LTNE thermoconvective instability in Newtonian rotating layer under magnetic field utilizing nanoparticles

Abstract

In the present framework, the simultaneous effect of rotation, magnetic field, heat source and local thermal non-equilibrium (LTNE) is investigated on a water-based nanofluid layer. A mathematical model depicting LTNE behavior between base fluid and nanoparticles phases along with slip mechanisms, i.e., Brownian motion and thermophoresis is taken into consideration. Both linear and weakly nonlinear analyses have been performed for a given dynamical system. The normal mode technique and Galerkin weighted residual method (GWRM) are employed to find the stationary mode of convection for free–free (FF), rigid–rigid (RR) and rigid–free (RF) boundary conditions in linear stability. In case of nonlinear stability, the minimal truncated Fourier series is implemented and the resulting system of equations is solved using MATLAB built-in ode solver to visualize the streamlines, heatlines and quantify the heat and mass transport. The magnetic field, rotation, interface heat transfer and thermal diffusivity ratio parameters delay the onset of convection in the nanofluid layer, while the modified thermal capacity ratio and heat source advance it. Thus, heat transfer enhancement has been reported with the increment of both modified thermal capacity ratio and heat generation, whereas the opposite trend is noticed for other parameters in nanofluid layer. For Ra > Rac, the isotherms for both fluid and particle phases are flattened near the wall which depicts the increase in the convection in the nanofluid layer. The present investigation of Rayleigh–Benard convection in nanofluids may be useful for providing parameter ranges where the desired instability can be made to manifest depending upon the need for an engineering application.