Presence Of Convective Boundary Conditions Research Articles

Numerical simulation of time-dependent viscous fluid flow with upward and downward fluctuation of spinning disk

The parametric approach towards time-dependent viscous fluid flow across a gyrating disk with upward and downward fluctuation. The major goal of this research is to assess fluid flow under the influence of magnetic fields and heat propagation processes. Because they provide a thorough description of electromagnetic interactions. Maxwell's equations are at the heart of all contemporary information and communication technologies. The governing equations comprising Navier Stokes equation, energy, concentration, and Maxwell equations have been represented appropriately for this purpose. The governing equations are turned down to the system of non-linear ODEs through a resemblance framework. The obtained system of differential equations has been resolved via numerical procedure Parametric Continuation Method (PCM). For the scale reliability purpose, the outcomes are compared to another numerical Matlab scheme boundary value solver. In the current analysis, the presence of convective boundary conditions correlated to mass and energy is of physical relevance. The numerical findings are provided in tabular and graphical forms. The consequences of suction and wall injection have been also highlighted. The upward motion of the spinning disc is thought to lead to comparable findings as in an injection scenario, whilst the downhill motion is thought to contribute to wall suction-like effects.

Analytical solutions of triple‐diffusive magnetohydrodynamic fluid flowing through a stretching/shrinking sheet

AbstractThe aim of this article is to investigate the dual nature solutions of the triple diffusive magnetohydrodynamic flow due to stretching/shrinking surfaces. The system of nonlinear partial differential equations is transformed into nonlinear ordinary differential equations with the help of compatible transforms. Analytical dual solutions are obtained for every unknown velocity, temperature, and concentration profile in terms of known physical parameters. Heat and mass transfer analyses have been carried out in the presence of convective boundary conditions. The graphic interpretation of the possible dual solutions of dimensionless velocity, temperature, concentration, skin‐friction coefficient, and Nusselt and Sherwood numbers is analyzed under the influence of different known physical parameters. The obtained results are validated against previously published results for a special case of the problem.

Activation of energy in MHD Casson nanofluid flow through a porous medium in the presence of convective boundary conditions and suction/injection

Casson fluids are used to understand the rheological characteristics of pigment-oil suspensions, polymeric gels, emulsions, heavy oil, etc. Hence in this article, numerical work is carried out to investigate a steady MHD flow of a Casson nanofluid with the Cattaneo-Christov model over a stretching sheet in the presence of a porous medium with heat generation, and suction/injection. The effects of activation energy and chemical reactions are also considered. The concept of MHD is significant because of its numerous applications, including power generators, cooling process, sensors, and magnetic drug targeting. The governing equations of the model are reduced to a system of nonlinear coupled ordinary differential equations by appropriate transformations and are solved numerically via the bvp5c MATLAB package. The effects of the pertinent parameters on the velocity, temperature, and fluid concentration fields along with the skin friction, heat, and mass transfer rates are discussed in detail through figures and tables. It is reported that the velocity field decreases with an escalation in the magnetic field, porosity, and suction. However, the heat transfer rate enhances due an enhancement in suction and the Biot number, whereas it declines with the increasing values of the Brownian motion, thermophoresis, heat generation and thermal relaxation parameters. Furthermore, activation energy increases the fluid concentration.

Oscillatory and transient role of heat transfer and magnetic flux around magnetic-driven stretching cylinder under convective boundary conditions

