Thermal Slip Effects Research Articles

Thermal radiation and slip effects on MHD stagnation point flow of non-Newtonian nanofluid over a convective stretching surface

The present analysis examines the combine effects of thermal radiation and velocity slip along a convectively nonlinear stretching surface. Moreover, MHD effects are also considered near the stagnation point flow of Casson nanofluid. Slipped effects are considered with the porous medium to reduce the drag reduction at the surface of the sheet. Main structure of the system is based upon the system of partial differential equations attained in the form of momentum, energy, and concentration equations. To determine the similar solution system of PDEs is rehabilitated into the set of nonlinear ordinary differential equations (ODEs) by employing compatible similarity transformation. Important physical parameters are acquired through obtained differential equations. To determine the influence of emerging parameters, resulting set of ODE’s in term of unknown function of velocity, temperature, and concentration are successfully solved via Keller’s box-scheme. All the obtained unknown functions are discussed in detail after plotting the results against each physical parameter. To analyze the behavior at the surface: skin friction, local Nusselt and Sherwood numbers are also illustrated against the velocity ratio parameter A, Brownian motion Nb, thermophoresis Nt, and thermal radiation parameters R. Results obtained from the set of equations described that skin friction is decreasing function of A, and local Nusselt and Sherwood number demonstrate the significant influenced by Brownian motion Nb, thermophoresis Nt, and radiation parameters R.

Impinging of metallic nanoparticles along with the slip effects through a porous medium with MHD

The considered analysis comprises the effects of nanoparticles on the characteristics of the peristaltic flow through a homogeneous porous medium under the impact of magnetic field and slip effects by considering an appropriate mathematical model. Analysis is introduced by considering blood as the base fluid and metals such as copper and silver as the nanoparticles in the existence of the thermal and velocity slip effects. Lubrication approach is used to simplify the problem. Impact of related parameters on temperature, pressure rise, pressure gradient, velocity and streamlines are interpreted graphically. Comparison of the pure blood, silver blood and copper blood is presented and analyzed. It is also revealed that inclusion of nanoparticles scales down the velocity and temperature of fluid. Another valuable finding of the present investigation is that the silver nanoparticles enhance the pressure gradient when compared with the copper nanoparticles. Therefore, the current investigation is capable to achieve some essential and interesting characteristics in few biomedical applications.

Velocity and thermal slip effects on MHD third order blood flow in an irregular channel though a porous medium with homogeneous/ heterogeneous reactions

AbstractThis communication presents the transportation of third order hydromagnetic fluid with thermal radiation by peristalsis through an irregular channel configuration filled a porous medium under the low Reynolds number and large wavelength approximations. Joule heating, Hall current and homogeneous-heterogeneous reactions effects are considered in the energy and species equations. The Second-order velocity and energy slip restrictions are invoked. Final dimensionless governing transport equations along the boundary restrictions are resolved numerically with the help of NDsolve in Mathematica package. Impact of involved sundry parameters on the non-dimensional axial velocity, fluid temperature and concentration characteristics have been analyzed via plots and tables. It is manifest that an increasing porosity parameter leads to maximum velocity in the core part of the channel. Fluid velocity boosts near the walls of the channel where as the reverse effect in the central part of the channel for higher values of first order slip. Larger values of thermal radiation parameter

Influence of Brownian Motion and Thermal Radiation on Heat Transfer of a Nanofluid Over Stretching Sheet with Slip Velocity

In this study combined effect of thermal radiation and velocity slip in the boundary layer flow and heat transfer over a stretching surface with Brownian motion is considered. The similarity transformation and Runge–Kutta–Fehlberg method with shooting technique is used to solved the set of nonlinear ordinary differential equations. The influence of important physical parameters such as Prandtl number, slip factor, Brownian motion, Lewis number and thermophoretic parameters are analyzed on the velocity, temperature, surface shear stress, Nusselt number and Sherwood number. The results show that the effect of increase in the internal heat source/sink parameter increases the temperature in the thermal boundary layer. Further, local Nusselt number decreases with an increase in the value of the thermophoretic parameter, Brownian motion parameter and internal heat source/sink parameter. Also, it can be concluded that the effect of slip velocity is to decrease the shear stress at the surface of the stretching sheet.

Peristaltic flow of rotating couple stress fluid in a non-uniform channel

An analysis has been carried out for thermal radiation effects on peristaltic activity of couple stress fluid in a non-uniform rotating channel. The velocity and thermal slip effects at the channel boundaries are considered. Heat transfer with non-uniform heat generation/absorption effect is also taken into consideration. System of ordinary differential equations is obtained from the governing nonlinear partial differential equations. Small Reynolds number and large wavelength approximations are employed. Numerical technique is applied to solve the non-linear system. The influences of the various fluid and geometric parameters on velocities and temperature profiles have been presented and analyzed.

