scholarly journals Numerical Analysis of Carbon Nanotube-Based Nanofluid Unsteady Flow Amid Two Rotating Disks with Hall Current Coatings and Homogeneous–Heterogeneous Reactions

Coatings ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 48 ◽  
Author(s):  
Muhammad Ramzan ◽  
Saima Riasat ◽  
Seifedine Kadry ◽  
Pin Kuntha ◽  
Yunyoung Nam ◽  
...  
Keyword(s):  
Thermal Stratification ◽  
Hall Current ◽  
Tangential Velocity ◽  
Heterogeneous Reactions ◽  
Fluid Temperature ◽  
Rotating Disks ◽  
Temperature Parameter ◽  
Comparison Table ◽  
Physical Laws ◽  
Limiting Case

In the present exploration, our objective is to investigate the importance of Hall current coatings in the establishment of Cattaneo–Christov (CC) heat flux model in an unsteady aqueous-based nanofluid flow comprising single (SWCNTs) and multi-walled (MWCNTs) carbon nanotubes (CNTs) amid two parallel rotating stretchable disks. The novelty of the presented model is strengthened with the presence of homogeneous-heterogeneous (HH) reactions and thermal stratification effects. The numerical solution of the system of coupled differential equations with high nonlinearity is obtained by applying the bvp4c function of MATLAB software. To corroborate the authenticity of the present envisioned mathematical model, a comparison table is added to this study in limiting case. An excellent harmony between the two results is obtained. Effects of numerous parameters on involved distributions are displayed graphically and are argued logically in the light of physical laws. Numerical values of coefficient of drag force and Nusselt number are also tabulated for different parameters. It is observed that tangential velocity (function of rotation parameter) is increasing for both CNTs. Further, the incremental values of thermal stratification parameter cause the decrease in fluid temperature parameter.

scholarly journals Magnetic field dependent viscous fluid-flow between squeezing plates with homogeneous and heterogeneous reactions

2021 ◽  
Vol 25 (Spec. issue 2) ◽  
pp. 423-431
Author(s):  
Wajid Jan ◽  
Muhammad Farooq ◽  
Jamel Baili ◽  
Rehan Ali Shah ◽  
Aamir Khan ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Viscous Fluid ◽  
Tangential Velocity ◽  
Magnetic Reynolds Number ◽  
Heterogeneous Reactions ◽  
Navier Stokes ◽  
Fluid Temperature ◽  
Field Equations ◽  
Homogeneous And Heterogeneous Reactions ◽  
Field Dependent

The impacts of magnetic field dependent viscous fluid is explored between squeezing plates in the presence of homogeneous and heterogeneous reactions. The unsteady constitutive equations of heat and mass transfers, modified Navier-Stokes, magnetic field and homogeneous and heterogeneous reactions are coupled as an system of ODE. The appropriate solutions are established for the vertical and axial induced magnetic field equations for the transformed and momentum as well as for the MHD pressure and torque exerted on the upper plate, and are in details. In the case of a smooth plate, the self-similar equation with acceptable starting assumptions and auxiliary parameters is solved by utilising a homotopy analytics method, to generate an algorithm with fast and guaranteed convergence. By comparing homotopy analytics method solutions with BVP4c numerical solver packaging, the validity and correctness of the homotopy analytics method findings are demonstrated. Magnetic Reynolds number have been shown to cause to decrease the distribution of magnetic field, fluid temperature, axial and tangential velocity. The magnetic field also has vertical and axial components with increasing viscosity. The applications of the investigation include car magneto-rheological shock absorbers, modern aircraft landing gear systems, procedures for heating or cooling, biological sensor systems, and bio-prothesis, etc.

Ohmic and viscous dissipation effects on micropolar non-Newtonian nanofluid Al2O3 flow through a non-Darcy porous media

2022 ◽  
pp. 1-13
Author(s):  
Nabil T. Eldabe ◽  
Mohamed Y. Abou zeid ◽  
Sami M. El Shabouri ◽  
Tarek N. Salama ◽  
Aya M. Ismael
Keyword(s):  
Magnetic Field ◽  
Heat Source ◽  
Numerical Solutions ◽  
Tangential Velocity ◽  
Darcy Number ◽  
Physical Parameters ◽  
Fluid Temperature ◽  
High Concentration ◽  
Ohmic Dissipation ◽  
Similarity Transformations

