Slip Conditions Research Articles

Influence of Joule heating and slip on 3D MHD rotating nanoliquid flow with radiation, viscous dissipation, Soret and Dufour effects

Purpose The purpose of this study is to explore the impact of Joule heating, slip conditions, Dufour and Soret effects on three-dimensional magneto-convection of nanoliquid over a rotating surface in the existence of thermal radiation, viscous dissipation and internal heat generation/absorption. Design/methodology/approach The considered physical system is modelled by a set of partial differential equations (PDEs) with conditions at surface. Then, the nonlinear PDEs are altered into a system of ordinary differential equations and they are solved numerically by the Runge−Kutta−Fehlberg method. Plotting the collected velocity, temperature and solute concentration characteristics allows one to see how relevant parameters affect the results. Calculations are made for skin friction and the rate of heat and mass transfer. Findings The outcomes are portrayed in the form of tables and graphs with a wide range of parameter involved in the study. It is observed that the local thermal energy transfer rate enriches on increasing the value of both thermal and solute slips. The solutal slip parameter suppresses the solute transport rate and thermal slip supports the solute transport. Practical implications Combining the Dufour and Soret effects is used in oil reservoirs, binary alloy solidification and isotope separation in mixtures of gases. Heat exchangers, nuclear reactors and thermal engineering can all benefit from the usage of nanofluid with Joule heating. Social implications This study is mainly useful for thermal sciences and chemical engineering. Originality/value The investigation of the effects of slip circumstances and Joule heating on magnetohydrodynamic rotating nanoliquid stream with thermal radiation and cross-diffusion makes this work unique. The discoveries produced are valuable and distinctive, and they have applications in many areas of thermal science and technology.

Numerical Analysis of Heat Transfer and Flow Characteristics of Jeffrey Nanofluid Over Stretched Surfaces With MHD and Slip Effects

ABSTRACTThis study employs the Jeffrey fluid model to investigate stress relaxation in non‐Newtonian fluids, offering a more precise representation than conventional viscous models. It explores the influence of multiple slip conditions and magnetohydrodynamics (MHD) on Jeffrey fluid flow and heat transfer across irregular surfaces. Additionally, the impact of thermal radiation and internal heat sources on heat transfer is examined, essential for a comprehensive understanding of the system's thermal dynamics. Using the Buongiorno model, the diffusion and thermophoresis of nanoparticles within the flow are analyzed. Nonlinear coupled governing equations covering flow dynamics, heat transfer, and nanoparticle transport are transformed into ordinary differential equations (ODEs) through similarity transformations and solved numerically using the Runge–Kutta fourth‐order (RK4) method combined with shooting techniques. Results indicate significant effects of physical parameters on temperature, velocity, and mass profiles: a 20% decrease in temperature profiles with an increase in the dimensionless thermal slip coefficient from 0.1 to 0.5 and a 15% reduction in velocity profiles from a 0.1 unit increase in the magnetic parameter . The study also quantifies mass and heat transfer rates to elucidate their impacts. These findings have profound implications for engineering applications involving non‐Newtonian and nanofluids in complex geometrical configurations.

Effect of Wall Slip on the Extrusion Characteristics of 3D Printing of Cementitious Materials

AbstractThis paper investigates the impact of wall slip on the screw extrusion of cementitious materials. A wall slip extrusion model is developed based on the theory of infinite parallel plates. Then, the extrusion characteristics under different slip conditions of the screw and the cylinder wall are discussed. Finally, the Finite Element Method is used to verify the conclusions drawn from theoretical model analysis. The results show that when −1≤a←1/3 (where a is the ratio of pressure flow to the sum of drag flow and slip flow), slippage on either the screw wall or the cylinder wall can reduce the extrusion flow rate, and the number of flow recirculation planes is one. When −1/3≤a≤1, the number of flow recirculation planes increases to two, and screw wall slip is conducive to expanding the extrusion flow rate. Conversely, cylinder wall slip may reduce the extrusion flow rate. Moreover, the simulation results are consistent with those of the theoretical model, further verifying the rationality of the model.

