ISSN: 2180-1053 Vol. 10 No.1 January – June 2018 1 ENTROPY GENERATION OF PSEUDO-PLASTIC NON- NEWTONIAN NANOFLUIDS IN CIRCULAR DUCT UNDER CONSTANT WALL TEMPERATURE A. Falahat 1 , M. Shabani 2* , M. R. Saffarian 3 1 Department of Mechanical Engineering, Shahid Chamran University of Ahvaz, Iran 2 Production technology research institute (ACECR), Ahvaz, Iran 3 Department of Mechanical Engineering, Shahid Chamran University of Ahvaz, Iran ABSTRACT In this paper the second law analysis of thermodynamic irreversibilities in pseudo-plastic non-Newtonian nanofluids through a circular duct under uniform wall temperature thermal boundary have been carried out for laminar flow condition. This nanofluid consists of sodium carboxymethyl cellulose (CMC)–water and two different types of nanoparticles; namely, CuO and Al2O3. Entropy generation is obtained for various Power law number, various volume concentration of nanoparticles, various dimensionless temperature and various Reynolds number. It is found that with the decreasing Power law number and duct length values, total entropy generation at fixed Reynolds number decreases and with increasing wall temperature values, total entropy generation increases, also entropy generation decreases with increasing volume concentration of nanoparticles. KEYWORDS: Entropy generation; Non –Newtonian fluid; Power law number; Laminar flow. 1.0 INTRODUCTION Improvement of convective heat transfer is very important for many thermo-fluid systems. The heat convection can passively be enhanced by fluid thermo physical properties. One way of improving the thermal conductivities of fluids is to suspend small solid particles in the fluid. Pak and Cho (1998) presented an experimental investigation of the convective turbulent heat transfer characteristics of Al2O3 nanofluids. The heat transfer for the nanofluids increases with the increase of volume concentration and Reynolds number. Masuda et al. (1993) showed that the viscosity and the thermal conductivity of liquids are changed by dispersing very-fine particles of some nanoparticles like Al2O3, SiO2 and TiO2 . *Corresponding author e-mail: M-shabani@phdstu.scu.ac.ir brought to you by CORE View metadata, citation and similar papers at core.ac.uk provided by Universiti Teknikal Malaysia Melaka: UTeM Open Journal System