Development of a new density correlation for carbon-based nanofluids using response surface methodology

Density is among the fundamental thermo-physical characteristics of fluids that are examined prior to carrying out performance analysis of the fluid. In this study, the effect of the design variables on the density of nanofluids was studied using response surface methodology (RSM). The quadratic model produced by RSM was employed to determine the performance factors, i.e., mass concentration and temperature with reasonably good accuracy. Improved experimental correlations were proposed for the density prediction of the carbon-based nanofluids based on the experimental data. Experimentally measured densities of two different nanofluids at the nanoparticle mass concentration of up to 0.1% and the temperature range of 20-40 A degrees C were examined. The improvement in densities compared to the density of base fluid at 20 and 40 A degrees C is approximately 0.15% for 0.1% fraction of MWCNT-COOH nanoparticles. Additionally, the densities of F-GNP nanofluids are increased by 0.056% compared to the density of distilled water. As a final point, the RSM results were compared with the results which got from the empirical data. It was detected that the optimal RSM model is accurate and the absolute maximum deviation measured values from the predicted densities of MWCNT-COOH and F-GNP nanofluids are 0.012 and 0.009%, respectively.