Thermal stratification effects on mixed convective Maxwell fluid flow with variable thermal conductivity and homogeneous/heterogeneous reactions

Author(s):  
S. Shah ◽  
S. Hussain ◽  
M. Sagheer
2020 ◽  
Vol 401 ◽  
pp. 148-163 ◽  
Author(s):  
G. Sarojamma ◽  
K. Sreelakshmi ◽  
P. Krishna Jyothi ◽  
P.V. Satya Narayana

In this report, the effects of homogeneous-heterogeneous autocatalytic chemical reaction together with the variable thermal conductivity in the Maxwell fluid flow due to nonlinear surface of variable thickness are investigated. Thermal radiation and heat generation / absorption effects are also incorporated in the analysis. Appropriate scaling analysis is implemented to reduce the mathematical model describing the physics of the problem in to a set of nonlinear differential equations and are subsequently solved computationally. Graphical illustrations indicating the effect of pertinent parameters on momentum, thermal and solutal boundary layers are presented and discussed. The study reveals that velocity distribution shows a decreasing (increasing) tendency for larger values of wall thickness parameter when the velocity power law index is less (greater) than unity. The concentration of the homogeneous bulk fluid with catalyst at the surface decreases with increasing chemical reaction rate parameters.


2020 ◽  
Vol 9 (1) ◽  
pp. 338-351
Author(s):  
Usha Shankar ◽  
N. B. Naduvinamani ◽  
Hussain Basha

AbstractA two-dimensional mathematical model of magnetized unsteady incompressible Williamson fluid flow over a sensor surface with variable thermal conductivity and exterior squeezing with viscous dissipation effect is investigated, numerically. Present flow model is developed based on the considered flow geometry. Effect of Lorentz forces on flow behaviour is described in terms of magnetic field and which is accounted in momentum equation. Influence of variable thermal conductivity on heat transfer is considered in the energy equation. Present investigated problem gives the highly complicated nonlinear, unsteady governing flow equations and which are coupled in nature. Owing to the failure of analytical/direct techniques, the considered physical problem is solved by using Runge-Kutta scheme (RK-4) via similarity transformations approach. Graphs and tables are presented to describe the physical behaviour of various control parameters on flow phenomenon. Temperature boundary layer thickens for the amplifying value of Weissenberg parameter and permeable velocity parameter. Velocity profile decreased for the increasing squeezed flow index and permeable velocity parameter. Increasing magnetic number increases the velocity profile. Magnifying squeezed flow index magnifies the magnitude of Nusselt number. Also, RK-4 efficiently solves the highly complicated nonlinear complex equations that are arising in the fluid flow problems. The present results in this article are significantly matching with the published results in the literature.


2019 ◽  
Vol 29 (8) ◽  
pp. 2977-2992 ◽  
Author(s):  
Muhammad Ijaz Khan ◽  
Sumaira Qayyum ◽  
Tasawar Hayat ◽  
Ahmed Alsaedi

Purpose The purpose of this paper is to analyze the Sutterby fluid flow by a rotating disk with homogeneous-heterogeneous reactions. Inspection of heat transfer is through Cattaneo–Christov model. Stratification effect is also considered. Design/methodology/approach Nonlinear equations are solved by the homotopy technique. Findings Sutterby fluid flow by rotating disk is not considered yet. Here the authors intend to analyze it with Cattaneo–Christov heat flux and homogeneous-heterogeneous reactions. Thermal stratification is also taken into consideration. Originality/value No such work is yet done in the literature.


Author(s):  
T. Hayat ◽  
S.A. Shehzad ◽  
A. Alsaedi

Purpose – The purpose of this paper is to investigate the three-dimensional flow of Maxwell fluid with variable thermal conductivity in presence of heat source/sink. Design/methodology/approach – Similarity transformations are utilized to reduce the nonlinear partial differential equations into ordinary differential equations. The governing nonlinear problems are solved by homotopy analysis method. Findings – The paper found that the velocities decrease while temperature increases for higher Hartman number. It is also seen that the thermal boundary layer thickness and temperature are increased with an increase in variable thermal conductivity parameter and heat source/sink parameter. Practical implications – Heat transfer analysis with heat source/sink has pivotal role in many industrial applications like cooling of an infinite metallic plate in a cooling bath, drawing of plastic films, nuclear plants, gas turbines, various propulsion devices for missiles, space vehicles and processes occurring at high temperatures. Originality/value – This study discusses the magnetohydrodynamic three-dimensional flow of Maxwell fluid with variable thermal conductivity and heat source/sink. No such analysis exists in the literature yet.


Sign in / Sign up

Export Citation Format

Share Document