied to the incompressible Navier–Stokes equations and patient‐specific geometries. To probe the suitability of homogenized models, we also investigate poro‐elastic models to represent such medical devices. In particular, we examine the validity of this modeling approach for flow diverter placement across the opening of the aneurysm cavity. For both approaches, physiologically meaningful boundary conditions are provided from reduced‐order models of the vascular system. The present study demonstrates our capabilities to predict the postsurgical state and lays a solid foundation to tackle the prediction of thrombus formation and, thus, the aneurysm occlusion in a next step. [ABSTRACT FROM AUTHOR]

The influence of boundary layer flow of heat transfer analysis on hybrid nanofluid across an extended cylinder is the main focus of the current research. In addition, the impressions of magnetohydrodynamic, porous medium and thermal radiation are part of this investigation. Arrogate similarity variables are employed to transform the governing modelled partial differential equations into a couple of highly nonlinear ordinary differential equations. A numerical approach based on the BVP Midrich scheme in MAPLE solver is employed for solution of the set of resulting ordinary differential equations and obtained results are compared with existing literature. The effect of active important physical parameters like Magnetic Field, Porosity parameter, Eckert number, Prandtl number and thermal radiation parameters on dimensionless velocity and energy fields are employed via graphs and tables. The velocity profile decreased by about 65% when the magnetic field parameter values increases from 0.5 to 1.5. On the other hand increased by 70% on energy profile. The energy profile enhanced by about 62% when the Radiation parameter values increases from 1.0 < Rd < 3.0. The current model may be applicable in real life practical implications of employing Engine oil-SWCNTs-MWCNTs-TiO2 nanofluids on cylinders encompass enhanced heat transfer efficiency, and extended component lifespan, energy savings, and environmental benefits. This kind of theoretical analysis may be used in daily life applications, such as engineering and automobile industries. [ABSTRACT FROM AUTHOR]

In this paper, the entropy generation of natural convection Jeffrey fluid flow through an inclined porous channel is investigated by taking into account the impact of angled magnetic field, Soret parameter, thermal radiation, and Hall current. On the basis of simplified assumptions, the governing equations are transformed into dimensionless equations by using suitable transformations, and the spectral quasi-linearization method (SQLM) is used for the numerical solution. Graphs are utilized to address the effects of new thermophysical parameters. The calculations reveal that increasing the Soret parameter, inclination angle, Hall parameter, magnetic parameter, and Jeffrey fluid parameter induces an increase in entropy generation. Conversely, it decreases as the radiation parameter and channel angle of inclination increase. [ABSTRACT FROM AUTHOR]

Controllability of combustion characteristics in combustion systems, specifically for internal combustion engines, is vital for environmental compliance. This study experimentally investigated the simultaneous effects of the porous medium (PM) application and biodiesel addition on the spray and combustion characteristics of the gasoline–biodiesel blended fuel. A ring-shaped metal PM with 10 or 20 pores per inch pore density (PPI) is installed in a constant-volume combustion chamber for fuel injection through it. Varied blends of gasoline–biodiesel fuel (volume fraction: 5–15%) are tested at three different temperatures (750–1050 K). The results showed that the blended fuel spray interaction with the PM enhanced the fuel dispersion within the combustion chamber. The spray-projected area fraction increased by 4.4% and 28.2%, with the 10 and 20 PPI PM. The porous medium lowered the combustion pressure, temperature, heat release rate, extended ignition delay, and prolonged combustion duration, facilitating homogeneous combustion. The pressure decrease was around 12% and 59%, and the ignition delay increase was 223% and 263% for the 10 and 20 PPI PM. Conversely, biodiesel addition increased the combustion pressure, temperature, and heat release rate while reducing the ignition delay time. While the pressure increase was more than 100%, the PM reduced it by around 50%. The ignition delay reduction was around 50%, but the PM could increase it from 5 to 218%. Therefore, PM and biodiesel applications can be combined to address high emissions of gasoline–biodiesel blended fuel in free-spray combustion and the prolonged ignition delay associated with PM. [ABSTRACT FROM AUTHOR]