Stabilization control of wheeled mobile robot based on neural sliding mode under wheel slip conditions

Stabilization control of wheeled mobile robot based on neural sliding mode under wheel slip conditions

Polarization force driven FHD flow over a permeable disc with geothermal viscosity

In this paper, we investigate the Bödewadt boundary layer flow of ferrous oxide-based electrically non-conducting Nanofluid considering the influence of thermal radiation and viscous dissipation over a permeable disc with slip conditions. Here, viscosity is taken as a function of temperature and depth. The equation of energy incorporates the radiative heat flux as described by the Rosseland approximation. The Von Kármán Model alters the constitutive nonlinear coupled partial differential equations of motion, which include slip boundary conditions. The final system of equations in PDE is solved computationally using a shooting approach in MATLAB with ode45, and the results are elucidated, through graphs and tables. The effects of all the above-considered physical entities including the geothermal viscosity on the velocity profile and temperature distribution over the disc are examined. An exhaustive analysis of all the above-investigated results is presented for the record. It is observed that the geothermal viscosity with considered boundary conditions retards the motion of the fluid causing decay in the net molecular movement and the thermal diffusion.

Optimization of heat transfer in bi-directional flow of sodium alginate-based ternary hybrid nanofluid over an extending heated surface with velocity slip conditions

Optimization of heat transfer in bi-directional flow of sodium alginate-based ternary hybrid nanofluid over an extending heated surface with velocity slip conditions

Effects of Air Vortex Finder Length and Outlet Diameter Variations on Oil Palm Loose Fruit Collector

Oil palm is one of the largest economy sectors in Malaysia. Among the problems faced in the estates are oil palm loose fruits deposition which is currently being collected manually in the industry. Hence, an oil palm loose fruit collector is designed using cyclone separator mechanism and was studied using computational fluid dynamics (CFD). In the current study, Reynold’s stress model (RSM) and the Discrete phase model (DPM) was employed to navigate numerical simulations where the vortex finder of the cyclone separator was varied with two factors which are the vortex finder length and outlet diameter. Wall was set to a no slip condition with standard wall functions. Hydraulic diameter of the gas outlet is Bc=0.1 . Hydraulic diameters of the particle’s outlet are Jc=0.15 and 0.2 respectively. Turbulence intensity at the gas and particles outlet are specified at 5%. An injection with density 995.7 and 0.04 was set to simulate oil palm loose fruit collection into the system. Ultimately, effects of vortex finder and outlet variations on the pressure drop and collection efficiency were then analyzed. Results indicate that an outlet diameter of 0.18 m and vortex finder length of 0.405 m is favourable for the oil palm loose fruit machine with a collection efficiency of 88.71 % and pressure drop of 477.66 Pa.

Magnetohydrodynamic flow of a hybrid nanofluid over an exponentially stretching sheet with joule heating and slip conditions using spectral collocation method with legendre wavelets

Magnetohydrodynamic flow of a hybrid nanofluid over an exponentially stretching sheet with joule heating and slip conditions using spectral collocation method with legendre wavelets

Analytical simulation for couple stress Williamson nanofluid flow and heat transfer towards a shrinking surface with slip and viscous dissipation effects

AbstractThis research work simulates analytically the flow and heat transfer properties of a couple stress Williamson nanofluid (WN) across a shrinking surface, accounting for the effects of slip and viscous dissipation. The Williamson and couple stress fluid model, using blood as the base fluid, tackles non‐Newtonian behavior. When there are slip conditions at the boundary, they change the velocity profile. Titanium dioxide and silver are used as nanoparticles, and blood is used as a base fluid for the formation of two different nanofluids. The study also looks at the role of viscous dissipation, which changes mechanical energy into thermal energy and adds to the energy equation. We use the homotopy analysis method (HAM) to analytically solve the governing nonlinear PDEs, which similarity transformations have converted into nonlinear ODEs. We thoroughly examine the effects of significant parameters, such as the couple stress parameter, Williamson fluid parameter, slip length, nanoparticle volume friction, and Eckert number (EN), on the temperature and velocity fields (VF). The results show how these factors interact in complex ways, giving us new ways to think about controlling and managing the heat of non‐Newtonian nanofluid flows in engineering settings.

