Study on viscosity of MWCNT dispersed in ethylene glycol at different operating conditions for thermal applications

Abstract

Abstract In recent times the development of nanotechnology has taken place at an unprecedented rate. Nano-fluids are one of the remarkable outcomes of the development of new technologies that can be used to increase the efficiency of thermal systems. Nanofluids, which consist of particles in nanometre size and a base fluid, have been hailed as a superior alternative compared to a common heat transfer fluid like water due to their better thermal properties and having many potential applications in many fields, especially in HVAC, electronic cooling, solar heating and cooling etc., The MWCNT-based nanofluid with water-ethylene glycol as base fluid is prepared by two-step method, the water and ethylene glycol are mixed in the ratio 80:20 and four different concentrations of nanofluids: 0% wt, 0.015% wt, 0.15% wt, 1.5% wt are prepared. Rheology analysis are made by using rheometer with temperature ranging from from 10° C to 50° C with steps of 10° C and shear rate was controlled with shear stress varying from 0-10 N/m2. The base fluid shows the Newtonian behaviour being shifted to Non-Newtonian Behaviour, specifically shear thinning behaviour. Rate of change of shear also changes with change in temperature and change in shear stress results change in viscosity with higher concentration of nanoparticles showing higher viscosity.