Analysis of calendering process of non-isothermal flow of non-Newtonian fluid: A perturbative and numerical study

2021 ◽  
pp. 875608792097902
Author(s):  
S Khaliq ◽  
Z Abbas
Keyword(s):  
Numerical Study ◽  
Perturbation Technique ◽  
Power Input ◽  
Third Order ◽  
Flow Equations ◽  
Tridiagonal Matrix Algorithm ◽  
Engineering Parameters ◽  
Basic Equations ◽  
Roll Separating Force ◽  
The Impact

This paper numerically solves the third-order fluid flow during calendering with slip condition at the rolls. The basic equations are transformed into dimensionless forms and simplified by adopting LAT (Lubrication Approximation Theory). The flow equations are then solved with the perturbation technique. Whereas a finite difference scheme along with TDMA (Tridiagonal Matrix Algorithm) is implemented to solve the energy equation. Engineering parameters like power input, exit distance, and roll separating force are computed. The impact of slip parameter [Formula: see text] and material parameter [Formula: see text] on the velocity profile, pressure, pressure gradient, temperature profile, power input, detachment point, and roll separating force is portrayed through graphs and discussed. It is noticed that both the parameters [Formula: see text] and [Formula: see text] exhibit opposite behaviors and give insight to the mechanisms that control the physical and engineering parameters.

Numerical analysis of the calendering process by using Giesekus fluid model

2019 ◽  
Vol 36 (2) ◽  
pp. 167-190 ◽  
Author(s):  
Muhammad Asif Javed ◽  
Nasir Ali ◽  
Sabeen Arshad
Keyword(s):  
Pressure Gradient ◽  
Power Function ◽  
Numerical Study ◽  
Fluid Model ◽  
Sheet Thickness ◽  
Deborah Number ◽  
Flow Equations ◽  
Giesekus Fluid ◽  
Engineering Parameters ◽  
Roll Separating Force

A numerical study of the calendering process is presented. The material to be calendered is modeled by using Giesekus constitutive equation. The flow equations are first presented in dimensionless forms and then simplified by incorporating the lubrication approximation theory. The resulting equations are analytically solved for the stream function. The pressure gradient, pressure, and other engineering parameters related to the calendering process, such as roll-separating force, power function, and entering sheet thickness, are numerically calculated by using Runge–Kutta algorithm. The influence of the Giesekus parameter and the Deborah number on the velocity profile, pressure gradient, pressure, power function, roll-separating force, and exiting sheet thickness are discussed in detail with the help of various graphs. The present analysis indicates that the pressure in the nip region decreases with increasing Giesekus parameter and Deborah number. The power function and the roll-separating force exhibit decreasing trends with increasing Deborah number. The exiting sheet thickness decreases up to a certain entering sheet thickness, as compared to the Newtonian case. Beyond this entering sheet thickness, the exiting sheet thickness increases with increasing entering sheet thickness.

scholarly journals Analytical Investigation of Magnetohydrodynamic Non-Newtonian Type Casson Nanofluid Flow past a Porous Channel with Periodic Body Acceleration

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
N. Thamaraikannan ◽  
S. Karthikeyan ◽  
Dinesh Kumar Chaudhary ◽  
Safak Kayikci
Keyword(s):  
Differential Equations ◽  
Thermal Radiation ◽  
Perturbation Technique ◽  
Analytical Investigation ◽  
Porous Channel ◽  
Body Acceleration ◽  
Casson Nanofluid ◽  
Flow Equations ◽  
Flow Features ◽  
The Impact

The consequence of periodic body acceleration and thermal radiation in the pulsating flow of MHD Casson nanofluid through a porous channel is addressed. A flow of the nanofluid injected through the lower plate is considered while sucked out through the upper plate with a similar velocity. The thermal radiation term is incorporated in the heat transfer equation. The governing equations corresponding to velocity and temperature are converted from partial differential equations to a system of ordinary differential equations by employing similarity variables. The perturbation technique is applied to solve the governing flow equations. The impact of diverse parameters on flow features is graphically analyzed. The result reveals that adding the nanoparticle has enhanced the velocity profile of the base fluid. Moreover, an increase in the periodic body acceleration results in enlarging velocity and temperature.

