Search

Purpose: The present findings aim to investigate the thermal behavior of water-based nanofluid flow over a rotating surface, focusing on understanding the effects of different types of nanoparticles on thermal efficiency, considering thermal radiation and variable viscosity effects. By considering four distinct nanoparticles – silicon dioxide titanium dioxide, aluminum oxide and molybdenum disulfide – the study aims to provide insights into how nanoparticle addition influences heat production, thermal boundary layer thickness and overall thermal performance. Design/methodology/approach: The study employs computational methods, utilizing the BVP mid-rich algorithm for the solution procedure. The computational approach allows for a detailed investigation of the thermal behavior of nanofluid flows across a rotating surface under varying conditions. Findings: The study concludes that adding nanoparticles in the base liquid increases heat production in the system, resulting in enhanced thermal boundary layer thickness. The comparative analysis shows that different nanoparticle types exhibit varying effects on thermal efficiency, suggesting that careful selection of nanoparticles can optimize heat transport and thermal management processes. Moreover, there's a noteworthy uptrend in the radial velocity profile concerning the stretching parameter, whereas a converse trend is observed in the thermal profile. Originality/value: This study contributes original insights by comprehensively investigating the thermal behavior of water-based hybrid nanofluid flow over a rotating surface. [ABSTRACT FROM AUTHOR]

AbstractBoundary layer separation is a common challenge in fluid dynamics, where flow separates from a surface due to adverse pressure gradients. Transpiration, the injection or suction of fluid through a surface, is a technique used to mitigate this issue. This study investigates transpiration’s effects on boundary layer separation over a stretching wedge conveying ternary hybrid nanoparticles, which is crucial for optimizing various engineering systems. The study establishes a mathematical model incorporating transpiration, dual stretching, viscous dissipation, and nanoparticle volume fractions. The model is reduced to ordinary differential equations using similarity transformations and then solved numerically with MATLAB’s bvp4c package. Here, the convective heat transfer increases with suction and decreases with blowing due to changes in boundary layer thickness. This insight provides valuable information for engineers seeking to control temperature gradients in their systems. Moreover, the study highlights transpiration’s efficacy in mitigating boundary layer separation induced by adverse pressure gradients. Furthermore, flow enhancement with blowing depends on specific conditions, such as the value of the blowing parameter, highlighting its nuanced influence. [ABSTRACT FROM AUTHOR]

In this research, the dynamics of MHD Casson fluid flow has been discussed in the presence of non-Darcy Forchheimer porous medium. The investigation is focused on how thermal radiation, Soret–Dufour, and chemical reactions affect the incompressible Casson flow in a non-Darcy Forchheimer porous medium, taking account of pressure force. The mathematical model of the system is solved using the finite difference scheme followed by the shooting technique with bvp4c tool in MATLAB. The effects of physical parameters on velocity and transport (heat and mass) profile are illustrated through graphs. From the results, it is observed that Soret effect reduces the thermal boundary layer thickness which leads to the asymptotic increase in heat dissipation. The findings of the study on MHD Casson fluid model considering the non-Darcy Forchheimer porous medium are useful in engineering and science areas such as chemical machinery systems, geophysics, etc. [ABSTRACT FROM AUTHOR]

Dynamic changes in astrocyte Ca2+ are recognized as contributors to functional hyperemia, a critical response to increased neuronal activity mediated by a process known as neurovascular coupling (NVC). Although the critical role of glutamatergic signaling in this process has been extensively investigated, the impact of behavioral state, and the release of behavior-associated neurotransmitters, such as norepinephrine and serotonin, on astrocyte Ca2+ dynamics and functional hyperemia have received less attention. We used two-photon imaging of the barrel cortex in awake mice to examine the role of noradrenergic and serotonergic projections in NVC. We found that both neurotransmitters facilitated sensory stimulation-induced increases in astrocyte Ca2+. Interestingly, while ablation of serotonergic neurons reduced sensory stimulation-induced functional hyperemia, ablation of noradrenergic neurons caused both attenuation and potentiation of functional hyperemia. Our study demonstrates that norepinephrine and serotonin are involved in modulating sensory stimulation-induced astrocyte Ca2+ elevations and identifies their differential effects in regulating functional hyperemia. Noradrenergic and serotonergic signaling are involved in modulating sensory stimulation-induced astrocyte Ca2+ dynamics, and each signaling pathway alters functional hyperemia differently. [ABSTRACT FROM AUTHOR]

