International Journal of Engineering Research in Electronics and Communication Engineering

Effect of Chemical Reaction on Convective Instability in a Ferromagnetic Liquid

Author : Dr. Annamma Abraham, Sreelakshmi T K, Dr. Chethan A S, Dr. Jojy Joseph Idicula ¹

Date of Publication :20th April 2017

Abstract: Convective instability in fluids arises due to thermo-mechanical interactions induced by externally applied temperature gradients. The problem of Rayleigh-Benard convection in a chemically reacting ferromagnetic fluid layer permeated by a uniform vertically magnetic field is investigated. A linear stability analysis is performed. The fluid is assumed to be undergoing zero-order exothermic reactions. The horizontal ferromagnetic fluid layer is cooled from the upper boundary while two different thermal boundary conditions are imposed at the lower boundary i.e. isothermal wall and an adiabatic wall. The resulting eigenvalue problems will be solved approximately using a single-term Galerkin method that gives the critical Rayleigh number and the associate wave number at a given Frank-Kamennetskii number. It is shown that the critical Rayleigh number decreases as the value of FK is increased. Thus, chemical reaction in a horizontal ferrofluid layer enhances instability. This is reasonable because chemical reaction leads to non-linear temperature distribution. The onset of convection is delayed in a chemically reacting ferrofluid as compared to the case of a chemically reacting liquid. The problem has relevance in many ferromagnetic fluid applications wherein regulation of thermal convection is called for.

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