Abstract
Background: This study investigates the thermal conductivities of the Ag-CuO-tungsten oxide/water ternary hybrid nanofluids (THNFs) with mixing ratios of 20, 45 and 35%, Ag-tungsten oxide/water, Ag-CuO/water, tungsten oxide-CuO/water hybrid nanofluids (HNFs) (with 50% mixing ratio), and Ag/water, CuO/water, and tungsten oxide/water mono nanofluids (MNFs) in a laboratory. Methods: Using the two-step method, the nanofluids (NFs) are fabricated by dispersing nanoparticles (NPs) in base fluids. THNFs are formed in volume fractions phi =0.1-0.4% and MNFs and HNFs are made in phi=0.1 and 0.3%. After ensuring NF stability, thermal conductivity (TC) is measured within T = 20-50 degrees C. The results show that raising temperature increases TC. Moreover, increasing phi increases TC; and increasing temperature has a greater effect in higher phi. The results suggest that the Ag/water MNF in the phi=0.4% and T = 50 degrees C has the highest TC with a 49.7% increase compared to the base fluid. Finally, a mathematical model is proposed for estimating the TC of Ag-CuO-tungsten oxide/ water THNFs.Significant Findings: Comparison of the proposed equation's results with laboratory results shows that the proposed model for the Ag-CuO-tungsten oxide/water THNF was accurate within 20-50 degrees C and phi=0.1-0.4%.