Activation Energy and Thermal Radiation Aspects in Bioconvection Flow of Rate-Type Nanoparticles Configured by a Stretching/Shrinking Disk

2020 ◽  
Vol 142 (11) ◽  
Author(s):  
Tianping Zhang ◽  
Sami Ullah Khan ◽  
Muhammad Imran ◽  
Iskander Tlili ◽  
Hassan Waqas ◽  
...  

Abstract Recent trends in advanced nanotechnology developed thermal consequences of nanoparticles due to increasing significance in various engineering and thermal extrusion systems. The current continuation analyzes the axisymmetric stagnation point flow of magnetized rate-type nanoparticles configured by a porous stretching/shrinking rotating disk in the presence of motile microorganisms. A famous rate-type polymeric liquid namely Maxwell fluid has been used to examine the rheological consequences. Constitutive expressions based on the Buongiorno nanofluid model are used to examine the thermophoresis and Brownian motion features. With imposing similarity variables proposed by von Karman, the formulated problem is composed into dimensionless form. With the implementation of famous numerical technique bvp4c, the solution of governing flow equations is simulated. Graphical significance for each physical parameter is interpolated with relevant physical aspects. The variation in local Nusselt number, local Sherwood number, and motile density number corresponding to engineering parameters is numerically iterated and expressed in a tabular form. The study revealed that radial direction velocity component decreases by increasing the Deborah number and buoyancy ratio parameter. An enhanced temperature distribution for both stretching and shrinking cases has been noted by increasing the Biot number and thermophoresis parameter. A lower motile microorganisms distributed is noted due to the involvement of motile diffusivity.

2016 ◽  
Vol 12 (2) ◽  
pp. 345-361 ◽  
Author(s):  
Najeeb Alam Khan ◽  
Sidra Khan ◽  
Fatima Riaz

Purpose – The purpose of this paper is to study the three dimensional, steady and incompressible flow of non-Newtonian rate type Maxwell fluid, for stagnation point flow toward an off-centered rotating disk. Design/methodology/approach – The governing partial differential equations are transformed to a system of non-linear ordinary differential equations by conventional similarity transformations. The non-perturbation technique, homotopy analysis method (HAM) is employed for the computation of solutions. And, the solution is computed by using the well-known software Mathematica 10. Findings – The effects of rotational parameter and Deborah number on radial, azimuthal and induced velocity functions are investigated. The results are presented in graphical form. The convergence control parameter is also plotted for velocity profiles. The comparison with the previous results is also tabulated. The skin friction coefficients are also computed for different values of Deborah number. Originality/value – This paper studies the effect of rotation and Deborah number on off-centered rotating disk has been observed and presented graphically.


2019 ◽  
Vol 36 (2) ◽  
pp. 167-190 ◽  
Author(s):  
Muhammad Asif Javed ◽  
Nasir Ali ◽  
Sabeen Arshad

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.


2019 ◽  
Vol 81 (4) ◽  
pp. 501-512
Author(s):  
I.A. Zhurba Eremeeva ◽  
D. Scerrato ◽  
C. Cardillo ◽  
A. Tran

Nowadays, the emergence of new lubricants requires an enhancement of the rheological models and methods used for solution of corresponding initial boundary-value problems. In particular, models that take into account viscoelastic properties are of great interest. In the present paper we consider the mathematical model of nonstationary motion of a viscoelastic fluid in roller bearings. We used the Maxwell fluid model for the modeling of fluid properties. The viscoelastic properties are exhibited by many lubricants that use polymer additives. In addition, viscoelastic properties can be essential at high fluid speeds. Also, viscoelastic properties can be significant in the case of thin gaps. Maxwell's model is one of the most common models of viscoelastic materials. It combines the relative simplicity of constitutive equations with the ability to describe a stress relaxation. In addition, viscoelastic fluids also allow us to describe some effects that are missing in the case of viscous fluid. An example it is worth to mention the Weissenberg effect and a number of others. In particular, such effects can be used to increase the efficiency of the film carrier in the sliding bearings. Here we introduced characteristic assumptions on the form of the flow, allowing to significantly simplify the solution of the problem. We consider so-called self-similar solutions, which allows us to get a solution in an analytical form. As a result these assumptions, the formulae for pressure and friction forces are derived. Their dependency on time and Deborah number is analyzed. The limiting values of the flow characteristics were obtained. The latter can be used for steady state of the flow regime. Differences from the case of Newtonian fluid are discussed. It is shown that viscoelastic properties are most evident at the initial stage of flow, when the effects of non-stationarity are most important.


