121 research outputs found

    Hall Effect on Two-Phase Laminar Boundary Layer flow of Dusty Liquid due to Stretching of an Elastic Flat Sheet

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    The present investigation is concerned with the effect of Hall current on boundary layer two-phase flow of an electrically conducting dusty fluid over a permeable stretching sheet in the presence of a strong magnetic field. The boundary layer approximation is employed for mathematical modeling. The governing partial differential equations are reduced to a set of ordinary differential equations using suitable similarity transformations. Subsequent equations are solved numerically by using Runge-Kutta-Fehlberg fourth-fifth order method. A comprehensive parametric study is conducted to reveal the tendency of solutions. It is found that the mass concentration of dust particles can be used as a control parameter to control the friction factor at the sheet. The influence of suction and injection are opposite on the momentum boundary layer growth

    Unsteady squeezing flow of a magnetized nano-lubricant between parallel disks with Robin boundary conditions

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    The aim of the present work is to examine the impact of magnetized nanoparticles (NPs) in enhancement of heat transport in a tribological system subjected to convective type heating (Robin) boundary conditions. The regime examined comprises the squeezing transition of a magnetic (smart) Newtonian nanolubricant between two analogous disks under an axial magnetism. The lower disk is permeable whereas the upper disk is solid. The mechanisms of haphazard motion of NPs and thermophoresis are simulated. The non-dimensional problem is solved numerically using a finite difference method in the MATLAB bvp4c solver based on Lobotto quadrature, to scrutinize the significance of thermophoresis parameter, squeezing number, Hartmann number, Prandtl number and Brownian motion parameter on velocity, temperature, nanoparticle concentration, Nusselt number, factor of friction and Sherwood number distributions. The obtained results for the friction factor are validated against previously published results. It is found that friction factor at the disk increases with intensity in applied magnetic field. The haphazard (Brownian) motion of nanoparticles causes an enhancement in thermal field. Suction and injection are found to induce different effects on transport characteristics depending on the specification of equal or unequal Biot numbers at the disks. The main quantitative outcome is that, unequal Biot numbers produce significant cooling of the regime for both cases of disk suction or injection, indicating that Robin boundary conditions yield substantial deviation from conventional thermal boundary conditions. Higher thermophoretic parameter also elevates temperatures in the regime. The nanoparticles concentration at the disk is boosted with higher values of Brownian motion parameter. The response of temperature is similar in both suction and injection cases; however, this tendency is quite opposite for nanoparticle concentrations. In the core zone, the resistive magnetic body force dominates and this manifests in a significant reduction in velocity i.e. damping. The heat buildup in squeeze films (which can lead to corrosion and degradation of surfaces) can be successfully removed with magnetic nanoparticles leading to prolonged serviceability of lubrication systems and the need for less maintenance

    Thermal Marangoni convection in two-phase flow of dusty Casson fluid

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    This paper deals with the thermal Marangoni convection effects in magneto-Casson liquid flow through suspension of dust particles. The transpiration cooling aspect is accounted. The surface tension is assumed to be fluctuating linearly with temperature. The fluid and dust particle’s temperature of the interface is chosen as a quadratic function of interface arc length. The governing problem is modelled by conservation laws of mass, momentum and energy for fluid and dust particle phase. Stretching transformation technique is utilized to form ordinary differential equations from the partial differential equations. Later, the numerical solutions based on Runge-Kutta-Fehlberg method are established. The momentum and heat transport distributions are focused on the outcome of distinct governing parameters. The results of Nusselt number is also presented and discussed. It is established that the heat transfer rate is higher in the case of dusty non-Newtonian fluid than dusty Newtonian fluid. The rate of heat transfer can be enhanced by suspending dust particles in a base liquid. Keywords: Marangoni convection, Dusty fluid, Casson fluid, Two-phase flow, Runge-Kutta-Fehlberg metho

    Scrutinization of thermal radiation, viscous dissipation and Joule heating effects on Marangoni convective two-phase flow of Casson fluid with fluid-particle suspension