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.

Analysis of the lubrication approximation theory in the calendering/sheeting process of upper convected Jeffery’s material

2020 ◽  
pp. 875608792096254
Author(s):  
M Zahid ◽  
NZ Khan ◽  
AM Siddiqui ◽  
S Iqbal ◽  
A Muhammad ◽  
...  
Keyword(s):  
Pressure Distribution ◽  
Flow Rate ◽  
Approximation Theory ◽  
Material Parameter ◽  
Sheet Thickness ◽  
Power Input ◽  
Lubrication Approximation ◽  
Flow Equations ◽  
Velocity Flow ◽  
Roll Separating Force

This paper analyses an isothermal calendering for an upper convected Jeffery’s Material. Lubrication Approximation Theory (LAT) is applied to simplify the flow equations. Analytical solutions of velocity, flow rate, and pressure gradient are carried out. Outcomes of sheet thickness, detachment point, roll separating force, power input to the roll, and pressure distribution are obtained. The effects of some involved parameters are displayed through graphs and tables. It is noted that the material parameter is a controlling device for sheet thickness, flow rate, detachment point, roll separating force, power input, and the pressure distribution. We observed that as the material parameter increases, the detachment point increases which results in increased sheet thickness.

scholarly journals Oscillatory Flow MHD of Jeffrey Fluid with Temperature-Dependent Viscosity (TDV) in a Saturated Porous Channel

2021 ◽  
pp. 27-34
Author(s):  
Wissam Sadiq Khudair ◽  
Hasan Hadi Dwail ◽  
Hayder Kadim Mohammed
Keyword(s):  
Magnetic Parameter ◽  
Perturbation Technique ◽  
Porous Channel ◽  
Jeffrey Fluid ◽  
Physical Parameters ◽  
Temperature Dependent ◽  
Temperature Dependent Viscosity ◽  
Flow Equations ◽  
Dependent Viscosity ◽  
The Impact

In this research, we studied the impact of Magnetohydrodynamic (MHD) on Jeffrey fluid with porous channel saturated with temperature-dependent viscosity (TDV). It is obtained on the movement of fluid flow equations by using the method of perturbation technique in terms of number Weissenberg ( ) to get clear formulas for the field of velocity. All the solutions of physical parameters of the Reynolds number , Magnetic parameter , Darcy parameter , Peclet number  and are discussed under the different values, as shown in the plots.

scholarly journals Model of thermal buoyancy in cavity-ventilated roof constructions

2021 ◽  
pp. 174425912098418
Author(s):  
Toivo Säwén ◽  
Martina Stockhaus ◽  
Carl-Eric Hagentoft ◽  
Nora Schjøth Bunkholt ◽  
Paula Wahlgren
Keyword(s):  
Analytical Model ◽  
Flow Rate ◽  
Numerical Study ◽  
Air Flow ◽  
Wind Pressure ◽  
Air Flow Rate ◽  
Test Set ◽  
Air Cavity ◽  
Thermal Buoyancy ◽  
The Impact

Timber roof constructions are commonly ventilated through an air cavity beneath the roof sheathing in order to remove heat and moisture from the construction. The driving forces for this ventilation are wind pressure and thermal buoyancy. The wind driven ventilation has been studied extensively, while models for predicting buoyant flow are less developed. In the present study, a novel analytical model is presented to predict the air flow caused by thermal buoyancy in a ventilated roof construction. The model provides means to calculate the cavity Rayleigh number for the roof construction, which is then correlated with the air flow rate. The model predictions are compared to the results of an experimental and a numerical study examining the effect of different cavity designs and inclinations on the air flow rate in a ventilated roof subjected to varying heat loads. Over 80 different test set-ups, the analytical model was found to replicate both experimental and numerical results within an acceptable margin. The effect of an increased total roof height, air cavity height and solar heat load for a given construction is an increased air flow rate through the air cavity. On average, the analytical model predicts a 3% higher air flow rate than found in the numerical study, and a 20% lower air flow rate than found in the experimental study, for comparable test set-ups. The model provided can be used to predict the air flow rate in cavities of varying design, and to quantify the impact of suggested roof design changes. The result can be used as a basis for estimating the moisture safety of a roof construction.