AbstractEnclosures that contain both fluid and porous regions are utilized in various industries and geophysical processes to enhance heat and mass transfer. These enclosures find applications in fields such as geothermal engineering, drying of porous solids, cooling of electronics, metal solidification, and many others. In line with the motivation behind these applications, the present study explores double diffusion in the naturally convective flow of water-based nano fluid saturated in the trapezoidal porous enclosure and containing Copper (Cu) nano particles. The impact of uniformly applied radiative heat flux and nano particle shape factor is also accounted. A numerical investigation was carried out using a finite difference methodology integrated into a computational MATLAB code for numerical simulation. The simulation aimed to study the effect of nanoparticle shape factor on the effectiveness of a porous medium, which is exposed to two distinct objectives: enhancing heat transfer and optimizing mass transfer within a fluid-saturated porous medium. This research conducts a meticulous parametric exploration, underscoring the pivotal roles played by Darcy number (Da), nanofluid shape factor (m), Rayleigh number (Ra), thermal radiation (Rd), buoyancy ratio (Nr), and Lewis number (Le) in shaping the dynamics of flow, heat, and concentration transfer. The analysis of Nusselt and Sherwood numbers reveals that changing the shape of nano-particles from spheres to bricks increases the heat flux and mass flux coefficients by approximately 0.33% and 1.37% respectively. The results show a significant increase in Nusselt and Sherwood numbers, with blade-shaped nanoparticles demonstrating approximately a 2.97% and 10.82% improvement, respectively, compared to sphere-shaped nanoparticles. The outcome of this analysis yields an exhaustive dataset encompassing Nusselt and Sherwood numbers can be written as mathematical functions based on the parameters we talked about earlier. [ABSTRACT FROM AUTHOR]

AbstractInspired by the numerous applications of non-Newtonian nanomaterials in science and industries, the two-dimensional convective hydromagnetic movement in a micropolar nanofluid within an expanding permeable surface with the existence of binary chemical reaction and convective boundary constraints is examined in this study. Thermal radiation, energy generation, and activation energy interactions are employed to handle the nanofluid flow. The underlying equations are transformed via the similarity transitions into an array of non-linear ODE. The BVP4C MATLAB package is applied to solve the system of equations numerically. The necessary outcomes of the micropolar fluid velocity, micro-rotation, temperature, concentration, friction factor, mass transfer, and heat transfer rates are shown graphically and thoroughly analyzed quantitatively. The micropolar nanofluid’s mobility is reduced by the heating and solutal Grashof numbers. It is noted that the magnetic coefficient decreases velocity, it has the opposite impact on the degree of temperature. The plotted outcomes also show that the temperature increases as the increase in stimulation radiation variable. Meanwhile, the thermal field exhibits strengthen as the intensity of Biot number and Eckert number responses enhances. The growth of the activation energy leads to a noticeable enrichment in the concentration profile. [ABSTRACT FROM AUTHOR]

The current work investigates the effects of oblique Lorentz force and Navier's slip boundary condition on unsteady hybrid nanoliquid flow with three different base liquids (H2O, CH3OH and H2O–EG) across a nonlinearly elongating surface set in a porous medium. This research considers the effects of viscous–Ohmic dissipation, nonlinearly variable thermal radiation, internal heat source, the Soret effect, first-order chemical reaction and thermal and solutal jump conditions at the boundary. Proper thermo-physical relationships for the hybrid nanoliquid have been established. Rosseland's estimate for an optically thick regime is used when calculating the heat flow owing to radiation. The dimensional governing equations are translated into nondimensional forms using appropriate similarity transformations. The velocity, energy and concentration fields are numerically solved using a shooting strategy based on the secant iteration and the Runge–Kutta–Fehlberg method. The physical implications of several essential parameters on the hybrid nanoliquid velocity, temperature and concentration are investigated using graphical and tabular representations of numerical data. Furthermore, the multiple (quadratic) regression analysis reveals that physical parameters strongly influence the local skin friction coefficient, Sherwood and Nusselt numbers. For continuously growing values of the unsteadiness parameter, the velocity, thermal and concentration scattering declined everywhere within the boundary layer region. [ABSTRACT FROM AUTHOR]