The magnetic outcomes are frequently implemented for assessing fluid specifications around stretching magnetized surfaces and energy producing technology of thermodynamics. Magnetohydrodynamic reactors and magneto-hydrodynamic generators are two primary methods for producing magnetic flux through ionized fluids along a warmed and magnetized stretched surface. The desired outcomes of the current work are to investigate magnetic flux and heat transmission in the presence of convective boundary conditions using an electrically-conducting fluid over a stretchable cylinder. Most of the parameters are considered in the discussion with intensity and variance due to time dependent methodology. The suggested fluctuating dynamic computational framework is formulated for associated forms of coupled model under boundary variables. The appropriate non-dimensional variables are used to transform the complicated mathematical expression into a non-dimensional representation. To make the non-dimensional representation easier to work for efficient statistical calculations, it is reduced further. Later, for a variety of variables, significant computations are performed via the implicit finite difference methodology. The main finding of current communication is to explore the prominent slip effect in temperatures for every Biot number around all positions. From a physical standpoint, the phenomenon was predictable since surface heat flux is employed as sporting source to increase heat transmission in electric-conducting fluids. For every possible angle, the field of magnetism increases with minimal intensity of surface heat flux. Since, magnetizing functions referred to as an insulating layer that diminishes high temperatures across surfaces and fluids.

Buoyancy flow of nanohybrid fluid over a rotating sphere imperiled to convective and viscous heating

The thermal radiation and convective condition principles were working on specific functions like gas turbines, electrical fuel, renewable energy, projectiles, nuclear power plants, aerospace engineering, and thermal transportation. Considering the aforementioned functions, the present analysis inspected the stagnation point hybrid nanofluids movement over the rotating sphere on the behavior of viscous dissipation and thermal radiation. Silver and Ferrous nanoparticles including the host fluid water were held into affected the flow. The presence of convective boundary conditions is incorporated within the system. Applying appropriate correspondence factors, nonlinear governing equations were transformed with ordinary differential equations. This finite element method is applied to find the mathematical solutions to the boundary conditions and simplified equations. These outcomes convey to temperature was decreased about accelerated factor, although primary velocity was found into increased. The heat transfer was magnified by thermal Biot number, and that rate of development was greater about hybrid nanosuspension. The heat transport method was reduced by the Eckert number; also that reduction rate was similarly dull on hybrid.

MHD radiative flow of Williamson nanofluid along stretching sheet in a porous medium with convective boundary conditions

Fluid heating and cooling is significant in a variety of industries, including power generation and transportation. Improvements in the thermal conductivity of the base fluid can also help in heat transmission. For this purpose, the effects of magneto hydrodynamics (MHD) and thermal radiation on mixed convection flow of Williamson nanofluid across a stretched sheet embedded in a porous medium in the presence of slip and convective boundary conditions is investigated. The Boungiorno model is adopted to analyze the impact of various dimensionless parameters on velocity, temperature, and nanoparticle concentration in the presence of slip and convective boundary conditions. The nonlinear governing equations are non-dimensionalized using similarity transformations, and the Keller box technique is utilized to solve them numerically. The current code is validated by generating numerical results for wall shear stress and compared them to previously published results. The comparison demonstrates that the outcomes are extremely similar. The results reveal that in the presence of a porous media, raising the magnetic and slip parameters reduced the nanofluid's velocity. It is also noticed that by increasing the radiation parameter, the heat and mass transfer rates on the surface of the stretching sheet are improved. In the presence of convective boundary conditions, the effect of Brownian motion and thermophoresis parameters on nanoparticle concentration was observed to be more profound.

Finite element analysis of micropolar nanofluid flow through an inclined microchannel with thermal radiation

PurposeIn recent years, microfluidics has turned into a very important region of research because of its wide range of applications such as microheat exchanger, micromixers fuel cells, cooling systems for microelectronic devices, micropumps and microturbines. Therefore, in this paper, micropolar nanofluid flow through an inclined microchannel is numerically investigated in the presence of convective boundary conditions. Heat transport of fluid includes radiative heat, viscous and Joule heating phenomena.Design/methodology/approachGoverning equations are nondimensionalized by using suitable dimensionless variables. The relevant dimensionless ordinary differential systems are solved by using variational finite element method. Detailed computations are done for velocity, microrotation and temperature functions. The influence of various parameters on entropy generation and the Bejan number is displayed and discussed.FindingsIt is established that the entropy generation rate increased with both Grashof number and Eckert number, while it decreased with nanoparticle volume fraction and material parameter. Temperature is decreased by increasing the volume fraction of Ag nanoparticle dispersed in water.Originality/valueAccording to the literature survey and the best of the author’s knowledge, no similar studies have been executed on micropolar nanofluid flow through an inclined microchannel with effect of viscous dissipation, Joule heating and thermal radiation.

