Thermal Conductivity Enhancement of Silica Nanofluids for Ultrafast Cooling Applications: Statistical Modeling and Economic Analysis

Abstract

Effectively dispersed spherical metallic or non-metallic nanoparticles at low mass concentrations in water, oil, or ethylene glycol may enhance the thermal conductivity of the mixture over the basefluid values. Focusing on the dilute suspensions of effectively dispersed SiO2 nanoparticles in water, the thermal conductivity of nanofluids was measured and statistical and economic analysis was performed. Stable nanofluids were prepared by dispersing dry SiO2 particles directly in water using sonication. The thermal conductivity of nanofluid with mass concentrations of 0.01 % to 1 % was estimated using a unique ultrasonic velocity measurement technique at various temperatures over 25 °C to 65 °C for every 10 °C rise. Impacts of concentration, temperature, and component materials on thermal conductivity enhancement were obtained. Experimental data are analyzed through statistical method and a simple linear regression model (with R2 > 0.99) of thermal conductivity is presented. Further, pricewise performance of nanofluids is performed to obtain the economic feasibility of SiO2–water nanofluids in heat transfer applications.