Inclined uniform magnetic field and mixed convention effects on micropolar non-Newtonian nanofluid Al2O3 flow with heat transfer are studied. The heat source, both viscous and ohmic dissipation and temperature micropolarity properties are considered. We transformed our system of non-linear partial differential equations into ordinary equations by using suitable similarity transformations. These equations are solved by making use of Rung–Kutta–Merson method in a shooting and matching technique. The numerical solutions of the tangential velocity, microtation velocity, temperature and nanoparticle concentration are obtained as functions of the physical parameters of the problem. Moreover, we discussed the effects of these parameters on the numerical solutions and depicted graphically. It is obvious that these parameters control the fluid flow. It is noticed that the tangential velocity magnifies with an increase in the value of Darcy number. Meanwhile, the value of the tangential velocity reduces with the elevation in the value of the magnetic field parameter. On the other hand, the elevation in the value of Brownian motion parameter leads to a reduction in the value of fluid temperature. Furthermore, increasing in the value of heat source parameter makes an enhancement in the value of nanoparticles concentration. The current study has many accomplishments in several scientific areas like medical industry, medicine, and others. Therefore, it represents the depiction of gas or liquid motion over a surface. When particles are moving from areas of high concentration to areas of low concentration.

scholarly journals Effects of the rotation number on flow and heat transfer in contra-rotating disk cavity with superposed flow

2019 ◽  
Vol 11 (10) ◽  
pp. 168781401988104 ◽  
Author(s):  
Shu-xian Chen ◽  
Jing-zhou Zhang
Keyword(s):  
Heat Transfer ◽  
Flow Structure ◽  
Rotation Number ◽  
Tangential Velocity ◽  
Inertial Force ◽  
Rotating Disk ◽  
Rotating Disks ◽  
Radial Temperature ◽  
Disk Rotation ◽  
Type Flow

The turbulent fluid flow and convective heat transfer in counter-rotating disk cavity with central axial air inflow and radial air outflow are numerically studied based on the finite volume method. Efforts are focused upon the influence of the rotation number Rt on the flow structure, cooling performance, sealing effect, and surface tangential friction characteristics in the cavity. The stagnation point where the radial outward flow along the upstream disk driven by the rotation force meets the radial outward flow along downstream disk driven by the combination of rotation force and inflow inertial force moves from upstream disk wall to the shroud with increasing Rt. At the Rt far smaller than 1, the fluids in the core region between two disks rotate with the upstream disk like a rigid body, and the tangential velocity of the rotating core decreases with the increase of the disk cavity radius, which is different from the Batchelor-type flow. At the Rt larger than 1, the fluids on the upstream disk side rotate like the Batchelor-type flow, while the sandwich rotation disappears in the fluid on the downstream disk side. The temperature on the upstream disk wall increases and then decreases with increasing values of Rt, and the critical value of Rt for the change of temperature variation is assessed to be at about Rt = 0.69. The temperature and radial temperature gradient of the downstream disk wall decrease with increasing Rt. With increasing Rt by increasing the disk rotation rate, the pressures near the downstream disk decrease, while the frictional moments on rotating disks increase. Due to the effect of flow structure, the frictional moment on the upstream disk is smaller than that on the downstream disk.

An Integral Method for Turbulent Boundary Layers on Rotating Disks

1993 ◽  
Vol 115 (4) ◽  
pp. 614-619 ◽  
Author(s):  
S. Abrahamson ◽  
S. Lonnes
Keyword(s):  
Boundary Layer ◽  
Boundary Layers ◽  
Integral Method ◽  
Radial Profile ◽  
Tangential Velocity ◽  
Turbulent Boundary Layers ◽  
Similarity Solutions ◽  
Layer Growth ◽  
Rotating Disks ◽  
Boundary Layer Growth

An integral method for computing turbulent boundary layers on rotating disks has been developed using a power law profile for the tangential velocity and a new model for the radial profile. A similarity solution results from the formulation. Radial transport, boundary layer growth, and drag on the disk were computed for the case of a forced vortex frees tream flow. The results were compared to previous similarity solutions. The method was extended to a Rankine vortex freestream flow. Differential equations for boundary layer parameters were developed and solved for different Reynolds numbers to look at the net entrainment, boundary layer growth, and drag on the disk.