AbstractThis research is conducted to investigate the heat transfer analysis in a two-phase fluid model under the impact of an electric double layer and magnetic field through two types of geometries with porous media. The Darcy model is used to capture the effect of porous medium. The perturbation technique is employed to produce the analytical solution of fluid and particulate velocities, temperature distribution, volumetric flow rate, and stream function. The computational revealed that the two-phase model produces 32 and 36% greater heat transfer as compared to the single-phase model by considering convergent and divergent channels, respectively. It is observed that the divergent channel provides 4% more heat transfer as compared to the convergent channel. The present study will offer valuable insights into the electric double-layer dynamics of two-phase fluid through complex configurations, such as biomedical engineering. The current two-phase model is also very important and applicable in electrofluidic dynamic and biomedical engineering where biomedical electronic devices such as two-phase lab-on-chip may be engineered. [ABSTRACT FROM AUTHOR]

This article aims to examine an unsteady 2-D laminar flow of magnetohydrodynamic fluid caused by an elastic surface immersed in a permeable medium under the influence of thermal radiation and extended heat flux. Thermal conductivity and viscosity both are supposed to vary with temperature. This flow model also includes velocity slip, heat source, and joule heating. The governing equations of the fluid, including momentum and energy equations, of the proposed problem are transfigured into a system of interconnected non-linear ordinary differential equations through similarity transformations. The resultant equations are solved efficiently by employing the shooting technique in combination with the fourth-order Runge-Kutta method. Numerical values and the effect of numerous governing factors on the flow field, temperature distribution, local skin friction coefficient, and Nusselt number are showcased via graphs and tables. The investigation reveals that velocity slip, heat source, and porosity parameters enhance the temperature field while diminishing the velocity field. Furthermore, the velocity slip parameter notably reduces both the coefficient of skin friction and the Nusselt number. [ABSTRACT FROM AUTHOR]

AbstractTrihybrid nanofluid exhibits significantly higher thermal conductivity compared to individual nanoparticles. This enhanced thermal conductivity is especially notable at low concentrations, leading to improved heat transfer efficiency. Hence, trihybrid nanofluids have potential practical applications in various heat transfer systems, cooling, and heating processes. This study investigates the entropy-based thermal aspects of MHD trihybrid nanofluid composed of MgO, TiO2, and CoFe2O4 nanoparticles in combination with water as the base fluid. The analysis is conducted between two parallel plates that are subjected to squeezing motion. Novel aspects encompassing thermal radiation, viscous dissipation, reaction, and temperature-dependent viscosity are taken into consideration. The governing PDEs are transformed into a system of ODEs using appropriate similarity transformations. The numerical solution is achieved through the implementation of the RKF method with a shooting technique. The effects of emerging parameters on velocity, temperature, concentration profiles, and engineering quantities are investigated and discussed through graphs and tables. The outcomes indicate that suction and magnetic fields cause a 7.50% decrease in nanofluid velocity due to augmented squeezing and medium factors. The temperature increases by 8% in trihybrid nanofluids with stronger radiation. An increase in the reaction leads to a decrease in the concentration of CoFe2O4/H2O nanofluid by 5.53%. An escalation in the Brinkman number results in simultaneous increments of 6.04% in entropy and 4.83% in the Bejan number. Magnetic field strength reduces friction by 2.46% on both plates. Enhancing the radiation parameter leads to a 7.31% rise in heat transfer at the lower plate, but it declines by 4.49% at the upper plate. Higher concentration ratios lead to 5% higher Sherwood numbers on both plates. [ABSTRACT FROM AUTHOR]

