Theoretical Investigation of Entropy Generation in Axisymmetric Stagnation Point Flow of Nanofluid Impinging on the Cylinder Axes with Constant Wall Heat Flux and Uniform Transpiration

Abstract

Dimensionless temperature, Nusselt number and entropy generation in stagnation flow of incompressible nanofluid impinging on the infinite cylinder with uniform suction and blowing have been presented in this study. Initial stream rate of steady free stream is . Similarity solution of Navier-stokes and energy equations has been presented. These equations are simplified implementing appropriate transformations introduced in this research. The governing equations are solved where the heat flux at the cylinder’s wall is constant. All these solutions are acceptable for Reynolds numbers of 0.1-1000, various dimensionless surface diffusion and specific volume fractions of nanoparticles where a is the cylinder radius and is the kinematic viscosity of the base-fluid. The results show that for all Reynolds numbers, diffusion depth of radial and axial components of velocity field and wall shear stress increases as a result of decline in nano particles volume fraction and growth in surface diffusion. Moreover, increase in nanoparticles volume fraction and surface suction raises heat transfer coefficient and Nusselt number. Also the most entropy generated is calculated.