Improved heat transfer of the engine oil by changing it to hybrid nanofluid: Adding hybrid nano-powders

Abstract

In this study many experimental measurements were conducted to examine the efficacy of loading MWCNT-TiO2 into SAE 20 W-40 on thermal conductivity (k). Through applying FESEM and XRD tests, molecular structures of nanoparticle were inspected and using two-step method, nanofluid samples at 0.1, 0.2, 0.4 and 0.8 vol% were prepared. After passing DLS and zeta potential tests, kMWCNT-TiO2/SAE 20W-40 was measured using KD2 Pro at 20–70°C and 0.1–0.8 vol%. Based on results, it was observed that kMWCNT-TiO2/SAE 20W-40 was higher than kSAE 20W-40 and therefore inserting MWCNT and TiO2 into 20 W-40 has a positive effect on thermal conductivity up to 24.42%. Therefore, the number of dispersed nanoparticles has a considerable effect on kSAE 20W-40 so that at 0.1 and 0.8 vol%, it was improved by 3% and 24.42%, respectively. Although kSAE 20W-40 declines by 5.75% with increasing temperature from 20 to 70°C.