Unsteady flow and heat transfer of UCM fluid in a porous channel with variable thermal conductivity and ion slip effects

Unsteady flow and heat transfer of UCM fluid in a porous channel with variable thermal conductivity and ion slip effects

Thermally developing MHD peristaltic transport of nanofluids with velocity and thermal slip effects

We investigate the velocity slip and thermal slip effects on peristaltically driven thermal transport of nanofluids through the vertical parallel plates under the influence of transverse magnetic field. The wall surface is propagating with sinusoidal wave velocity c. The flow characteristics are governed by the mass, momentum and energy conservation principle. Low Reynolds number and large wavelength approximations are taken into consideration to simplify the non-linear terms. Analytical solutions for axial velocity, temperature field, pressure gradient and stream function are obtained under certain physical boundary conditions. Two types of nanoparticles, SiO2 and Ag, are considered for analysis with water as base fluid. This is the first article in the literature that discusses the SiO2 and Ag nanoparticles for a peristaltic flow with variable viscosity. The effects of physical parameters on velocity, temperature, pressure and trapping are discussed. A comparative study of SiO2 nanofluid, Ag nanofluid and pure water is also presented. This model is applicable in biomedical engineering to make thermal peristaltic pumps and other pumping devices like syringe pumps, etc. It is observed that pressure for pure water is maximum and pressure for Ag nanofluid is minimum.

Influence of variable viscosity and radial magnetic field on peristalsis of copper-water nanomaterial in a non-uniform porous medium

Paramount idea of this article is to model peristaltic flow of copper-water for spherical and cylindrical shape magneto-nanoparticles in a curved channel. The nanomaterial saturates a non-uniform permeable medium in which the porosity of the medium fluctuate with the distance from the channel boundaries. H–C model is considered to predict the effective thermal conductivity of the nanomaterial. Effects of radial magnetic field, variable viscosity and mixed convection are also accounted. The boundary conditions yield the second order velocity and thermal slip effects. Assumptions of small Reynolds number and large wavelength approximation are utilized to simplify the governing equations. Final form of the system of equations are solved numerically through NDSolved command in Mathematica 8 software. Influence of embedded parameters on velocity, temperature and heat transfer rate of the nanomaterial at upper wall of the channel are physically interpreted. Comparison between the spherical and cylindrical shapes magneto-nanoparticles is also presented. Graphical results shows that pressure gradient and pressure rise are enhanced for both radial magnetic field parameter and nanoparticle volume fraction. Velocity of the nanomaterial increases when variable viscosity parameter is enhanced.

Velocity, thermal and concentration slip effects on a magneto-hydrodynamic nanofluid flow

This article examines the magneto-hydrodynamic (MHD) flow of nanofluid bounded by a stretching surface. The slip conditions are utilized in the present analysis. The involved differential systems are solved for the velocity, temperature and mass fraction. Graphical and numerical results are reported for the analysis of various parameters of interest entering into the modeled problems. Combined effects of thermal and concentration jump are analyzed. Various tables are constructed to show the rheological effects of different physical parameters. Streamlines are plotted showing the rheology for the slip and no slip flow regime. Plots of skin friction are also prepared for the slip and magnetic field effects.

Non-Linear Thermal Radiation and Slip Effect on Boundary Layer Flow and Heat Transfer of Suspended Nanoparticles Over a Stretching Sheet Embedded in Porous Medium with Convective Boundary Conditions

Non-Linear Thermal Radiation and Slip Effect on Boundary Layer Flow and Heat Transfer of Suspended Nanoparticles Over a Stretching Sheet Embedded in Porous Medium with Convective Boundary Conditions

MHD dissipative flow and heat transfer of Casson fluids due to metachronal wave propulsion of beating cilia with thermal and velocity slip effects under an oblique magnetic field

