Appraising heat transfer enhancement by nanofluid and entropy generation minimization in a micro tall cavity: : Magnetic field and sinusoidal heating effects

Improving heat transfer is a challenging area of research. In recent years, new ideas have continuously emerged on this subject. Microchannels and microcavities have proven better heat transfer efficiency [1-3]. The present study aims to analyze the magnetohydrodynamics (MHD) heat transfer enhancement and entropy generation in a micro open tall cavity filled with nanoliquid under the effects of uniform magnetic field and bottom sinusoidal heating in the slip flow regime. A mesoscopic numerical analysis based on the SRT-BGK lattice Boltzmann numerical method (LBM) is used to resolve the governing equations with boundary conditions special treatment. The slip velocity and the temperature jump conditions are used to incorporate the micro aspect. The flow pattern, heat transfer characteristics and the irreversibility pattern are studied dependently on various dimensionless independent monitoring parameters in a set of ranges, namely: Rayleigh number (Ra) (10²-10⁴), Knudsen number (Kn) (0-0.1) and Hartmann number (Ha) (0-80), nanosuspensions volume fraction Vf (0-0.04%) as well as the magnitude A (0-1) and wave length parameter f of the sinusoidal heating function T(x) =A sin(fx/L), 1≤f=2πL/λ≤9 and λ is the signal wavelength.

I. Introduction

Optimization in engineering is a significant tool for selecting target best fit when the model accounts for several design factors. It helps in determining the minimum, optimum or maximum through a combination of a set of design/input factors. In the design of miniaturized heat exchangers such as micro cavities and micro channels, credible researches are going on to appraise the ultimate effectiveness and certain labors are being done to improve / optimize the thermal heat transfer under the constraint of the heat generation minimization and the ranges of the monitoring parameters describing the flowing fluid, the media configuration and the external contact (surface) forces at boundary conditions and bulk (distance) force. In this respect, design of experiments has been actively researched in recent decades.