Micropolar flow of EMHD nanofluid with nonlinear thermal radiation and slip effects

Magneto-micropolar electrically conducting nanofluid flow over a linearly stretching sheet for heat and mass transfer in the presence of convective boundary condition is considered. In the energy equation, non-linear thermal radiation and Joule heating effects are incorporated. Velocity slip condition at the solid liquid interface is also employed. In the current model viscous dissipation and mixed convection aspects are also taken into account. Non dimensional ordinary differential equations are acquired by implementing the similar transformations on the governed partial differential equations. The shooting technique is utilized along with Runga-Kutta integration scheme to tackled the differential equations numerically. All the numerical calculations are further verified with MATLAB bvp4c scheme. Graphical results are exploited to view the behavior of emerging parameters on velocity, temperature and concentration of nanofluid. In limiting case, MATLAB code is verified with a published article and a good agreement is noted. Numerical computations are performed for the local Sherwood and Nusselt number and skin friction coefficients. It is observed that the electric field is dominant over the magnetic field. The behavior of velocity profile is reserved in the absence of the electric field. Further, the nonlinear thermal radiation aggregates the temperature profile.

Performance of heat transfer in MHD mixed convection flow using nanofluids in the presence of viscous dissipation: Local non-similarity solution

In this study, an investigation has been carried out to examine the effects of thermal radiation, heat generation/absorption, viscous dissipation and suction parameter on MHD flow of water-base nanofluid (Ag, Cu, Al2O3, CuO and TiO2). This study also focused on the mixed convective flow of water-base nanofluid due to a vertical permeable plate in the presence of convective boundary condition. Further, heat transfer has been inspected for water-base fluid influenced by heat generation/absorption and viscous dissipation. Moreover, the governing equations are reduced to nonlinear ordinary differential equations via Sparrow–Quack–Boerner local non-similarity method. These nonlinear ODEs are simulated numerically by means of Runge–Kutta–Fehlberg method (RKF-45). The impact of pertinent parameters on the dimensionless velocity, nanofluid temperature, skin friction and local Nusselt number are discussed and displayed. The results match with a special case of formerly available work. The present exploration exhibits that nanoparticle volume fraction increases the velocity and temperature of Cu-water nanofluid. It is also shown that magnetic parameter reduces the heat transfer rate.

Nonlinear Electro-Thermal Monte Carlo Device Simulation

Abstract A model of self-heating is incorporated into a cellular Monte Carlo (CMC) particle device simulator. This is done through the solution of an energy balance equation (EBE) for phonons, which self-consistently couples charge and heat transport in the simulation. First, several tests are performed to verify the applicability and accuracy of the proposed nonlinear iterative solver in the presence of convective boundary conditions, as compared to a finite element analysis (FEA) solver as well as using the Kirchhoff Transformation. Finally, a fully coupled electro-thermal characterization of a GaN/AlGaN high electron mobility transistor (HEMT) is performed, and the effects of nonideal interfaces and boundary conditions are studied.

Eyring–Powel fluid flow past a power-law stretching permeable sheet in a free stream moving with power-law velocity in the presence of convective boundary condition

This paper intends to discuss the flow of a non-Newtonian fluid complying with the Erying–Powell fluid model towards a power-law extended sheet in a free stream moving with power-law velocity with the occurrence of suction/blowing and the convective boundary condition. By means of similarity transformations, the leading partial differential equations are reduced to ordinary differential equations which are nonlinear. Numerical solutions of these equations are then acquired utilising the Runge–Kutta method with a combination of the shooting technique. It is observed that velocity drops off, but the temperature augments with the growing values of one of the material parameters of the fluid. Reverse trends for velocity and temperature are noted for other material parameters.

