The singularity of the UCM/Oldroyd-B models at a finite Weissenberg number, for the steady sphere translation with Navier slip on the sphere

2021 ◽  
pp. 104679
Author(s):  
Kostas D. Housiadas
Keyword(s):  
Weissenberg Number ◽  
Navier Slip

scholarly journals Fundamental flow problems considering non-Newtonian hyperbolic tangent fluid with Navier slip: Homotopy analysis method

2020 ◽  
Vol 14 (2) ◽  
Author(s):  
Lalrinpuia Tlau
Keyword(s):  
Skin Friction ◽  
Homotopy Analysis Method ◽  
Fluid Velocity ◽  
Weissenberg Number ◽  
Analysis Method ◽  
Hyperbolic Tangent ◽  
Navier Slip ◽  
Flow Problems ◽  
Flow Parameters ◽  
Homotopy Analysis

The presented research article deals with the classical fundamental flows (Poiseuille and Couette) of an incompressible hyperbolic tangent fluid while considering the Navier slip at the walls. The governing equations are solved using the homotopy analysis method. The velocity expressions are obtained for each problem and the effect of the flow parameters are discussed while being supplemented by graphical displays. Increasing the slip parameter reduces the fluid velocity for both problems, respectively. An increase in the Weissenberg number shows that skin friction at the lower wall reduces. This shows that a dominant elastic force is crucial in reducing the skin friction.

Log-Conformation and Square Root-Conformation Transformations in High Weissenberg Number Flows

2019 ◽  
Author(s):  
Beatriz Liara Carreira ◽  
Analice Costacurta Brandi ◽  
Laison Junio da Silva Furlan ◽  
Matheus Tozo de Araujo ◽  
Leandro Franco de Souza
Keyword(s):  
Weissenberg Number ◽  
Square Root

Peristaltic Carreau-Yasuda nanofluid flow and mixed heat transfer analysis in an asymmetric vertical and tapered wavy wall channel

2020 ◽  
Vol 1 (1) ◽  
pp. 128-140 ◽  
Author(s):  
Mohammad Hatami ◽  
◽  
D Jing ◽  
Keyword(s):  
Heat Transfer ◽  
Least Square Method ◽  
Weissenberg Number ◽  
Least Square ◽  
Heat Transfer Analysis ◽  
Phase Method ◽  
Nanofluid Flow ◽  
Two Phase ◽  
Nanoparticles Concentration ◽  
The Right

In this study, two-phase asymmetric peristaltic Carreau-Yasuda nanofluid flow in a vertical and tapered wavy channel is demonstrated and the mixed heat transfer analysis is considered for it. For the modeling, two-phase method is considered to be able to study the nanoparticles concentration as a separate phase. Also it is assumed that peristaltic waves travel along X-axis at a constant speed, c. Furthermore, constant temperatures and constant nanoparticle concentrations are considered for both, left and right walls. This study aims at an analytical solution of the problem by means of least square method (LSM) using the Maple 15.0 mathematical software. Numerical outcomes will be compared. Finally, the effects of most important parameters (Weissenberg number, Prandtl number, Brownian motion parameter, thermophoresis parameter, local temperature and nanoparticle Grashof numbers) on the velocities, temperature and nanoparticles concentration functions are presented. As an important outcome, on the left side of the channel, increasing the Grashof numbers leads to a reduction in velocity profiles, while on the right side, it is the other way around.

scholarly journals Measurement of Navier Slip on Individual Nanoparticles in Liquid

Nano Letters ◽  
2021 ◽  
Author(s):  
Jesse F. Collis ◽  
Selim Olcum ◽  
Debadi Chakraborty ◽  
Scott R. Manalis ◽  
John E. Sader
Keyword(s):  
Navier Slip ◽  
Individual Nanoparticles

scholarly journals Asymptotic analysis of an optimal control problem for a viscous incompressible fluid with Navier slip boundary conditions

2021 ◽  
pp. 1-21
Author(s):  
Claudia Gariboldi ◽  
Takéo Takahashi
Keyword(s):  
Optimal Control ◽  
Optimal Control Problem ◽  
Boundary Conditions ◽  
Control Problem ◽  
Stokes System ◽  
Navier Stokes ◽  
Slip Boundary Conditions ◽  
Navier Slip ◽  
Slip Boundary ◽  
Navier Slip Boundary Conditions

We consider an optimal control problem for the Navier–Stokes system with Navier slip boundary conditions. We denote by α the friction coefficient and we analyze the asymptotic behavior of such a problem as α → ∞. More precisely, we prove that if we take an optimal control for each α, then there exists a sequence of optimal controls converging to an optimal control of the same optimal control problem for the Navier–Stokes system with the Dirichlet boundary condition. We also show the convergence of the corresponding direct and adjoint states.

scholarly journals Convective Heat/Mass Transfer Analysis on Johnson-Segalman Fluid in a Symmetric Curved Channel with Peristalsis: Engineering Applications

Symmetry ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1475
Author(s):  
Humaira Yasmin ◽  
Naveed Iqbal ◽  
Aiesha Hussain
Keyword(s):  
Newtonian Fluid ◽  
Peristaltic Flow ◽  
Weissenberg Number ◽  
Concentration Profiles ◽  
Convective Conditions ◽  
Curved Channel ◽  
Regular Perturbation ◽  
Flexible Walls ◽  
Physical Level ◽  
Parameter Values

The peristaltic flow of Johnson–Segalman fluid in a symmetric curved channel with convective conditions and flexible walls is addressed in this article. The channel walls are considered to be compliant. The main objective of this article is to discuss the effects of curvilinear of the channel and heat/mass convection through boundary conditions. The constitutive equations for Johnson–Segalman fluid are modeled and analyzed under lubrication approach. The stream function, temperature, and concentration profiles are derived. The analytical solutions are obtained by using regular perturbation method for significant number, named as Weissenberg number. The influence of the parameter values on the physical level of interest is outlined and discussed. Comparison is made between Jhonson-Segalman and Newtonian fluid. It is concluded that the axial velocity of Jhonson-Segalman fluid is substantially higher than that of Newtonian fluid.

Effects of variable thermal conductivity and electrical conductivity on flow of williamson nanofluid between two parallel disks

2021 ◽  
Author(s):  
Mazmul Hussain ◽  
Nargis Khan
Keyword(s):  
Thermal Conductivity ◽  
Differential Equations ◽  
Electric Conductivity ◽  
Variable Temperature ◽  
Lewis Number ◽  
Variable Thermal Conductivity ◽  
Industrial Applications ◽  
Weissenberg Number ◽  
Modeling And Analysis ◽  
Variable Nature

The variable nature of the thermal conductivity of nanofluid with respect to temperature plays an important role in many engineering and industrial applications including solar collectors and thermoelectricity. Thus, the foremost motivation of this article is to investigate the effects of thermal conductivity and electric conductivity due to variable temperature on the flow of Williamson nanofluid. The flow is considered between two stretchable rotating disks. The mathematical modeling and analysis have been made in the presence of magnetohydrodynamic and thermal radiation. The governing differential equations of the problem are transformed into non-dimensional differential equations by using similarity transformations. The transformed differential equations are thus solved by a finite difference method. The behaviors of velocity, temperature and concentration profiles due to various parameters are discussed. For magnetic parameter, the radial and tangential velocities have showed decreasing behavior, while converse behavior is observed for axial velocity. The temperature profile shows increasing behavior due to an increase in the Weissenberg number, heat generation parameter and Eckert number, while it declines by increasing electric conductivity parameter. The nanoparticle concentration profile declines due to an increase in the Lewis number and Reynolds number.

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