Thermal instability arises due to a non-uniform temperature distribution in a plane horizontal fluid layer heated from below. As a result the density at the bottom layer becomes lighter than at the top. The upward heat transfer can be achieved by conduction, but do not necessarily undergo convective motion since viscosity and thermal diffusivity of the fluid try to prevent the convective motion. If the fluid is heated sufficiently large then convective motion arises and fluid develops a regular pattern of convection cells. Recently, there has been significant interest in nanofluids, due to...