The heat and mass transfer phenomenon in the presence of a moving magnetic field has a wide range of applications, spanning from industrial processes to environmental engineering and energy conversion technologies. Understanding these interactions enables the optimization of various processes and the development of innovative technologies. This manuscript is about a non-integer-order heat-mass transfer model for Maxwell fluid over an inclined plate in a porous medium. The MHD flow of non-Newtonian fluid over the plate due to the natural convection of the symmetric temperature field and general motion of the inclined plate is investigated. A magnetic field is applied with a certain angle to the plate, and it can either be fixed in place or move along with the plate as it moves. Our model equations are linear in time, and Laplace transforms form a powerful tool for analyzing and solving linear DEs and systems, while the Stehfest algorithm enables the recovery of original time domain functions from their Laplace transform. Moreover, it offers a powerful framework for handling fractional differential equations and capturing the intricate dynamics of non-Newtonian fluids under the influence of magnetic fields over inclined plates in porous media. So, the Laplace transform method and Stehfest's numerical inversion algorithm are employed as the analytical approaches in our study for the solution to the model. Several cases for the general motion of the plate and generalized boundary conditions are discussed. A thorough parametric analysis is performed using graphical analysis, and useful conclusions are recorded that help to optimize various processes and the developments of innovative technologies. [ABSTRACT FROM AUTHOR]

• The reflection/transmission of seismoelectric waves propagating through a sandwiched structure are studied. • A new fractional order viscoelastic model with two attenuation peaks at seismic and sonic frequencies is established. • The seismoelectric effects have noticeable influences on EM wave while negligible influences on seismic waves. • The porosity and the viscoelasticity of solid frame have evident influences on both elastic waves and EM waves The seismoelectric waves generated in a fluid-saturated porous interlayer and the reflection/transmission characteristics at the interfaces of sandwiched structure are studied in this paper. Aiming to describe the strong attenuation and dispersion simultaneously at seismic and sonic frequencies, a new fractional viscoelastic model for the solid skeleton is introduced to the Pride's seismoelectric coupling theory. Using the interfacial continuity of stress, displacements, magnetic and electric fields, the reflection/transmission coefficients are determined. The numerical results are provided and shown graphically. The effects of seismoelectric coupling and the viscoelastic characteristics of solid skeleton on the reflection and transmission of seismoelectric waves are mainly studied. It is observed that the thickness, porosity and the viscoelastic characteristics of solid skeleton have evident effects not only on the electromagnetic waves but also on the seismic waves. [ABSTRACT FROM AUTHOR]

The present article deals with the influence of the local thermal nonequilibrium (LTNE) state on natural convection in an enclosure filled with nanofluid-saturated porous medium. The flow is induced due to the maintenance of constant heat flux on the vertical walls and insulation of horizontal walls. The Darcy model has been adopted to describe the flow governing equations. These equations are solved numerically by using the alternate direction implicit method and analytically by applying parallel flow assumptions valid for large aspect ratios. Boundary layer analysis is performed to report the boundary layer thickness (δ x ∼ 2 1 / 2 (k nf / k f) 1 / 10 (R a T) − 1 / 5) as well as the heat transfer rate of nanofluid ( N u nf ∼ (k nf / k f) − 1 / 5 R a T 2 / 5). The combined effect of LTNE state parameters (interface heat transfer coefficient (H), porosity scaled thermal conductivity ratio (γ)) and volume fraction of nanoparticle ( ϕ ) is addressed on the flow dynamics and heat transfer mechanism. Rigorous analysis, indicates that the average heat transfer rate of nanofluid and solid porous matrix are increasing function of H and γ, however, the role of γ is accelerated for a relatively high value of H. For increasing the value of γ from 1 to 10, the enhancement in the heat transfer rate of nanofluid is reported to be up to 27% at 10% volume fraction of nanoparticles. The average Nusselt number of nanofluid, as well as solid phase, are reduced when the value of ϕ is increased under the LTNE circumstances. Furthermore, the flow structure is controlled by unicellular structure with rotating anticlockwise direction in the entire study. For the very small value of H the temperature distribution in the solid porous matrix is mainly by conduction mode and distribution is linear, however, for a relatively high value of H the distribution in the same is controlled by both conduction as well as convection, and it will be more pronounced for the higher value of γ. [ABSTRACT FROM AUTHOR]