A theoretical investigation of magnetohydrodynamic (MHD) flow and heat transfer of electrically-conducting viscoplastic fluids through a channel is conducted. The robust Casson model is implemented to simulate viscoplastic behavior of fluids. The external magnetic field is oblique to the fluid flow direction. Viscous dissipation effects are included. The flow is controlled by the metachronal wave propagation generated by cilia beating on the inner walls of the channel. The mathematical formulation is based on deformation in longitudinal and transverse velocity components induced by the ciliary beating phenomenon with cilia assumed to follow elliptic trajectories. The model also features velocity and thermal slip boundary conditions. Closed-form solutions to the non-dimensional boundary value problem are obtained under physiological limitations of low Reynolds number and large wavelength. The influence of key hydrodynamic and thermo-physical parameters i.e. Hartmann (magnetic) number, Casson (viscoplastic) fluid parameter, thermal slip parameter and velocity slip parameter on flow characteristics are investigated. A comparative study is also made with Newtonian fluids (corresponding to massive values of plastic viscosity). Stream lines are plotted to visualize trapping phenomenon. The computations reveal that velocity increases with increasing the magnitude of Hartmann number near the channel walls whereas in the core flow region (center of the channel) significant deceleration is observed. Temperature is elevated with greater Casson parameter, Hartmann number, velocity slip, eccentricity parameter, thermal slip and also Brinkmann (dissipation) number. Furthermore greater Casson parameter is found to elevate the quantity and size of the trapped bolus. In the pumping region, the pressure rise is reduced with greater Hartmann number, velocity slip, and wave number whereas it is enhanced with greater cilia length.

Hydromagnetic peristaltic transport of copper–water nanofluid with temperature-dependent effective viscosity

The unique chemical, mechanical, and thermodynamic properties of nanofluids make them a subject of great interest for scientists from all domains. Such fluids are of particular significance in biomedical engineering owing to their vast and novel applications in modern drug delivery systems; for example, mixed convective peristaltic flow of water-based nanofluids under the influence of an externally applied magnetic field is of particular significance. Hence, a lot of research has focused on peristalsis in the presence of velocity and thermal slip effects. An empirical relation for the effective viscosity of the nanofluid is proposed here for the first time. The viscosity of the nanofluid varies with temperature and nanoparticle volume fraction. Numerical simulation of the resulting nonlinear system of equations is presented for different quantities of interest. The results indicate that the maximum velocity and temperature of the copper–water nanofluid increase for larger variable viscosity parameter. The pressure gradient in the wider part of the channel is also found to increase as a function of the variable viscosity parameter. The variable viscosity parameter also influences the size of the trapped bolus. An increase in the nanoparticle volume fraction reduces the reflux phenomenon in a peristaltic flow.

Dual solutions for radiative MHD forced convective flow of a nanofluid over a slendering stretching sheet in porous medium

In this study we analyzed the magnetohydrodynamic forced convective flow of a nanofluid over a slendering stretching sheet in porous medium in presence of thermal radiation and slip effects. We presented dual solutions for no-slip and Navier slip conditions. Using self similarity transformation, the governing partial differential equations are transformed into nonlinear ordinary differential equations and solved numerically using bvp5c Matlab package. The effects of dimensionless governing parameters on velocity and temperature profiles of the flow are discussed with the help of graphs. Numerical computations are carried out and discussed for skin friction coefficient and local Nusselt number. We found an excellent agreement of the present results with the existed results under some special conditions. Results indicate that the dual solutions exist only for certain range of velocity slip parameter. It is also found that the heat transfer performance is high in presence of velocity slip effect.

Theoretical examination of nanoparticles as a drug carrier with slip effects on the wall of stenosed arteries

The present examination deals with the effects of nanoparticles on the characteristics of the blood flow through bell shaped stenosed arteries by using a suitable mathematical model. Investigation is carried out using copper and silver nanoparticles as a drug carrier in the presence of the velocity and thermal slip effects. The governing equations are considered for viscous nature of blood model and then solved by using mild stenosis approximations to calculate the hemodynamic effect of stenosis. It is observed that addition of nanoparticles reduces the resistance impedance to blood flow. Another important finding of the considered analysis is that the drug silver nanoparticles show good agreement to reduce resistance impedance to blood flow when compare to the copper nanoparticles. Therefore, the present analysis is able to conclude some important features of interest in some biomedical applications.

Analysis of fluid motion and heat transport on magnetohydrodynamic boundary layer past a vertical power law stretching sheet with hydrodynamic and thermal slip effects

The present model is committed to the study of MHD boundary layer flow and heat transfer past a nonlinear vertically stretching porous stretching sheet with the effects of hydrodynamic and thermal slip. The boundary value problem, consisting of boundary layer equations of motion and heat transfer, which are nonlinear partial differential equations are transformed into nonlinear ordinary differential equations, with the aid of similarity transformation. This problem has been solved, using Runge Kutta fourth order method with shooting technique. The effects of various physical parameters, such as, stretching parameter m, magnetic parameter M, porosity parameter fw, buoyancy parameter λ, Prandtl number Pr, Eckert number Ec, hydrodynamic slip parameter γ, and thermal slip parameter δ, on flow and heat transfer characteristics, are computed and represented graphically.