Irreversibility and Thermo-Diffusion Effects on Unsteady Chemically Reactive Slip Flow Between Two Rotating Disks

2019 ◽  
Vol 141 (10) ◽  
Author(s):  
M. Ijaz Khan ◽  
Sumaira Qayyum ◽  
T. Hayat ◽  
M. Waqas ◽  
A. Alsaedi
Keyword(s):  
Slip Flow ◽  
Velocity Slip ◽  
Convergent Series ◽  
Heterogeneous Reactions ◽  
Bejan Number ◽  
Nonlinear Thermal Radiation ◽  
Slip Parameter ◽  
Rotating Disks ◽  
Diffusion Parameters ◽  
Homotopy Analysis

Abstract This paper aims to investigate the entropy generation in slip flow due to double rotating disks. Heat equation is formulated by considering effects of viscous dissipation, Joule heating and nonlinear thermal radiation. Brownian motion and thermophoresis effects of nanofluid are also discussed. Applied magnetic field is considered to be time dependent. Homogeneous–heterogeneous reactions are also studied. Von Karman transformations are used. Homotopy analysis method is implemented on system of equations for convergent series solutions. Influence of various flow parameters on entropy, Bejan number, velocity, temperature, Nusselt number, and skin friction is discussed through graphs and tables. Axial velocity decays for higher nonlinear mixed convection variable of temperature and velocity slip parameter. Temperature rises for larger thermal slip parameter and thermophoresis parameter. Entropy and Bejan number are increasing for higher estimation of homogeneous reaction parameter and diffusion parameters.

Velocity and thermal slip effects on MHD third order blood flow in an irregular channel though a porous medium with homogeneous/ heterogeneous reactions

2017 ◽  
Vol 6 (3) ◽  
Author(s):  
M. Gnaneswara Reddy
Keyword(s):  
Porous Medium ◽  
Thermal Radiation ◽  
Fluid Velocity ◽  
Maximum Velocity ◽  
Heterogeneous Reactions ◽  
Fluid Temperature ◽  
Third Order ◽  
Slip Effects ◽  
Channel Configuration ◽  
Core Part

AbstractThis communication presents the transportation of third order hydromagnetic fluid with thermal radiation by peristalsis through an irregular channel configuration filled a porous medium under the low Reynolds number and large wavelength approximations. Joule heating, Hall current and homogeneous-heterogeneous reactions effects are considered in the energy and species equations. The Second-order velocity and energy slip restrictions are invoked. Final dimensionless governing transport equations along the boundary restrictions are resolved numerically with the help of NDsolve in Mathematica package. Impact of involved sundry parameters on the non-dimensional axial velocity, fluid temperature and concentration characteristics have been analyzed via plots and tables. It is manifest that an increasing porosity parameter leads to maximum velocity in the core part of the channel. Fluid velocity boosts near the walls of the channel where as the reverse effect in the central part of the channel for higher values of first order slip. Larger values of thermal radiation parameter

Inward Flow Between Stationary and Rotating Disks

2014 ◽  
Vol 136 (10) ◽  
Author(s):  
Achhaibar Singh
Keyword(s):  
Laminar Flow ◽  
Flow Field ◽  
Velocity Distribution ◽  
Stokes Equations ◽  
Tangential Velocity ◽  
Rotating Disk ◽  
Reynolds Numbers ◽  
Navier Stokes ◽  
Rotating Disks ◽  
Navier Stokes Equations

The present study predicts the flow field and the pressure distribution for a laminar flow in the gap between a stationary and a rotating disk. The fluid enters through the peripheral gap between two concentric disks and converges to the center where it discharges axially through a hole in one of the disks. Closed form expressions have been derived by simplifying the Navier– Stokes equations. The expressions predict the backflow near the rotating disk due to the effect of centrifugal force. A convection effect has been observed in the tangential velocity distribution at high throughflow Reynolds numbers.

Prediction of Fluid Temperatures From Measurements of Outside Wall Temperatures in Pipes

1994 ◽  
Vol 116 (2) ◽  
pp. 179-187 ◽  
Author(s):  
M. Guyette
Keyword(s):  
Temperature Measurement ◽  
Wall Temperature ◽  
Industrial Application ◽  
Thermal Stratification ◽  
Transfer Functions ◽  
Fluid Temperature ◽  
Convolution Integral ◽  
Thermal Transients ◽  
Points Of Interest ◽  
Piping Systems

The monitoring of the fatigue induced by thermal transients in thick-walled structures becomes more and more currently performed, mainly on equipment the failure of which could present severe implications on the environment. The easiest way of performing this monitoring is by use of Green’s functions in a convolution integral of the measured fluid temperatures to assess the stresses at the points of interest. Numerous cases, however, exist where the fluid temperatures are not available and only an outside wall temperature measurement is feasible. This paper describes the development and the industrial application of the so-called “inverse” transfer functions to predict the evolution of the fluid temperature from measurements of the metal temperature either at the outside or in the wall of the considered equipment. Some applications are shown for the particular case of the thermal stratification in piping systems.

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