Irreversibility analysis of ternary hybrid nanofluid flow through an oblique microchannel with Hall current: a comparative study

The ternary hybrid nanofluid is developed for application in engineering and technology such as oil extraction, converting solar thermal energy, and power storage. Hence the main aim of this study is to scrutinise the flow and irreversibility analysis of water based CuO − F e 3 O 4 hybrid nanofluid and CuO − F e 3 O 4 − Ag ternary hybrid nanofluid in an oblique microchannel. The influence of heat source coefficient, Hall current, nonlinear radiative heat flux and slip condition on the ternary nanofluid flow in a channel have been studied by considering buoyant force and the Buongiorno model. The dimensionless terms were employed to transform the governing partial differential equation into the ordinary differential equation. In the next step the RKF45 numerical technique is employed to crack the ordinary differential equations. The upshot elucidated that the intensified Hall parameter strongly supports the primary and secondary flow field. The thermophoretic parameter inflates with an augmented thermal field. A comparative analysis of ternary hybrid nanoliquid and hybrid nanoliquid has been made with the flow in an oblique channel. In the Bejan number and entropy, the ternary hybrid nanofluid is strongly supported than the hybrid nanofluid.

Boundary control of unsteady natural convective slip flow in reactive viscous fluids

We consider the optimal control of unsteady natural convective flow of reactive viscous fluid with heat transfer. It is assumed that Newton's law governs the heat transfer within an exothermic reaction under Arrhenius kinetics and Navier slip condition on the lower surface of the channel. The flow is examined in a vertical channel formed by two infinite vertical parallel plates, with a distance (H) between them. Time-dependent natural convective slip flow of reactive viscous fluid and heat transfer equations are solved in a unit interval using the Galerkin-Finite Element Method (FEM) with quadratic finite elements in space and the implicit Euler method in time. The direct solutions are obtained for testing various values of the problem parameters: the Biot number, the Frank Kamenetskii parameter, the Navier slip parameter, and the computation of the skin friction and the Nusselt number $(Nu)$. The optimal control problem is designed for the momentum and energy equations to derive the fluid-prescribed velocity and temperature profiles by defining controls on the boundary of the domain in two ways: (a) controls are formulated as parameters in the boundary conditions, such as slip length and Biot number; (b) controls are assigned as time-dependent functions in the boundary conditions, representing the slip velocity and the heat transfer rate. Following a discretize-then-optimize approach to the control problem, optimization is performed by the SLSQP (Sequential Least Squares Programming) algorithm, a subroutine of SciPy. Numerically simulated results show that the proposed approach successfully drives the flow to prescribed velocity and temperature profiles.

Mathematical Model of Bingham Fluid Inside Asymmetric Stenosed Artery and Its Applications

This study is to analysis the two-layered model of blood flow inside asymmetric stenosed artery with the consideration that blood behaves like a Newtonian and non-Newtonian fluid with different viscosities in the Peripheral layer and core regions. Further, in view of the existence of a velocity slip in blood flow regime, an axial slip condition as reported by many researchers is introduced at interface of the two-layers in the present analysis. The expressions for the flow characteristics namely the velocity profile, flow rate , the resistance to flow, the wall shear stress at the stenosis throat within the tube are obtained. Discussions are done from a physiological point of view with the help of graph.

Dynamics of variable thermal conductivity and multiple slip conditions in a Carreau hybrid nanofluid flow past a stretching sheet

AbstractThe influence of thermal radiation, multiple slip boundary conditions, and binary chemical reaction on the three‐dimensional circulation of unsteady magnetohydrodynamic (MHD) natural convection Carreau hybrid nanofluid () across a stretching sheet comprised of heat source/sink (H‐SS) and variable thermal conductivity are investigated. Runge‐Kutta‐Fehlberg 4th‐5th order (RKF‐45), in conjunction with the shooting approach, is utilized for numerical computation. Computed solutions indicate that the volume fraction of silicon dioxide and velocity slip parameters tends to retard the velocity profile. It is inferred from the graphs that temperature profile upsurges with enhancing the magnitude of thermal Grashof number, H‐SS parameter, mass Grashof number, variable conductivity parameter, and radiative parameter, whereas converse effects for thermal slip parameter. The chemical reaction parameter and solutal slip constraint tend to decrease the concentration profile. Furthermore, the heat transfer phenomenon uplifts with the consideration of radiative effects, while the mass transfer rate diminishes with enhancing the magnitude of magnetic parameters and activation energy.

