Blade coating analysis of viscous nanofluid having Cu–water nanoparticles using flexible blade coater

2020 ◽  
Vol 36 (4) ◽  
pp. 348-367 ◽  
Author(s):  
Marya Kanwal ◽  
Xinhua Wang ◽  
Hasan Shahzad ◽  
Yingchun Chen ◽  
Hui Chai
Keyword(s):  
Pressure Gradient ◽  
Shooting Method ◽  
Volume Fraction ◽  
Volumetric Flow Rate ◽  
Lubrication Approximation ◽  
Nanoparticle Volume Fraction ◽  
Porous Substrate ◽  
Flow Equations ◽  
The Impact ◽  
Blade Coating

This article presents the blade coating analysis of viscous nanofluid passing over a porous substrate using a flexible blade coater. Water-based copper nanoparticles are considered to discuss the blade coating process. The lubrication approximation theory is applied to develop the flow equations. The analytical solution is obtained for velocity, volumetric flow rate, and pressure gradient, while shooting method is applied to obtain the pressure, thickness, and load. Different models for dynamic viscosity have been applied to observe the impact of related parameters on pressure, pressure gradient, and velocity. These results are presented graphically. Interesting engineering quantities such as load, deflection, and thickness are computed numerically and are shown in the tabulated form. It is found that nanoparticle volume fraction increases the pressure gradient, pressure and has minor effects on velocity. For model 1, an increase in the volume fraction reduces the coating thickness, load, and deflection, while model 2 has opposite effects on the mentioned quantities. Also, model 2 has a greater impact on pressure and pressure gradient when compared to model 1.

Calendering analysis of non-isothermal viscous nanofluid containing Cu-water nanoparticles using two co-rotating rolls

2020 ◽  
pp. 875608792095161
Author(s):  
Zaheer Abbas ◽  
Sabeeh Khaliq
Keyword(s):  
Temperature Distribution ◽  
Pressure Gradient ◽  
Dynamic Viscosity ◽  
Volume Fraction ◽  
Fluid Velocity ◽  
Power Input ◽  
Physical Parameters ◽  
Nanoparticle Volume Fraction ◽  
Flow Equations ◽  
The Impact

This study is a non-isothermal analysis of the calendering process using a water based nanofluid with Cu-nanoparticles. The basic flow equations are simplified under the lubrication approximation theory (LAT) and non-dimensionalized. Theoretical velocity and pressure gradient solutions are achieved, and temperature distribution is numerically computed by finite difference method. The impact of nanoparticle volume fraction on pressure distribution, fluid velocity, temperature distribution, power input, and separating force are presented through graphs and discussed. Nanoparticle volume fraction enhances the magnitude of pressure, pressure gradient, and temperature distribution. Power input and roll-separating force also rise for higher nanoparticle volume fraction. Model II of dynamic viscosity of nanofluid has a greater impact on physical parameters as compared to the model I of dynamic viscosity.

A theoretical analysis of roll-over-web coating assessment of viscous nanofluid containing Cu-water nanoparticles

2019 ◽  
Vol 36 (1) ◽  
pp. 55-75 ◽  
Author(s):  
Sabeeh Khaliq ◽  
Zaheer Abbas
Keyword(s):  
Pressure Gradient ◽  
Volume Fraction ◽  
Power Input ◽  
Lubrication Approximation ◽  
Nanoparticle Volume Fraction ◽  
Cu Nanoparticles ◽  
Roll Coating ◽  
Inverse Effect ◽  
Physical Quantities ◽  
The Web

The roll-coating analysis of viscous nanofluid using lubrication approximation theory over a flat porous sheet is investigated. We considered water-based copper ( Cu) nanoparticles to discuss the roll-coating analysis. The rate of fluid entering at the roll surface is assumed equal to the rate of fluid leaving on the web surface. The resulting differential equation developed under lubrication approximation and closed-form expressions is obtained for velocity and pressure gradient. The effects of entering velocity, Reynolds number, geometric parameter, and nanoparticle volume fraction with different models on physical quantities such as pressure, pressure gradient, velocity, force, power input are calculated. Some of these effects are presented graphically. It is noted that increasing nanoparticle volume fraction increases the pressure gradient, pressure distribution and has negligible effect on the velocity profile. Model II has a greater effect on pressure and pressure gradient than model I and has an inverse effect on force and power factor.