An evaluation method for the initial penetration of molten cast iron into the sand mold was suggested based on the laboratory-scale penetration experiments for the cast iron. The horizontal penetration depth of the molten cast iron into the sand core was analyzed using the capillary model. The early stage of the penetration was discussed, and it was clarified that the penetration is not stopped by the solidification but is stopped by the decreasing of the equivalent pore radius. It was explained that the equivalent pore radius decreases with increasing the penetration depth, and the penetration is stopped when the critical pressure, i.e., the pressure required for the penetration, becomes higher than the pressure which is acting on the penetration front. Based on the analysis, an evaluation method of the penetration of depth at the early stage of the penetration was suggested. The analysis method was applied for the other type of metals (mercury and steel) as well, and reasonable results were obtained. A simplified finite-element model of liquid iron penetration into a sand core was developed, accounting for heat exchange between the melt and the porous medium, at different pore geometries. [ABSTRACT FROM AUTHOR]

In the current work, slip and radial magnetic field effects are taken into consideration as they relate to a comparison examination regarding two-dimensional heat transfer caused on the basis of the free convective flow of a Casson (non-Newtonian) fluid in electro-conductive and non-Darcy porous medium of a horizontal circular cylinder. The formulation has been created, and the boundary layer equations are then transformed using similarity transformations into a self-similar form. Using the Keller box method (KBM), a nonlinear boundary value that is simplified issue is numerically resolved, the momentum and temperature equations, higher-order partial differential equation to first-order partial differential equation. Graphs are used to show the numerical solutions for Nusselt number, skin friction coefficient, velocity profile, and temperature profile. With graphs and tables, the impact of key variables, rate of heat transfer, and skin irritation are measured. The flow of the fluid is the most interesting aspect of the analysis; the outcome shows that Casson fluid velocity fields are reduced by an increase in magnetic number and nonuniform heat source/sink, radiation parameter, and when it comes to magnetic number variation. Increase in magnetic body force parameter (H) values results in decreases in the component of velocity. Skin friction coefficient and Nusselt number rise at high Newtonian slip (SF), non-Darcy parameter (Da), and Prandtl number (Pr) values. [ABSTRACT FROM AUTHOR]

Solar collectors are devices that transform solar irradiation energy into thermal energy for various purposes. Among different solar thermal collectors, solar dish collectors are remarkable for having the highest solar-to-thermal energy conversion efficiency. These collectors are available with various receiver shapes like external, cavity, spiral and volume receivers. Notably, cavity receivers, with their unique structure, exhibit superior efficiency compared to other receiver types. Recently, researchers have explored different shapes of cavity receivers, such as triangle, circular, square and hexagonal, to enhance thermal efficiency. In light of this, the present study investigates the heat transfer behavior occurring in an inclined permeable triangular enclosure with heated fins, using a (Ag–TiO2/H2O) hybrid nanofluid as the working fluid. The mathematical modeling of hybrid nanofluid flow within the triangular enclosure is accomplished using the Navier–Stokes equations under the Boussinesq approximation, and dimensionless governing equations are solved through an in-house MATLAB code integrated with a finite difference method. The findings indicate that enhancing the Rayleigh number, thermal radiation and magnetic field boosts the heat transfer rate for a nanoparticle volume fraction of 5%. A decrease in the Darcy number leads to a shift in the flow pattern, causing the vortex cell to relocate to the top left. Higher values of Rayleigh number and thermal radiation effects are associated with a superior average heat transfer rate. Comparatively, the average heat transfer rate is slightly greater in an inclined cavity with α = π / 2 compared to an uninclined cavity. This emphasizes the focus of numerous studies on nanofluid flow in inclined square cavities, particularly in the context of solar energy. [ABSTRACT FROM AUTHOR]