2000 ◽  
Author(s):  
H. S. Udaykumar ◽  
R. Mittal ◽  
P. Rampunggoon

Abstract We present a numerical technique for computing flowfields around moving solid boundaries immersed in flows on fixed meshes. The mixed Eulerian-Lagrangian framework treats the immersed boundaries as sharp interfaces and a finite volume formulation for the flow solver allows boundary conditions at the moving surfaces to be exactly applied. A second-order accurate spatial and temporal discretization is employed with a fractional-step scheme for solving the flow equations. A multigrid accelerator for the pressure Poisson equations has been developed to apply in the presence of multiple embedded solid regions on the mesh. We validate the numerics by comparing against experimental and numerical results on two problems: 1) The flow in a channel with a moving indentation in one wall and 2) The dynamics of vortex shedding from a cylinder oscillating in the free-stream.


1993 ◽  
Vol 74 (1) ◽  
pp. 40-44 ◽  
Author(s):  
C. F. Chan Man Fong ◽  
D. De Kee ◽  
B. Marcos

2018 ◽  
Vol 7 (4.10) ◽  
pp. 233
Author(s):  
K. Gangadhar ◽  
K. V. Ramana ◽  
B. Rushi Kumar

The influence of the heat transfer within a boundary layer flow and magneto hydro dynamic slip flow of a Maxwell fluid over a stretching cylinder is analyzed and discussed in the present article. The effects of viscous dissipation and thermal jump are assumed. The procedure of heat transfer through hypothesis of Cattaneo-Christov heat flux is considered. We converted non-linear partial differential equations for mass, momentum and energy into a system of coupled highly non linear ordinary differential equations with proper boundary conditions by the help of suitable similarity transformations. The succeeding ordinary differential equations are solved by using Spectral relaxation technique. The solution is obtained in zero curvature parameter as well as non-zero curvature parameter.  i.e. for flow above a flat plate and flow above a cylinder. The flow and heat transfer attributes are witnessed to be encouraged in an elaborate mode by Prandtl number, thermal jump parameter, thermal relaxation parameter, Deborah number, slip velocity parameter, Eckert number and the magnetic parameter. Our findings reveal that one of the possible ways to decrease the Deborah number by boosting fluid velocity. It is also perceived that in the case of flow over a stretching cylinder, the momentum boundary layer thickness and the velocity of the fluid increases. Furthermore, an increase in slip velocity factor reduces the magnitude of skin friction.  


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
M. Qasim ◽  
S. Noreen

This investigation deals with the Falkner-Skan flow of a Maxwell fluid in the presence of nonuniform applied magnetic fi…eld with heat transfer. Governing problems of flow and heat transfer are solved analytically by employing the homotopy analysis method (HAM). Effects of the involved parameters, namely, the Deborah number, Hartman number, and the Prandtl number, are examined carefully. A comparative study is made with the known numerical solution in a limiting sense and an excellent agreement is noted.


2018 ◽  
Vol 387 ◽  
pp. 145-156 ◽  
Author(s):  
Sure Geethan Kumar ◽  
S. Vijaya Kumar Varma ◽  
Putta Durga Prasad ◽  
Chakravarthula S.K. Raju ◽  
Oluwole Daniel Makinde ◽  
...  

In this study, we numerically investigate the hydromagnetic three dimensional flow of a radiating Maxwell fluid over a stretching sheet embedded in a porous medium with heat source/sink, first ordered chemical reaction and Soret effect. The corresponding boundary layer equations are reduced into set of non-linear ordinary differential equations by means of similarity transformations. The resulting coupled non-linear equations are solved numerically by employing boundary value problem default solver in MATLAB bvp4c package. The obtained results are presented and discussed through graphs and tables. It is noticed that the Deborah number reduces the velocity fields and improves the temperature and concentration fields. Nomenclature


Sign in / Sign up

Export Citation Format

Share Document