Theoretical Study of the Reverse Roll Coating of Non-Isothermal Magnetohydrodynamics Viscoplastic Fluid

Abstract

This article describes the development of a mathematical model of the reverse roll coating of a thin film for an incompressible non-isothermal magnetohydrodynamics (MHD) viscoplastic fluid as it passes through a small gap between two rolls rotating reversely. The equations of motion required for the fluid added to the web are constructed and simplified using the lubrication approximation theory (LAT). Analytical results are obtained for the velocity profile, pressure gradient, and temperature distribution. The pressure distributions and flow rate are calculated numerically using the trapezoidal rule and regular false position method, respectively. Some of these results are presented graphically, while others are shown in a tabular form. From the present analysis, it has been observed that the magnitude of pressure distributions increases by increasing the value of the involved parameters. It is worth mentioning that the velocities ratio and Brickman’s number are controlling parameters for the temperature distributions. The results indicate the strong effectiveness of the viscoplastic parameter and velocities ratio for the velocity and pressure distributions. It is also concluded that the coating of Casson material has been remarkably affected by the magnetohydrodynamics effects.

A Theoretical Study of Reverse Roll Coating for a Non-Isothermal Third-Grade Fluid under Lubrication Approximation Theory

“…e innovation of the effort is inspired by the necessity from the coating manufacturing to uniform thin, faster, and coat stable layers, by coating rheology and operating coater operating conditions. e theoretical study of reverse roll coating of non-isothermal, an incompressible, magnetohydrodynamic viscoplastic fluid has been deliberated by Ali et al [39]. e governing equation of flow added to the sheet in the basic form was achieved by employing the technique of lubrication approximation.…”

Operational Stability Analysis on the Roller-Coating Process for a Roll Coating-Simulation Test Equipment

“…With the advancement of China's national strategic goal of "Carbon Peak" and "Carbon neutral", in recent years, it has attracted extensive attention and has been developed [1]. However, in terms of the coating materials in practical applications, it is found that in the roller-coating process, due to the influence of the temperature, viscosity, roller speed, vibration stability, and other factors of the coating, the coating material will form bubbles on the surface of the steel plate, resulting in defects on the surface of the coating, and some parameters for the stability of the coating material have to be evaluated before a coating implementation [2]. Therefore, a test equipment is needed to evaluate the roll coating performance of coating materials.…”

MHD Eyring–Powell nanofluid flow across a wedge with convective and thermal radiation

“…Therefore, great devotion has been devoted to the study of several non-Newtonian fluid models as a single constitutive expression, which is not suitable for representing the relationship between stress and shear rates of different fluids. Researchers are currently very interested in non-Newtonian fluid models and have been examined in a variety of contexts (Ali et al, 2020;Azam, 2022a;Ali et al, 2022;Azam et al, 2022;Azam, 2022b). The Eyring-Powell material model has several advantages: 1) it is a model based on the kinetic theory; 2) it describes the characteristics of shear-thinning fluids; and 3) the characteristics of Newtonian materials can be recovered for high shear rates.…”