Study on buoyancy and surface tension driven convection in nanofluid

Abstract

This thesis presents a detail study of linear and non-linear analysis of buoyancy and surface tension driven convection in nanofluid. The linear Rayleigh-Bénard / Rayleigh- Bénard Marangoni convection in nanofluids in the presence of external constraints like magnetic field, rotation and newlineinternal heat generation is investigated. The effect of temperature and volumetric concentration modulation of nanoparticles at the boundary and gravity modulation are studied on the onset of Rayleigh- Bénard newlineconvection. The obtained results are discussed qualitatively and presented newlinegraphically. The problem discussed have important applications in the field of oceanography, geophysics, nuclear fuel, astrophysics, geothermal reservoirs, engineering and space situations with g-jitter connected with gravity simulation studies.Given the rising relevance of nanofluid application, we discuss four newlineproblems in this thesis whose detail summary is presented below: (i) LINEAR AND WEAKLY NON-LINEAR ANALYSIS OF GRAVITY MODULATION ON THE ONSET OF RAYLEIGH BÉNARD CONVECTION IN NANOFLUID The effect of modulation of gravity or time-periodic body force on newlinethe onset of Rayleigh-Bénard convection in nanofluid is studied using newlinelinear and non-linear analysis. The stability of the fluid layer heated from newlinebelow is analysed by considering time-periodic body acceleration. This newlinehappens generally in the vehicles and satellites associated with studies of newlinemicro gravity simulation. In order to study the effect of gravity modulation newlineon the system stability limit, linear and weakly non-linear analysis is performed. Normal mode technique and perturbation method is applied to study linear stability. The critical Rayleigh number and wave number is newlinecalculated by taking modulation of small amplitude. It is found that the critical thermal Rayleigh number can be increase or decrease by a massive amount depending upon the distribution of nanoparticles.In this thesis we considered bottom heavy distribution of nanoparticles. newline