Numerical study of magnetohydrodynamics and thermal radiation on Williamson nanofluid flow over a stretching cylinder with variable thermal conductivity

The effect of nanofluid and thermal radiation on MHD Williamson fluid over a stretching cylinder in the presence of convective boundary conditions is analyzed. The variable thermal conductivity is considered during the formulation of energy equation. Nonlinear ordinary differential equations are attained by proposing relevant similarity transformations on partial differential equations. These non-dimensional ordinary differential equations are then converted to the system of first order ODEs and solved numerically by shooting method. Results are further compared by using bvp4c, a MATLAB built-in function. The results obtained from MATLAB codes are compared with previously published results of the same nature in limiting case. Numerical results of skin-friction coefficient, local Nusselt and Sherwood numbers are systematized in the form of tables. The effect of prominent parameters on velocity, temperature and concentration is displayed by using graphs. It is observed that velocity profile diminishes for the higher values of Weissenberg number but a reverse relation is noticed for the temperature profile.

Numerical Investigation of Two-Phase Mixed Convection Flow of Particulate Oldroyd-B Fluid with Non-Linear Thermal Radiation and Convective Boundary Condition

The present investigation addresses the mixed convection two-phase flow of dusty Oldroyd-B fluid towards a vertical stretching surface in the presence of convective boundary condition and nonlinear thermal radiation. The fluid and dust particles motion is coupled only in the course of drag and heat transfer between them. The Stokes linear drag theory is employed to model the drag force. The numerical solutions based on the Runge-Kutta-Fehlberg 45 scheme with shooting method are presented for both fluid and particle phase velocity and temperature fields. Further, numerical results are obtained for skin friction factor and local Nusselt number of prescribed values of pertinent parameters. The results are presented graphically and the physical aspects of the problem are analyzed. The obtained results are validated with existing results and found to be in good agreement. It is found that the mass concentration of the dust particle parameter plays a key role in controlling flow and thermal behaviour of non-Newtonian fluids.

A numerical treatment of MHD radiative flow of Micropolar nanofluid with homogeneous-heterogeneous reactions past a nonlinear stretched surface

The impact of nonlinear thermal radiation in the flow of micropolar nanofluid past a nonlinear vertically stretching surface is investigated. The electrically conducting fluid is under the influence of magnetohydrodynamics, heat generation/absorption and mixed convection in the presence of convective boundary condition. The system of differential equations is solved numerically using the bvp4c function of MATLAB. To authenticate our results, two comparisons with already studied problems are also conducted and an excellent concurrence is found; hence reliable results are being presented. Complete deliberation for magnetite nanofluid with Ferric Oxide (Fe3O4) nanoparticles in the water-based micropolar nanofluid is also given to depict some stimulating phenomena. The effect of assorted parameters on velocity, homogeneous-heterogeneous reactions, temperature and micropolar velocity profiles are discussed and examined graphically. Moreover, graphical illustrations for the Nusselt number and Skin friction are given for sundry flow parameters. It is examined that temperature distribution and its associated boundary layer thickness increase for mounting values of the magnetic parameter. Additionally, it is detected that the Nusselt number decays when we increase the values of the Biot number.

MHD natural convection of ferrofluid from a fixed vertical plate with aligned, transverse magnetic field and convective boundary condition

The present study analyzed the influence of aligned and transverse magnetic field on two dimensional natural convection boundary layer flow of a ferrofluid over a semi-infinte fixed vertical plate in the presence of convective boundary condition. It is assumed that the left surface of the plate is in contact with a hot fluid while the cold fluid on the right surface. Two different base fluids (water and kerosene) containing magnetite (Fe3O4) as ferroparticle are considered. The governing boundary layer equations along with the appropriate boundary conditions are transformed to a set of ordinary differential equations using similarity variables. The resultant system of equations is then solved numerically by using Keller-Box method. Numerical results for the skin friction coefficient and local Nusselt number were presented whilst the velocity and temperature profiles illustrated graphically and analyzed. The effect of the inclined angle, magnetic field parameter, volume fraction, Grashof number and Biot number on the flow field were discussed. It is found that the heat transfer rate at the plate surface with Fe3O4- kerosene ferrofluid is higher than Fe3O4- water.

