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MHD nanofluid flow with variable physical parameters via thermal radiation: A numerical study
Author(s) -
Govindaraj N.,
Singh A. K.,
Shukla Pankaj
Publication year - 2020
Publication title -
heat transfer
Language(s) - English
Resource type - Journals
eISSN - 2688-4542
pISSN - 2688-4534
DOI - 10.1002/htj.21848
Subject(s) - prandtl number , mechanics , thermophoresis , magnetohydrodynamics , physics , buoyancy , coordinate system , nanofluid , classical mechanics , magnetohydrodynamic drive , grashof number , nonlinear system , reynolds number , nusselt number , mathematics , convection , heat transfer , geometry , magnetic field , turbulence , quantum mechanics
Objective: The objective of the current study is to deal with magnetohydrodynamic (MHD) nanoliquid flow over moving vertical plate with variable Prandtl numbers and viscosities. This analysis also includes the influence of thermal radiation. Quite significant variation in viscosity and Prandtl number in high‐range temperature is observed. Thus, Prandtl number and viscosity are surmised to vary as an inversely proportional linear function of temperature. Problem definition: The MHD nanoliquid flow is considered along with the semi‐infinite plate with the velocity U w toward the x ‐direction, which is also the direction for free‐stream velocity ( U ∞ ) . The geometrical sketch of the physical problem with the coordinate system is shown in Figure 1. The coordinate system has two coordinate axes: the ξ ‐coordinate ( x ) and η ‐coordinate ( y ). They are perpendicular to each other. The mathematical modeling of physical problem has been formulated by incorporating viscous terms into the governing equation related to thermal radiation, buoyant force, Brownian motion, thermophoresis, and magnetic parameter. Methodology: The mathematical modeling of current physical problem consists of highly nonlinear partial differential equations which have been solved numerically using quasilinearization technique along with finite difference method. The present outcome during numerical simulation is outlined in terms of velocity, temperature, and concentration profiles and they are analyzed with suitable physical reasons. Main results: The impact of various parameters on the velocity, temperature, and concentration profiles has been discussed with physical explanation. Velocity profile ( F ) of the fluid enhances and concentration ( ϕ ) reduces with escalating buoyancy parameter ( λ ) . In particular, 13% increment in velocity profile is observed as λ increases by 0.9 scale [ 0.9 → 1.8 ], whereas 17% reduction in concentration profiles is noticed as λ increases by 0.5 scale [ 1.5 → 2.0 ] at other fixed parameters. It is observed that magnetic parameter ( H ) increases the temperature ( θ ) and concentration profiles ( ϕ ) , whereas it works as deduction parameter for velocity profile ( F ) . The increasing value of thermophoresis ( N t ) and Lewis number ( L e ) works as catalyst for velocity, temperature, and concentration profiles. As thermophoresis ( N t ) increases from 0.5 to 2.0, temperature profile approximately increases 65% at other fixed parameters. As Lewis number ( L e ) increases from 0.5 to 4.0, then the temperature increases approximately 75% at other fixed parameters.