Analytical investigation of transient free convection and heat transfer of a hybrid nanofluid between two vertical parallel plates

Abstract

Flow and heat transfer of transient free convection of a hybrid nanofluid between two parallel plates are theoretically investigated. Effects of a magnetic field, thermal radiation, and a heat source or a sink are considered. Laplace transforms are used to solve the dimensionless governing equations. Analytical expressions of velocity and temperature profiles and shear stress and rate of heat transfer are presented. Moreover, the correlations between the parameters and the shear stress and the rate of heat transfer have been derived. Increasing alumina and copper nanoparticle volume fractions reduces the velocity and temperature. However, the converse is seen for increasing heat source or sink parameter. For increasing radiation parameter, the temperature decreases but the velocity first increases. When 5% and 10% alumina nanoparticles are mixed with 5% copper nanoparticle, the heat transfer through the left wall increases about 14% and 30% and that through the right wall enhances about 21% and 44% in comparison to the heat transfer of pure fluid. For 5% and 10% copper nanoparticles with 5% alumina nanoparticle, the corresponding values are 15% and 31% and 22% and 45%, respectively. The heat source or sink intensity also plays an important role in the thermal field and heat transfer.