The prime concern of the present investigation includes a numerical approach targeting the study of heat and mass transfer for the flow of magnetic nanofluid based on hydrocarbon (C1-20B) past a rotating porous disk taking into cognizance the various parameters present. The modelled system of equations for the unsteady flow is rendered into the dimensionless non-linear system of differential equations, via suitable transformations. The modelled system of dimensionless equations is numerically solved by MATLAB bvp4c solver. The influence of involved emerging parameters, namely permeability, viscosity variation, rotation, radiation, ferrohydrodynamic interaction, thermophoresis, and Brownian motion parameters on flow regimes has been studied and shown graphically. Moreover, numerical data of the rate of heat and mass transfer and coefficients of skin friction are also mentioned in tabular form. It is found that the tangential velocity is reduced for increasing the value of viscosity variation parameters. The fluid temperature profile shows an increment when we increase the rotation of the disk. [ABSTRACT FROM AUTHOR]

Considering the Navier Stokes equations paired with the heat equation for ferrohydrodynamic flow of magnetic nanofluid amidst two rotating porous disks, nothing is known on the significance of geothermal viscosity for the magnetic fluid flow between co-rotating porous surfaces. The current analysis considers the effects of changing viscosity and thermal radiation. Additionally, the stretching and angular velocities of the two disks differ. The flow model's estimated basic equations are transformed into nondimensional ordinary differential equations (ODEs) with the proper transformation before being numerically solved using Maple's built-in BVP Midrich approach. For velocity and temperature fields, the effects of active flow parameters such as the depth-dependent viscosity variation parameter, ferro-hydrodynamics interaction parameter, Reynolds number, Prandtl number, Darcy number, Eckert number, and radiation parameter are discussed. It is worth noticing that the temperature field tends to decline as the Darcy parameter is higher estimated. It is worth concluding that there exists a high fluctuating viscosity around the lower disk, the magnitude of horizontal velocity decreased, but vertical velocity increased everywhere else. Furthermore, skin friction becomes more valuable at higher Reynolds numbers and porosity estimates. [ABSTRACT FROM AUTHOR]

An investigation has been carried out on heat and mass transport phenomena for mixed-convection flow over a vertically non-Darcy Forchheimer porous stretching/shrinking sheet considering the Soret - Dufour effects. With consideration of the appropriate similarity framework, the fundamental governing flow equations are converted into a system of non-dimensional equations. The bvp4c, a built-in solver of MATLAB software, is utilized to compute the numerical results of the flow problem. The present model is validated with previously published literature. The impacts of several related flow parameters on velocity, temperature, and concentration profiles have been displayed graphically. Also, the mass and heat transfer rates along with the coefficients of skin friction are calculated and discussed numerically. It is found that an increment in the thermal radiation parameter increases the fluid temperature, and the concentration gradient boosts up for the enhancement of the Soret number. [ABSTRACT FROM AUTHOR]

The current study computationally investigates the thermally radiative incompressible flow of hybrid nanofluid induced by a radially stretchable rotating disk with entropy generation analysis. The temperature-dependent viscosity of hybrid nanofluid, stretching of the disk, chemical reaction, Joule, and viscous dissipation effects are incorporated in the formulation of the mathematical flow model. In this study, Karman's transformations are used to convert the governing equations of partial derivative form into their ordinary derivative form, which is evaluated numerically together with boundary conditions using the BVP Midrich technique built-in Maple software. The impacts of variable viscosity parameter, magnetic field parameter, radiation parameter, Eckert number, Prandtl number, Biot Number, and chemical reaction parameter on flow-field factors and entropy generation rate are presented graphically. The outcomes indicate that higher estimations of magnetic field parameter and entropy generation rate increase the velocity distribution. Also, an increment in Schmidt number and chemical reaction parameter diminishes hybrid fluid concentration, and a higher magnetic field parameter maximizes the same. This study is significant in industrial thermal management and heat transport increment in renewable energy systems. [ABSTRACT FROM AUTHOR]