European Journal of Technology and Design , 2015, Vol.(8), Is. 2 Copyright © 2015 by Academic Publishing House Researcher Published in the Russian Federation European Journal of Technology and Design Has been issued since 2013. ISSN: 2308-6505 E-ISSN: 2310-3450 Vol. 8, Is. 2, pp. 52-55, 2015 DOI: 10.13187/ ejtd.2015.8.52 www.ejournal4.com UDC 621 Investigation of Dynamics of Nano Fluid 1 Abbas Salimi Fard 2* Farshad Farahbod 1 Islamic Azad University, Sirjan, Iran Department of Chemical Engineering, Sirjan Branch E-mail: abbas.salimifard@yahoo.com 2 Islamic Azad University, Firoozabad, Fars, Iran Department of Chemical Engineering, Firoozabad branch * E-mail: mf_fche@iauf.ac.ir Abstract Experimental work is held to investigate how nanoparticle affects the hydrodynamic properties of the fluid. Nano zinc oxide particles with different diameters using different time duration with ultrasonic method are produced. Thermal conductivity enhancement, changes in viscosity, heat capacity, shear rate and density of nanofluid are compared with those in water base fluid. Keywords: dynamics, nano fluid, density, viscosity. Introduction In recent years, development in the miniaturization technologies results in fabrication of micro-scale electronic devices which is used in various industries such as aerospace and automotive. For maximum performance of these micro devices which is known as MEMS (Micro Electromechanical Systems), the temperatures should be in a certain range. Microchannel [1] as Compact and efficient cooling devices have been developed for the thermal control of MEMS. Utilizing nanofluid as working fluid could improve the cooling and heating performance. Because of more stable nature of nanofluid compared with its pioneer generation (including micro and millimeter particles) and exceptional thermal conductivity of nanoparticles, it could considerably enhance the convective heat transfer coefficient in microchannel. During the last decade, many studies on convective heat transfer with nanofluids have been considered [2-6]. Pak and Cho [2] revealed that the heat transfer coefficients of the nanofluids increase with increasing the volume fraction of nanoparticles and the Reynolds number. Mirmasoumi and Behzadmehr [7] studied the laminar mixed convection of an Al2O3/water nanofluid in a horizontal tube numerically using a two-phase mixture model. They showed that the nanoparticle concentration did not have significant effects on the hydrodynamics parameters, but its effects on the thermal parameters were important for the fully developed region. Izadi et al. [8] considered the laminar forced convection of an Al2O3 /water nanofluid flowing in an annulus. Their results indicate that the friction coefficient depends on the nanoparticle concentration when the order of magnitude of heating energy is much higher than the momentum energy. Thermal transport of nanofluid flow in microchannels has also attracted a few investigators [9-15] due to its promising applications. In a 52