scholarly journals Mathematical modeling of slip and magnetohydrodynamics effects in blade coating

2018 ◽  
Vol 35 (1) ◽  
pp. 9-21 ◽  
Author(s):  
M Sajid ◽  
H Shahzad ◽  
M Mughees ◽  
N Ali
Keyword(s):  
Magnetic Field ◽  
Applied Magnetic Field ◽  
Shooting Method ◽  
Hartmann Number ◽  
Volumetric Flow Rate ◽  
Maximum Pressure ◽  
Slip Parameter ◽  
Slip Effects ◽  
Blade Coating ◽  
The Web

A mathematical analysis for magnetohydrodynamics and slip effects is presented for blade coating onto a moving sheet of viscous fluid. An applied magnetic field is imposed normal to the flow and slip is considered at the web surface. The shooting method is applied to obtain the numerical solution of governing differential equations. Both numerical and exact solutions are utilized to describe the velocity profile, volumetric flow rate, pressure gradient, pressure and maximum pressure. How slip parameter and the Hartmann number influences properties is discussed through the graphical results. It is calculated that the presence of slip and applied magnetic field controls the sheet velocity in the blade coating process.

scholarly journals Homotopy Semi-Numerical Modeling of Non-Newtonian Nanofluid Transport External to Multiple Geometries Using a Revised Buongiorno Model

Inventions ◽  
2019 ◽  
Vol 4 (4) ◽  
pp. 54 ◽  
Author(s):  
Atul Kumar Ray ◽  
Buddakkagari Vasu ◽  
O. Anwar Bég ◽  
Rama S.R. Gorla ◽  
P.V.S.N. Murthy
Keyword(s):  
Wall Temperature ◽  
Volume Fraction ◽  
Convective Boundary Condition ◽  
Computational Time ◽  
Nanoparticle Volume Fraction ◽  
Convective Boundary ◽  
Power Series Method ◽  
Fiber Technology ◽  
Buongiorno Model ◽  
The Impact

A semi-analytical solution for the convection of a power-law nanofluid external to three different geometries (i.e., cone, wedge and plate), subject to convective boundary condition is presented. A revised Buongiorno model is employed for the nanofluid transport over the various geometries with variable wall temperature and nanoparticle concentration conditions (non-isothermal and non-iso-solutal). Wall transpiration is included. The dimensional governing equations comprising the conservation of mass, momentum, energy and nanoparticle volume fraction are transformed to dimensionless form using appropriate transformations. The transformed equations are solved using a robust semi-analytical power series method known as the Homotopy analysis method (HAM). The convergence and validation of the series solutions is considered in detail. The variation of order of the approximation and computational time with respect to residual errors for temperature for the different geometries is also elaborated. The influence of thermophysical parameters such as wall temperature parameter, wall concentration parameter for nanofluid, Biot number, thermophoresis parameter, Brownian motion parameter and suction/blowing parameter on the velocity, temperature and nanoparticle volume fraction is visualized graphically and tabulated. The impact of these parameters on the engineering design functions, e.g., coefficient of skin fraction factor, Nusselt number and Sherwood number is also shown in tabular form. The outcomes are compared with the existing results from the literature to validate the study. It is found that thermal and solute Grashof numbers both significantly enhance the flow velocity whereas they suppress the temperature and nanoparticle volume fraction for the three different configurations, i.e., cone, wedge and plate. Furthermore, the thermal and concentration boundary layers are more dramatically modified for the wedge case, as compared to the plate and cone. This study has substantial applications in polymer engineering coating processes, fiber technology and nanoscale materials processing systems.

Calendering of non-isothermal Rabinowitsch fluid

2018 ◽  
Vol 38 (1) ◽  
pp. 83-92 ◽  
Author(s):  
Muhammad Sajid ◽  
Hira Siddique ◽  
Nasir Ali ◽  
Muhammad Asif Javed
Keyword(s):  
Temperature Distribution ◽  
Pressure Gradient ◽  
Energy Equation ◽  
Fluid Model ◽  
Sheet Thickness ◽  
Lubrication Approximation ◽  
Flow Equations ◽  
Hybrid Numerical Method ◽  
Isothermal Analysis ◽  
Roll Separating Force

Abstract: A non-isothermal analysis of calendering by using the Rabinowitsch fluid model is presented in this article. The flow equations are simplified by utilizing the lubrication approximation theory. The exact expressions of velocity and pressure gradient are obtained. The pressure distribution and engineering quantities are computed numerically by employing the Runge-Kutta algorithm. The temperature distribution is obtained by solving the energy equation numerically using the hybrid numerical method. The influence of the involved parameters on the velocity profile, pressure, pressure gradient and mechanical quantities such as roll-separating force, power function and exiting sheet thickness are shown graphically. The temperature distribution at various axial points is also shown through graphs.

