Rayleigh-Bénard convection in Casson and Hybrid Nanofluids: An Analytical Investigation

The thermal Rayleigh-Bénard convection (TRBC) in two different fluids namely Casson fluid and hybrid nanofluid is investigated analytically. The stability analysis is performed in both linear and non-linear form. The nanofluid properties like thermal conductivity, viscosity, thermal expansion coefficient and density are considered to be functions of the volume fraction of nanoparticles whereas the same properties of Casson fluid are assumed to be constant. The amount of heat transfer is analyzed in the non-linear analysis using the generalized Lorenz model. The influence of Casson fluid parameter and nanoparticles (single and or binary) which affect the onset of convection is analyzed. It is found that hybrid nanofluid delays the convection and will further enhance the heat transfer rate. Also, the Casson parameter advances the convection while it reduces the heat transfer rate.