MHD mixed convection nanofluid flow and heat transfer over an inclined cylinder due to velocity and thermal slip effects: Buongiorno's model

The present study deals with numerical investigation of mixed convection slip flow and heat transfer of uniformly conducting nanofluid past an inclined cylinder under the influence of Brownian motion, thermophoresis and viscous dissipation. The governing partial differential equations in cylindrical form are reduced into set of nonlinear ordinary differential equations by using appropriate similarity transformation and solved numerically by the fourth order Runge–Kutta–Fehlberg method with shooting technique. The physical characteristics namely skin friction, heat transfer, temperature and velocity are discussed with the variation of governing parameters and presented graphically in this paper. The study shows the critical range of mixed convection parameter or Richardson number Ri, curvature parameter γ, mass transfer parameter s and stretching/shrinking parameter χ, for the existence of multiple branches of the solution. Skin friction increases with buoyancy parameter while heat transfer decreases. The rate of heat transfer enhances with mass transfer parameter but decreases with thermal slip parameter. The present problem has many applications in food processing specially drying of cylinder-shaped bodies which takes shrinkage into account at different air drying temperatures.

Unsteady MHD Stagnation‐Point Flow Toward a Shrinking Sheet with Thermal Radiation and Slip Effects

The problem of an unsteady magnetohydrodynamic stagnation point flow of an incompressible viscous fluid over a shrinking sheet is discussed in the presence of thermal radiation and boundary slip, which has not been documented to date in the literature. The governing boundary‐layer equations are transformed to high order nonlinear and ordinary differential equations by similarity transformations and then solved numerically. The effects of magnetic parameter, unsteadiness parameter, radiation parameter, velocity, and thermal slip parameters on velocity and temperature are analyzed and discussed. It is found that dual solutions of both velocity and temperature fields exist for negative values of the velocity ratio parameter. The results indicate that dual solution domains of velocity and temperature expand as the unsteadiness parameter increases.

Influence of thermal and velocity slip on the peristaltic flow of Cu–water nanofluid with magnetic field

The peristaltic flow of an incompressible viscous fluid containing copper nanoparticles in an asymmetric channel is discussed with thermal and velocity slip effects. The copper nanoparticles for the peristaltic flow water as base fluid is not explored so far. The equations for the purposed fluid model are developed first time in literature and simplified using long wavelength and low Reynolds number assumptions. Exact solutions have been calculated for velocity, pressure gradient, the solid volume fraction of the nanoparticles and temperature profile. The influence of various flow parameters on the flow and heat transfer characteristics is obtained.

Peristalsis of silver-water nanofluid in the presence of Hall and Ohmic heating effects: Applications in drug delivery

This study examines the peristaltic transport of silver-water nanofluid in the presence of constant applied magnetic field. Ohmic heating and Hall effects are also taken into account. Present attempt includes the velocity and thermal slip effects. Mathematical modeling is carried out employing the lubrication approach. The resulting system of equations is numerically solved. Effects of sundry parameters on the quantities of interest are studied through graphs. Results show that addition of 5% silver nanoparticles reduces the velocity of base fluid (water in this case) by almost 10% and its temperature by 16%. Further presence of Hall effects lessens the changes brought by an applied magnetic field in the state of nanofluid. Maximum velocity of nanofluid decreases with an increase in the value of velocity slip parameter whereas maximum temperature enhances by increasing the thermal slip parameter. It is hoped that the presented analysis is of considerable importance in the modern drug delivery systems in biomedical engineering.

Thermal radiation and slip effects on MHD stagnation point flow of nanofluid over a stretching sheet

Present model is devoted for the stagnation point flow of nanofluid with magneto-hydrodynamics (MHD) and thermal radiation effects passed over a stretching sheet. Moreover, we have considered the combined effects of velocity and thermal slip. Condition of zero normal flux of nanoparticles at the wall for the stretched flow phenomena is yet to be explored in the literature. Convinced partial differential equations of the model are transformed into the system of coupled nonlinear differential equations and then solved numerically. Graphical results are plotted for velocity, temperature and nanoparticle concentration for various values of emerging parameters. Variation of stream lines, skin friction coefficient, local Nusselt and Sherwood number are displayed along with the effective parameters. Final conclusion has been drawn on the basis of both numerical and graphs results.