An Investigation of the Forced Convection and Heat Transfer with a Cylindrical Agitator Subjected to Non-Newtonian Nanofluids

2018 ◽  
Vol 73 (9) ◽  
pp. 869-882
Author(s):  
Botong Li ◽  
Liancun Zheng ◽  
Liangliang Zhu ◽  
Tao Liu ◽  
Wei Zhang
Keyword(s):  
Heat Transfer ◽  
Forced Convection ◽  
Volume Fraction ◽  
Temperature Fields ◽  
Nanoparticle Volume Fraction ◽  
Newtonian Flow ◽  
Convection And Heat Transfer ◽  
Velocity And Temperature Fields ◽  
Laminar Forced Convection ◽  
The Impact

AbstractThe present research performed a numerical simulation of laminar forced convection nanofluid-based non-Newtonian flow in a channel connecting a tank with heating regions. To achieve a rapid diffusion of heat, a cylindrical agitator is inserted into the tank. Power-law modelling is employed to describe the effect of non-Newtonian behaviour. The velocity and temperature fields and heat transfer coefficient ratio are studied systematically, taking into account the impact of various parameters, such as the generalised Reynolds number Re, generalised Prandtl number Pr, angular velocity of a cylinderω, nanoparticle volume fractionϕ, mixer size and location. Our research reveals that, to improve the heat transfer in practice, several applicable strategies are available, including the addition of more nanoparticles into the base fluid, which proved to be the most efficient method to enhance the heat transfer of a nanofluid.

scholarly journals Diffusion and flow across shape-perturbed plasmodesmata nanopores in plants

2021 ◽  
Vol 136 (8) ◽  
Author(s):  
Anneline H. Christensen ◽  
Howard A. Stone ◽  
Kaare H. Jensen
Keyword(s):  
Flow Rate ◽  
Radial Displacement ◽  
Plant Cells ◽  
Volumetric Flow Rate ◽  
Lubrication Approximation ◽  
Pore Shape ◽  
Transport Capacity ◽  
Pressure Driven Flow ◽  
The Impact ◽  
Pressure Driven

AbstractPlasmodesmata are slender nanochannels that link neighboring plant cells and enable the exchange of nutrients and signaling molecules. Recent experiments have demonstrated significant variability in the concentric pore shape. However, the impact of these geometric fluctuations on transport capacity is unknown. Here, we consider the effects on diffusion and advection of two ideal shape perturbations: a radial displacement of the entire central desmotubule and a harmonic variation in the cytoplasmic sleeve width along the length of the pore. We use Fick’s law and the lubrication approximation to determine the diffusive current and volumetric flow rate across the pore. Our results indicate that an off-center desmotubule always increases the pressure-driven flow rate. However, the diffusive current is only enhanced for particles comparable in size to the width of the channel. In contrast, harmonic variations in the cytoplasmic sleeve width along the length of the pore reduce both the diffusive current and the pressure-driven flow. The simple models presented here demonstrate that shape perturbations can significantly influence transport across plasmodesmata nanopores.

Peristaltic transport of an aqueous solution of silver nanoparticles with convective heat transfer at the boundaries

2015 ◽  
Vol 93 (10) ◽  
pp. 1190-1198 ◽  
Author(s):  
F.M. Abbasi ◽  
T. Hayat ◽  
B. Ahmad
Keyword(s):  
Heat Transfer ◽  
Silver Nanoparticles ◽  
Shooting Method ◽  
Volume Fraction ◽  
Coupled System ◽  
Graphical Analysis ◽  
Peristaltic Transport ◽  
Nanoparticle Volume Fraction ◽  
Symmetric Channel ◽  
Source Sink

Peristaltic transport of water-based silver nanoparticles in a symmetric channel with convective walls is explored. Analysis has been carried out in the presence of heat source–sink, viscous dissipation, and mixed convection. Lubrication approach has been utilized. Resulting coupled system is solved numerically using the shooting method. Graphical analysis for flow quantities and heat transfer has been made. Results show that the addition of silver nanoparticles considerably reduces the velocity and temperature of the fluid. Enhancement in heat transfer rate at the wall for large nanoparticle volume fraction is also reported. Interesting outcomes of this study are summarized.