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    The impact of Marangoni convection on dusty Casson fluid boundary layer flow with Joule heating and viscous dissipation aspects is addressed. The surface tension is assumed to vary linearly with temperature. Physical aspects of magnetohydrodynamics and thermal radiation are also accounted. The governing problem is modelled under boundary layer approximations for fluid phase and dust particle phase and then Runge-Kutta-Fehlberg method based numeric solutions are established. The momentum and heat transport mechanisms are focused on the result of distinct governing parameters. The Nusselt number is also calculated. It is established that the rate of heat transfer can be enhanced by suspending dust particles in the base fluid. The temperature field of fluid phase and temperature of dust phase are quite reverse for thermal dust parameter. The radiative heat, viscous dissipation and Joule heating aspects are constructive for thermal fields of fluid and dust phases. The velocity of dusty Casson fluid dominates the velocity of dusty fluid while this trend is opposite in the case of temperature. Moreover qualitative behaviour of fluid phase and dust phase temperature/velocity are similar. Keywords: Marangoni convection, Dusty fluid, Casson fluid, Joule heating, Viscous dissipation, Two-phase flow, Thermal radiatio

    Significance of inclined magnetic field on nano-bioconvection with nonlinear thermal radiation and exponential space based heat source: a sensitivity analysis

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    The characteristics of heat transport in nanoliquids under the influence of bio-convection (motile microorganism) have significant applications, since nanoliquids have greater capacity to improve heat transport properties than conventional liquids. With these incredible nanoliquid characteristics, the main objective of current research is to examine the impact of the exponential heat source linked to space and the inclined magnetic force on the nano-bioconvective flow between two turntables. The effect of nonlinear thermal radiation, variable thermal conductivity and viscosity aspects are also considered. The complicated nonlinear problem is treated numerically by using Finite difference method. Optimization procedure implemented via Response surface Methodology for the effective parameters thermophoresis parameter, Hartmann number and radiation parameter on the heat transfer rate. The axial velocity is a dwelling function of the inclined angle of the magnetic field, and the variable viscosity parameter. The temperature profile hikes with an exponential space-related heat source and thermal radiation aspects. Also, the heat transport rate is highly sensitive towards nonlinear thermal radiation parameter compared to the thermophoresis effect and Hartmann number

    Hall effect on two-phase radiated flow of magneto-dusty-nanoliquid with irregular heat generation/consumption

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    Impacts of Hall current and irregular heat generation/consumption on two-phase flow of dusty-nanofluid are scrutinized. Particulate nanofluid saturates the stretched surface. Heat transfer mechanism is studied via radiative heating and viscous dissipation aspects. The nanoliquid is a carrier fluid and dust (micro-sized fine particles) particles are suspended in it. Governed equations are remodeled in the form of ordinary differential system using stretching transformations. Numeric solutions are developed via Runge-Kutta-Fehlberg scheme. The influence of pertinent parameters on both nanofluid and particle phase flow fields are studied through graphs. The friction factor and Nusselt number are also studied. It is established that the Hall current has a significant impact on thermal flow fields. The irregular heat generation/consumption aspect is constructive for the heating process. AMS Subject Classification (2000): 76T15, 80A20, Keywords: Dusty nanofluid, Irregular heat generation, consumption, Hall current, Mixed convectio

    Cattaneo-Christov heat flux on UCM nanofluid flow across a melting surface with double stratification and exponential space dependent internal heat source

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    Melting and exponential space dependent internal heat source effects on magnetohydrodynamic of upper convected Maxwell liquid towards a horizontal flat surface are addressed. The combined effect of Brownian motion and thermophoresis in nanofluid modeling are retained. The Cattaneo-Christov heat flux model is imposed. Impacts of thermal and solutal stratifications are also accounted. A set of similarity variables are utilized to form ordinary differential system from the prevailing partial differential equations. The problem of ordinary differential system is analyzed numerically through Runge-Kutta-Fehlberg based shooting method. Graphical results of pertinent parameters on the velocity, temperature and nanoparticle concentration are studied. Skin friction coefficient, local Nusselt number and Sherwood number are also addressed
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