scholarly journals Numerical Simulation of the Impact of the Heat Source Position on Melting of a Nano-Enhanced Phase Change Material

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1425
Author(s):  
Tarek Bouzennada ◽  
Farid Mechighel ◽  
Kaouther Ghachem ◽  
Lioua Kolsi
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Phase Change Material ◽  
Numerical Study ◽  
Melting Rate ◽  
Heat Transfer Fluid ◽  
Commercial Code ◽  
Tube Position ◽  
The Impact ◽  
Change Material

A 2D-symmetric numerical study of a new design of Nano-Enhanced Phase change material (NEPCM)-filled enclosure is presented in this paper. The enclosure is equipped with an inner tube allowing the circulation of the heat transfer fluid (HTF); n-Octadecane is chosen as phase change material (PCM). Comsol-Multiphysics commercial code was used to solve the governing equations. This study has been performed to examine the heat distribution and melting rate under the influence of the inner-tube position and the concentration of the nanoparticles dispersed in the PCM. The inner tube was located at three different vertical positions and the nanoparticle concentration was varied from 0 to 0.06. The results revealed that both heat transfer/melting rates are improved when the inner tube is located at the bottom region of the enclosure and by increasing the concentration of the nanoparticles. The addition of the nanoparticles enhances the heat transfer due to the considerable increase in conductivity. On the other hand, by placing the tube in the bottom area of the enclosure, the liquid PCM gets a wider space, allowing the intensification of the natural convection.

OPTIMAL REINSURANCE FROM THE VIEWPOINTS OF BOTH AN INSURER AND A REINSURER UNDER THE CVAR RISK MEASURE AND VAJDA CONDITION

2021 ◽  
pp. 1-29
Author(s):  
Yanhong Chen
Keyword(s):  
Loss Function ◽  
Value At Risk ◽  
Numerical Study ◽  
Risk Measure ◽  
Convex Combination ◽  
Weighting Factor ◽  
Loss Functions ◽  
Conditional Value At Risk ◽  
Optimal Reinsurance ◽  
The Impact

ABSTRACT In this paper, we study the optimal reinsurance contracts that minimize the convex combination of the Conditional Value-at-Risk (CVaR) of the insurer’s loss and the reinsurer’s loss over the class of ceded loss functions such that the retained loss function is increasing and the ceded loss function satisfies Vajda condition. Among a general class of reinsurance premium principles that satisfy the properties of risk loading and convex order preserving, the optimal solutions are obtained. Our results show that the optimal ceded loss functions are in the form of five interconnected segments for general reinsurance premium principles, and they can be further simplified to four interconnected segments if more properties are added to reinsurance premium principles. Finally, we derive optimal parameters for the expected value premium principle and give a numerical study to analyze the impact of the weighting factor on the optimal reinsurance.

scholarly journals A numerical study of the impact perforation of sandwich panels with graded hollow sphere cores

2021 ◽  
Vol 13 (4) ◽  
pp. 168781402110094
Author(s):  
Ibrahim Elnasri ◽  
Han Zhao
Keyword(s):  
Boundary Conditions ◽  
Hollow Sphere ◽  
Sandwich Panel ◽  
Numerical Study ◽  
Sandwich Panels ◽  
Hopkinson Bar ◽  
Core Density ◽  
The Core ◽  
The Impact ◽  
Force Displacement

In this study, we numerically investigate the impact perforation of sandwich panels made of 0.8 mm 2024-T3 aluminum alloy skin sheets and graded polymeric hollow sphere cores with four different gradient profiles. A suitable numerical model was conducted using the LS-DYNA code, calibrated with an inverse perforation test, instrumented with a Hopkinson bar, and validated using experimental data from the literature. Moreover, the effects of quasi-static loading, landing rates, and boundary conditions on the perforation resistance of the studied graded core sandwich panels were discussed. The simulation results showed that the piercing force–displacement response of the graded core sandwich panels is affected by the core density gradient profiles. Besides, the energy absorption capability can be effectively enhanced by modifying the arrangement of the core layers with unclumping boundary conditions in the graded core sandwich panel, which is rather too hard to achieve with clumping boundary conditions.

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