Permittivity of (40 nm and 80 nm) alumina nanofluids in ethylene glycol at different temperatures

This article studies the effective permittivity of alumina nanofluids (aluminium oxide) in ethylene glycol. Two nanoparticle sizes (40 nm and 80 nm) were considered measurements carried out at various concentrations (up to 2% volume) six different temperatures (from 298.15 K 348.15 K). An empirical equation is proposed that allows obtain value any concentration or temperature studied ranges. The influence volume fraction, size on relative shown. When compared previous published values for water, current results show base fluid. enhancement was calculated, its behaviour analysed. Smaller sized particles have highest enhancement. Theoretical models study are applied. poor predictions classical attributed positive change mixing these nanofluids. contributions from glycol nanoparticles separated two distinct terms variable index equation. calculated this points main responsible unusual increment colloids.