International Journal of Scientific Research and Engineering Development

Nanofluids have emerged as promising heat transfer media because of their enhanced thermophysical properties compared with conventional working fluids. Among the various nanoparticles investigated for thermal applications, copper and graphene have attracted significant attention owing to their excellent thermal characteristics. The present study provides a theoretical comparison of the thermophysical properties of copperwater (Cu-W) and graphene-water (Gr-W) nanofluids over a nanoparticle mass concentration range of 0-5%. Density, thermal conductivity, specific heat, and dynamic viscosity were evaluated using established theoretical models. The calculated results reveal that thermal conductivity increases continuously with nanoparticle concentration for both nanofluids, while graphene-water consistently exhibits slightly higher thermal conductivity than copper-water. The density of Cu-W nanofluids increases significantly with concentration because of the higher density of copper nanoparticles, whereas Gr-W nanofluids demonstrate only a moderate increase. The specific heat decreases for both nanofluids with increasing concentration; however, graphene-water retains comparatively higher values throughout the investigated range. The adopted viscosity model predicts identical viscosity variations for both nanofluids as a function of concentration. Based on the theoretical analysis, graphene-water nanofluids demonstrate more favorable thermophysical characteristics for advanced heat transfer applications owing to their superior thermal conductivity combined with lower density. The findings of the present work provide useful guidance for selecting suitable nanofluids for thermal management systems and heat exchanger applications.

Murli Mukati, Dr.Govind Maheshwari,"Comparative Evaluation of Thermophysical Properties of Copper-Water and Graphene-Water Nanofluids" International Journal of Scientific Research and Engineering Development, V9(3): Page(2661-2669) May-June 2026. ISSN: 2581-7175. www.ijsred.com. Published by Scientific and Academic Research Publishing.