Heat Generation Effect on 3D MHD Flow of Casson Fluid Via Porous Stretching/Shrinking Surface with Velocity Slip Condition

There are extensive range of applications related to nuclear industry, industrial manufacturing, science and engineering processing, in which the boundary layer hydromagnetic motion of Casson liquids perform vital role. Casson liquid is a useful liquid in the nuclear industry for optimizing the design and operation of nuclear reactors. Researchers have investigated transfer of heat in liquid motions with linear stratification, which is a phenomenon where the temperature varies linearly with height, affecting various fields such as medical equipment, glass fiber production, electronic devices, polymer sheets, paper production, filaments, and medicine. However, the most discussion of heat transfer problems is to get numerical solutions of a comprehensive Casson liquid model with heat generation described by the BVP4 via shooting method. In this study, a new velocity slip boundary condition is applied at the stretching or shrinking surface. These conditions are grounded in the previously established Buongiorno model, providing a more practical and realistic approach compared to previous study. The time independent Gov. Eqs. changed into a set of couple non-linear ODEs with help of suitable similarity conversions. The equations are evaluating via R-K-F by help of MATLAB software programming.

Interaction of induced magnetic field, double diffusion convection and multiple slips for thermal radiative biological flow of six-constant Jeffreys nanofluid: Advancements in mechanics

ABSTRACT The mathematical modeling of biological fluids holds paramount importance, given its diverse applications in the medical field. Understanding the peristaltic mechanism is crucial for gaining insights into various biological flows. This study focuses on numerically estimating the double-diffusive peristaltic flow of a non-Newtonian six constant Jefferys nanofluid within an irregular medium. The investigation considers the influences of nonlinear thermal emission, viscous dissolution, and induced magnetization, incorporating multiple slip conditions. The Buongiorno model is employed to underscore key features related to thermophoresis and Brownian diffusion coefficients. The convection of double diffusivity is elucidated through the Soret and Dufour variables. Lubrication technique is employed for mathematical simulation, and the resulting nonlinear coupled system of differential equations is solved numerically through the Mathematica program’s built-in command (ND Solve function). The graphical representation of the impact of crucial flow variables, such as nanoparticle volume proportion, pressure gradient, solute density, temperature, pressure fluctuation per wavelength, and velocity distribution, provides valuable insight. The findings of the current study show that an increase in the Prandtl number and thermophoresis parameter leads to the expansion of thermal curves. Moreover, it is also noted that rising heat frequencies of radiation cause the concentration of nanoparticles to increase.

Analysis of MHD slip blood flow through a constricted artery filled with a porous medium of variable permeability: Applications in Biomedical Engineering

The primary goal of this research is to investigate the impact of partial slip and variable permeability on the dynamics of blood flow in a constricted artery filled with a porous medium, and to assess the influence of an externally applied magnetic field on the blood flow. The blood is modeled as an incompressible Newtonian fluid. By employing a stream function formulation, the coupled nonlinear flow equations are transformed into a single dimensionless equation, which is solved using the Adomian decomposition method (ADM). Key parameters such as the slip parameter, permeability parameter, Hartmann number, and Reynolds number are examined in relation to their effects on the flow field. The results reveal significant changes in blood flow dynamics within the stenosed section of the artery, particularly due to the incorporation of variable permeability in the porous medium and the partial slip condition along the arterial wall in the presence of the magnetic field. Notable outcomes include the escalation in axial velocity with increasing permeability and slip, as well as the formation of flow separation and recirculation zones in regions of high stenosis height. Additionally, the magnetic field was found to suppress axial velocity while increasing shear stress, particularly near the throat of the stenosis. These findings provide deeper insights into how variable permeability and slip conditions influence blood flow in clinical scenarios such as magnetic resonance imaging (MRI). Importantly, the results in specific cases align with established findings from existing literature, validating the approach and offering new contributions to the understanding of MHD flow in constricted arteries.

Slippage flow of second-grade fluid over a vertical plate with thermo-diffusion effect: an application of hybrid fractional operator

This research investigates the effects of slip and thermo-diffusion on magnetohydrodynamic fluid flow and heat transfer through a porous medium, using a fractional second-grade fluid model. A semi-analytical solution is obtained through Laplace transform techniques, revealing detailed insights into concentration, temperature, and velocity distributions. The study sheds light on the significant impact of key parameters, including Prandtl and Schmidt numbers, Grashof numbers, and the second-grade parameter, on the intricate relationships between thermo-diffusion, slip conditions, and fluid flow in porous media.

