Investigation of entropy generation in nanofluid’s axisymmetric stagnation flow over a cylinder with constant wall temperature and uniform surface suction-blowing

Abstract

Dimensionless temperature, Nusselt number and entropy generation in stagnation flow of incompressible nanofluid over an infinite cylinder accompanying uniform suction and blow in steady state have been investigated in this study. Free stream has been steady as well with the initial stream rate of k¯. Dimensional analysis and similarity solution of Navier-stokes and energy equations have been presented. These equations are simplified implementing appropriate transformations introduced in this research. The similarity equations are solved where the cylinder’s wall is under constant Temperature. All these solutions are acceptable for Reynolds numbers Re=k¯a2/2υf of 0.1–1000, various dimensionless surface diffusion S=Uo/k¯a and specific volume fractions of nano particles where a is the cylinder radius and υf 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 nano particles volume fraction and surface suction raises heat transfer coefficient and Nusselt number. Also the largest amount of entropy generated is calculated.