Improving the thermal properties of water by adding MWCNTs, cerium oxide, and MgO hybrid nanoparticles at different temperatures and volume fraction of nanoparticles: Experimental investigation

Abstract

This study aimed to investigate the thermal conductivity (TC) of various nanofluid compositions, including water/MWCNT-MgO-cerium oxide ternary hybrid nanofluids (THNFs) with solid volume fractions (SVFs) ranging from 0.1 % to 0.6 %. Additionally, the thermal conductivity of water/MWCNT-cerium oxide, water/MWCNT-MgO, and water/MgO-cerium oxide hybrid nanofluids (HNFs), as well as water/MWCNT, water/cerium oxide, and water/MgO mono nanofluids (MNFs), was measured at SVF=0.1 % and 0.3 %. The experimental temperature was varied between 20, 30, 40, and 50 °C for all samples. The MWCNT, MgO, and cerium oxide nanoparticles (NPs) were suspended in the water base fluid (BF) to create the nanofluids (NFs) in a two-step process. MWCNT NPs are 20–30 nm in size, MgO NPs are 20 nm, and cerium oxide NPs are 10–30 nm in size. DLS and zeta potential experiments, which demonstrate the correct stability of NFs, were used to evaluate the stability of NFs. The KD2-Pro instrument was used to test the samples' TC after making sure they were stable. The data obtained demonstrate a rise in TC with rising SVF and rising temperature. The MWCNT/water MNF exhibits the largest rise in TC in SVF=0.3 %, with a TC increase of 19.16 % at T = 40 °C. It should be noted that the largest increase in TC is 26.09 % compared to the BF for water/MWCNT-MgO-cerium oxide THNF at SVF=0.5 % and T = 40 °C. Finally, a mathematical connection was shown with the comparisons done to estimate the data. The results demonstrate the postulated relationship's high degree of accuracy. © 2024 The Author(s)