Experimental investigation of the effect of diameter of nanoparticles and temperature on thermal conductivity of Fe-water nanofluid in low concentrations and developing a new model based on experimental data

Abstract

In this investigation, the effect of parameter such as diameter of nanoparticle, temperature of nanofluid and solid volume fraction on thermal conductivity of Fe-water nanofluid has been experimentally evaluated. Then experimental obtained results compare with values obtained from classic models such as H-C and Yu and Choi. A new model is proposed to estimated thermal conductivity based on experimental data. Proposed model is depends on diameter of nanoparticles, temperature of nanofluid and solid volume fraction. Iron nanoparticle in 3 different diameters of 35-45, 65-75 and 95-105 nm are dispersed in deionized water in solid concentration of 0.0313%, 0.0625%, 0.125%, 0.25%, 0.5% and 1%. The thermal conductivity of nanofluid in low concentration and aforementioned different diameter , at various temperature like 27, 35, 45 and 55oC are obtained. In current study, thermal conductivity of nanofluid measured with KD2 thermal analyzer instrument with transient hot wire method. The results show that with increasing temperature and decreasing diameter of nanoparticles, thermal conductivity of nanofluid increases. Also obtained experimental data, especially in high temperature and small diameter of nanoparticles don’t have a good agreement with classical thermal conductivity models. Proposed model with maximum margin of deviation of 2%, has a predictive capability the thermal conductivity based on basic parameters such as volume fraction, temperature and the diameter of the nanoparticles.

Keywords

• thermal conductivity
• diameter of nano particles
• temperature
• solid volume fraction
• nanofluid