Experimental study of thermal conductivity in a hybrid nanofluid (MWCNT and SiO2) in the base fluids of ethylene glycol and water and presentation of a new experimental Correlation

This experimental study investigates the thermal properties and conductivity of a hybrid nanofluid composed of 89% SiO2 and 11% MWCNT in a mixture of 45% ethylene glycol and 55% water. The nanofluid was prepared using a two-step method, and its thermal conductivity was measured across various volume fractions (ranging from 0.1% to 1.45%) and temperatures (from 26.7°C to 50°C) using a KD2 Pro device. The results indicated a 25.1% increase at a volume fraction of 1.45% and a temperature of 50°C. By employing the response surface method, a 5th-degree polynomial equation accurately describes the complex interaction between temperature and volume fraction (R2=0.9996). The model's high accuracy is demonstrated by a Response surface method margin of deviation ranging from 0.238% to 0.355%.