The present work deals with a study of non-Newtonian Casson and Williamson nanofluids flow models with a linearly porous stretching sheet across convective conditions. The heat transfer phenomenon has been explored under the impacts of heat source, radiation and viscous dissipation. The higher-order chemical reaction and suction/injection are also taken into consideration. The system of nonlinear dimensionally governing PDEs are converted into dimensionless nonlinear ODEs with the use of appropriate similarity transformations. The transformed set of ODEs are numerically solved by using R–K Fehlberg approach based on shooting technique. The graphical representations for physical parameters are plotted using the in-built MATLAB solver bvp5c. Additionally, the numerical tabular values calculated for the skin friction coefficient, heat transfer rate and mass transfer rate. It is noticed that with elevated amounts of magnetic field, Brownian motion parameter, heat generation and thermal radiation, the temperature significantly increases. The velocity increases with increased thermal and mass Grashof numbers, and the reverse phenomenon exists with increasing magnetic field, porous medium and suction. The Williamson nanofluid velocity is less significant than the Casson nanofluid velocity. The concentration drops while enhancing the higher-order chemical reaction and Schmidt number. Moreover, the increment in the radiation and Biot number increases the Nusselt number. [ABSTRACT FROM AUTHOR]

Our present study intends to examine the unsteady thin film flow and heat transfer of Ag - H 2 O nanofluid on a stretching sheet embedded in a porous medium. Radiative heat, Ohmic heating with slip, and convective boundary conditions are taken into account. The effect of various nanoparticle shape factors is also investigated. Nanofluid thermal conductivity depends on nanoparticle shape. The primary time-dependent equations are transformed using similarity transformation and solved using a prominent Runge–Kutta fourth-order and shooting iterative process. Graphs and numerical values of physical factors pertinent to fluid flow are obtained using MATLAB software. The skin friction coefficient and the heat transfer rate are also investigated and tabulated. Results reveal that magnetic, porosity, and unsteady parameters all have a diminishing impact on velocity profiles. Radiation parameter has a positive impact on temperature distribution, while an opposite trend is observed for magnetic fields. Findings indicate that magnetic field and porosity enhance the skin friction coefficient, whereas heat transfer rate increases with Biot number and slip parameter. Platelet-shaped nanoparticles are shown to be the most efficient in heat transfer. The outcomes were compared to previously reported results and found excellent agreement. [ABSTRACT FROM AUTHOR]

This research work reports the boundary layer flow behavior and heat transfer properties of Maxwell fluid across an exponentially stretched sheet. Thermal radiation, porous media, and heat generation\absorption factors are incorporated into the simulation of flow equations. More specifically, an impact of induced magnetic field (IMF) is implemented to analyzing the magneto-hydrodynamics (MHD) flow. This provides a profound effect on fluid flow design, thus, it is necessary to control the nature of the flow rate more precisely. By implementing the necessary transforms, the requisite system of ordinary ones is accomplished. BVP4C scheme is executed to solve nonlinear systems. The effects of the physical model are tabulated and graphically shown. We presented dual solutions by comparing the results of Maxwell's fluid with the Newtonian fluid. Some of the important conclusions are that for enhanced values of the magnetic parameter, the induced magnetic field becomes stronger and a reverse effect occurs, when the reciprocal Prandtl number becomes larger. Radiation and heat source/sink parameter accelerate temperature, which has the opposite effect on Prandtl number. Furthermore, velocity curve intensifies for higher estimation of magnetic and porosity variables. It is also noteworthy to make a comparison between previously available results and the current outcomes under certain conditions. The assessments are, therefore, considered to be in perfect agreement. [ABSTRACT FROM AUTHOR]

