Abstract Stable colloidal solutions of nanoparticles are termed “nanofluids.” Nanofluids are envisioned for augmenting thermal energy storage (TES), heat management systems, and heat transfer fluids (HTFs). The thermophysical properties of nanofluids (such as density and specific heat capacity) often deviate from the predictions obtained from the classical mixture rule. These discrepancies can be obviated by incorporating the properties of a third phase, termed the “compressed phase,” which arises from the formation of a surface adsorbed phase of the fluid molecules on the nanoparticle. In this study, the magnitude of deviant-density was predicted by leveraging a novel dimensionless parameter, termed the Sen–Banerjee number (SB). SB was utilized for predicting the critical threshold at which the deviant-density is hyper-sensitive to small changes in the mass concentration of the nanoparticles. This model, based on the “nanofin effect (nFE),” was applied for analyses of three representative nanofluid systems. Surprisingly, nanoparticles with a smaller density amplify the deviant-density values. These analyses provide a geometry-independent unified framework (SB) for estimating the deviant-density values and guiding the design of high-performance nanofluids for energy, transport, and thermal management applications.
Sen et al. (Thu,) studied this question.