The formulation of the RANS equations for supersonic and hypersonic turbulent flows

2020 ◽  
pp. 1-31
Author(s):  
H. Zhang ◽  
T.J. Craft ◽  
H. Iacovides
Keyword(s):  
Kinetic Energy ◽  
Pressure Gradient ◽  
Turbulent Kinetic Energy ◽  
Turbulent Flows ◽  
High Speed ◽  
Mean Flow ◽  
Rans Equations ◽  
Flow Equations ◽  
The Mean ◽  
The Impact

Abstract Accurate prediction of supersonic and hypersonic turbulent flows is essential to the design of high-speed aerospace vehicles. Such flows are mainly predicted using the Reynolds-Averaged Navier–Stokes (RANS) approach in general, and in particular turbulence models using the effective viscosity approximation. Several terms involving the turbulent kinetic energy (k) appear explicitly in the RANS equations through the modelling of the Reynolds stresses in such approach, and similar terms appear in the mean total energy equation. Some of these terms are often ignored in low, or even supersonic, speed simulations with zero-equation models, as well as some one- or two-equation models. The omission of these terms may not be appropriate under hypersonic conditions. Nevertheless, this is a widespread practice, even for very high-speed turbulent flow simulations, because many software packages still make such approximations. To quantify the impact of ignoring these terms in the RANS equations, two linear two-equation models and one non-linear two-equation model are applied to the computation of five supersonic and hypersonic benchmark cases, one 2D zero-pressure gradient hypersonic flat plate case and four shock wave boundary layer interaction (SWBLI) cases. The surface friction coefficients and velocity profiles predicted with different combinations of the turbulent kinetic energy terms present in the transport equations show little sensitivity to the presence of these terms in the zero-pressure gradient case. In the SWBLI cases, however, comparisons show that inclusion of k in the mean flow equations can have a strong effect on the prediction of flow separation. Therefore, it is highly recommended to include all the turbulent kinetic energy terms in the mean flow equations when dealing with simulations of supersonic and hypersonic turbulent flows, especially for flows with SWBLIs. As a further consequence, since k may not be obtained explicitly in zero-equation, or certain one-equation, models, it is debatable whether these models are suitable for simulations of supersonic and hypersonic turbulent flows with SWBLIs.

scholarly journals Heat Transfer Analysis of 3-D Viscoelastic Nanofluid Flow Over a Convectively Heated Porous Riga Plate with Cattaneo-Christov Double Flux

2021 ◽  
Vol 9 ◽  
Author(s):  
K. Loganathan ◽  
Nazek Alessa ◽  
Safak Kayikci
Keyword(s):  
Brownian Motion ◽  
Volume Fraction ◽  
Fluid Velocity ◽  
Heat Transfer Analysis ◽  
Fluid Temperature ◽  
Heat Absorption ◽  
Nanoparticle Volume Fraction ◽  
Riga Plate ◽  
Viscoelastic Nanofluid ◽  
The Impact

The impact of heat-absorbing viscoelastic nanofluidic flow along with a convectively heated porous Riga plate with Cattaneo-Christov double flux was analytically investigated. The Buongiorno model nanofluid was implemented with the diversity of Brownian motion and thermophoresis. Making use of the transformations; the PDE systems are altered into an ODE system. We use the homotopy analysis method to solve these systems analytically. The reaction of the apposite parameters on fluid velocity, fluid temperature, nanoparticle volume fraction skin friction coefficients (SFC), local Nusselt number and local Sherwood number are shown with vividly explicit details. It is found that the fluid velocities reflect a declining nature for the development of viscoelastic and porosity parameters. The liquid heat becomes rich when escalating the radiation parameter. In addition, the nanoparticle volume fraction displays a declining nature towards the higher amount of thermophoresis parameter, whereas the inverse trend was obtained for the Brownian motion parameter. We also found that the fluid temperature is increased in viscoelastic nanofluid compared to the viscous nanofluid. When we change the fluid nature from heat absorption to heat generation, the liquid temperature also rises. In addition, the fluid heat is suppressed when we change the flow medium from a stationary plate to a Riga plate for heat absorption/generation cases.

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