Contribution of wall-attached momentum transfer structures to the skin friction in slip channel flows

Reducing the skin-friction drag in wall turbulence is crucial for minimizing energy consumption in various industrial applications. Although numerous studies have proposed strategies for skin-friction reduction, their effectiveness generally degrades at high Reynolds numbers (Re) owing to the multiscale nature of wall turbulence. To address this challenge, it is necessary to understand coherent structures that span a wider range at high Re, particularly those that extend down to the wall. Hence, we explore wall-attached momentum transfer structures in drag-reduced flows and investigate the associated Re effects on the skin-friction reduction. We perform direct numerical simulations of drag-reduced flows at two bulk Re of 10,000 and 20,000 by employing the Navier slip boundary condition. For comparison, we conduct no-slip cases at the same bulk Re. We extract clusters of intense ejections and sweeps responsible for momentum transfer in instantaneous flow fields. We observe that wall-attached momentum transfer structures play a dominant role in the turbulent skin friction quantified through the FIK identity (Fukagata et al., 2002). These structures are classified into buffer-layer, self-similar, and non-self-similar ones according to their height. The self-similar structures not only exhibit geometrical self-similarity but also maintain their Reynolds shear stress distribution relative to the local Reynolds shear stress under slip conditions. Moreover, these self-similar structures show nearly identical skin-friction reduction across all heights. In contrast, the non-self-similar structures exhibit a significant difference under slip conditions, especially at a high Re. The reduced area fraction and volume of non-self-similar structures, along with decreased wall-normal transport under slip conditions, result in a greater skin-friction reduction compared to that observed at the low Re. Our findings advance the understanding of the scale-dependent behavior of wall-attached structures in drag-reduced flows, paving the way for the development of new drag-reduction methods through the strategic manipulation of these structures.

Thermal effects of ternary Casson nanofluid flow over a stretching sheet: An investigation of Thomson and Troian velocity slip

The present research analyzes the properties of a Casson ternary nanofluid over a stretching sheet with Thomson and Troian slip conditions, taking into consideration the influences of electromagnetohydrodynamic (EMHD). The ternary nanofluid comprises three different nanoparticles, which include titanium dioxide (TiO2), copper (Cu), and silver (Ag), all being suspended in oil, which is the base fluid. They are involved because of their good thermal conductivity and chemical stability, and AgCuTiO2 /Oil nanofluid is a composite of copper, titanium oxide, and oil. Hence, carrying out the said procedure, the ternary nanofluid becomes AgCuTiO2/Oil. The sheet is, however, thought to be stretching vertically while the flow is determined by the effect of the gravity force through the free convention. Moreover, the phenomena of EMHD, porous medium, thermal slip, thermal radiation, Joule heating, and heat source/sink are included to make the energy equation more real-life. This leads to a set of partial differential equations (PDEs) based mathematical models transformed into ordinary differential equations (ODEs)-appropriate similarity transformation. The Runge–Kutta–Fehlberg (RKF-45) method solves the given ordinary differential system. According to the research’s findings, the temperature of the ternary Casson nanofluid rises when the suspension of silver, copper, and titanium dioxide nanoparticles increases, and the velocity of flow for merely silver and copper decreases when the density decreases. This causes the flow rate to be constricted through the velocity slip condition, at the same time as the nanofluid’s temperature increases.

Effect of Magnetic Field and Slip Conditions on Flow in a Rotating Porous Channel With Viscous Dissipation

ABSTRACTThis study examines the steady flow of an electrically conducting fluid through a rotating porous channel bounded by stationary, impermeable horizontal plates at constant temperature. The primary aim is to explore the combined effects of a magnetic field, wall slip conditions, and viscous dissipation. The channel rotates at a constant angular velocity, with slip conditions applied at the walls. A pressure gradient drives the primary flow, while rotation generates the secondary flow. Analytical solutions for velocity profiles and volumetric flow rates are obtained, and the temperature distribution is calculated using MATLAB's “bvp4c” function. The research offers novel insights into the behavior of primary and secondary flow velocities under different Hartmann and Taylor numbers, emphasizing the impact of slip conditions. Additionally, the influence of the Eckert number on temperature is analyzed in conjunction with these parameters. These findings contribute valuable theoretical perspectives for enhancing cooling systems in rotating machinery using conductive fluids in porous channels. This study opens avenues for future research to investigate unsteady flow conditions and the effects of variable magnetic fields and rotational speeds on fluid behavior in rotating porous channels.