Effect of temperature on the effective thermal conductivity of n-tetradecane-based nanofluids containing copper nanoparticles

Nanofluids were prepared by dispersing Cu nanoparticles(~20nm) in n-tetradecane by a two-step method.The effective thermal conductivity was measured for various nanoparticle volume fractions(0.0001-0.02) and temperatures(306.22-452.66 K).The experimental data compares well with the Jang and Choi model.The thermal conductivity enhancement was lower above 391.06 K than for that between306.22 and 360.77 K.The interfacial thermal resistance increased with increasing temperature.The effective thermal conductivity enhancement was greater than that obtained with a more viscous fluid as the base media at 452.66 K because of nanoconvection induced by nanoparticle Brownian motion at high temperature.