The present investigation focused on the influence of magnetohydrodynamic Gold-Fe3O4 hybrid nanofluid flow over a stretching surface in the presence of a porous medium and linear thermal radiation. This article demonstrates a novel method for implementing an intelligent computational solution by using a multilayer perception (MLP) feed-forward back-propagation artificial neural network (ANN) controlled by the Levenberg-Marquard algorithm. We trained, tested, and validated the ANN model using the obtained data. In this model, we used blood as the base fluid along with Gold-Fe3O4 nanoparticles. By using the suitable self-similarity variables, the partial differential equations (PDEs) are transformed into ordinary differential equations (ODEs). After that, the dimensionless equations were solved by using the MATLAB solver in the Fehlberg method, such as those involving velocity, energy, skin friction coefficient, heat transfer rates and other variables. The goals of the ANN model included data selection, network construction, network training, and performance assessment using the mean square error indicator. The influence of key factors on fluid transport properties is presented via tables and graphs. The velocity profile decreased for higher values of the magnetic field parameter and we noticed an increasing tendency in the temperature profile. This type of theoretical investigation is a necessary aspect of the biomedical field and many engineering sectors. [ABSTRACT FROM AUTHOR]

Copyright of Tunnel Construction / Suidao Jianshe (Zhong-Yingwen Ban) is the property of Tunnel Construction Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The microstructure, mineral composition, total organic carbon content, etc., of gas shale are crucial parameters for shale reservoirs, which can directly/indirectly affect shale brittleness, fracturing effect, adsorption ability and production efficiency. The study proposed a workflow to characterize the physical and mechanical parameters of Lower Silurian Longmaxi shale outcrop samples extracted from the favorable block in Changning, Sichuan, southwest China. This study elaborated on the influence of these physical and mechanical characteristics and proposed a corresponding brittleness index on shale extraction. In addition, it put forward corresponding suggestions for development and risk control. For a better understanding the mechanisms of shale gas storage and production, XRD, XRF, SEM, low temperature Nitrogen adsorption method, nuclear magnetic resonance and other measurements were employed to analyze and study the mineral composition, microstructure, and adsorption performance of shale. The results demonstrated that the pores of shale are mainly slit pores; there are diverse pore types in shale, mainly including intergranular pores, mineral particle dissolution pores, and internal pores of organic matter; The samples with relatively low porosity also noticeably exhibit ultra-low permeability, and the nanopore structure is remarkably significant, with distribution primarily in range of 5-237 nm. Finally, a brittleness index considering the influence of water content and the mechanical properties was proposed, and the coupling interaction of various minerals components and mechanical properties on the brittleness index can more objectively reflect the brittleness characteristics of deep shale formation. [ABSTRACT FROM AUTHOR]

We analytically investigated the magnetohydrodynamic motions of electrically conductive, incompressible Oldroyd-B fluids through an infinite circular cylinder filled with a porous medium. A general expression was established for the dimensionless velocity of fluid as a cylinder moves along its symmetry axis with an arbitrary velocity; the expression can generate exact solutions for any motion of this fluid type, solving the discussed problem. Special cases were considered and validated through graphical investigation to illustrate important characteristics of fluid behavior. In application, this is the first presentation of an exact general expression for non-trivial shear stress related to the magnetohydrodynamic motions of Oldroyd-B fluids when a longitudinal time-dependent shear stress is applied to the fluid by a cylinder. Solutions for the motions of rate-type fluids are lacking. The graphical representations show that in the presence of a magnetic field or porous medium, fluids flow more slowly and the steady state is reached earlier. [ABSTRACT FROM AUTHOR]

Copyright of Baghdad Science Journal is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Baghdad Science Journal is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)