Closed form dual nature solutions of fluid flow and heat transfer over a stretching/shrinking sheet in a porous medium

The aim of this work is to investigate the dual nature solutions of the fluid flow due to stretching/shrinking permeable surface saturated in a porous medium. Heat transfer analysis has been carried out in the presence of convective boundary conditions. Compatible transform are utilized to rehabilitate the system of nonlinear partial differential equations into the nonlinear ordinary differential equations. Closed form dual solutions are obtained for each unknown velocity and temperature profiles in terms of Gamma functions. Graphical interpretation of the possible dual solutions of dimensionless velocity, temperature, skin-friction coefficient, local Nusselt number as well as for stream lines and isotherms are analyzed under the influence of different physical parameters. It is finally concluded that all the obtained results against each velocity profile depicts the both increasing and decreasing behavior according the upper and lower solution. However, temperature profile shows the same behavior of two different solutions for each parameter. Isotherms behavior in the entire domain of the model shows the significant variation for three different fluids (air, water and kerosene oil).

Note on effect of joule heating and MHD in the presence of convective boundary condition for upper-convected Maxwell fluid through wall jet

Abstract In this communication some inconsistencies associated with the derivation of the governing flow equation and choice of space dependent applied magnetic field are pointed out in a recent study by Zaidi and Mohyud-Din [1]. The detail derivation of the Lorentz force term appearing in the governing flow equation is presented. Furthermore, it is explicitly shown that Maxwell's equations are violated for the considered space dependent magnetic field. Therefore, all subsequent analysis needs corrections.

On unsteady Falkner-Skan flow of MHD Carreau nanofluid past a static/moving wedge with convective surface condition

Abstract The aim of this article is to present the locally similar solutions for the unsteady two-dimensional Falkner-Skan flow of MHD Carreau nanofluid past a static/moving wedge in the presence of convective boundary condition. The effects of Brownian motion and thermophoresis are taken into account. The local similarity transformations are utilized to alter the leading time dependent non-linear partial differential equations to a set of ordinary differential equations. The obtained non-linear ordinary differential equations are solved numerically by the two different numerical techniques namely shooting method with Felhberg formula and Newton's Raphson as well as bvp4c function in MATLAB to explore the impacts of pertinent parameters. A comparison is presented between the current study and published works and found to be in outstanding agreement. It is important to mention that an increment in the wedge angle parameter depreciate the heat and mass transfer rate both for shear thinning and shear thickening fluids. Furthermore, the thermal boundary layer thickness is an increasing function of the generalized Biot number in shear thinning and shear thickening fluids. Additionally, temperature is enhanced by growing the Brownian motion and the thermophoresis parameters.

Slip flow and nonlinear radiative heat transfer of suspended nanoparticles due to a rotating disk in the presence of convective boundary condition

The slip flow and nonlinear radiative heat transfer of suspended nanoparticles due to a rotating disk is analysed in the present work. Two types of nanoparticles namely copper and aluminium oxide and water is treated as base fluid. Suitable similarity transformations are used to reduce the nonlinear partial differential equations to ordinary differential equations. Flow and heat transfer characteristics are computed by numerical technique Runge-Kutta-Fehlberg-fourth and fifth order method. Further, the skin friction coefficient and Nusselt number are presented and examined for pertinent parameters. It is noticed that the higher velocity slip parameter decreases the radial and azimuthal velocities. Also, the rate of heat transfer enhances when the nanoparticle volume fraction increases.

Slip flow and nonlinear radiative heat transfer of suspended nanoparticles due to a rotating disk in the presence of convective boundary condition

Slip flow and nonlinear radiative heat transfer of suspended nanoparticles due to a rotating disk in the presence of convective boundary condition