Experimental Study On The Thermophysical Properties Of Self-Rewetting Fluid/Nanofluid

Thermodynamic and transport properties of fluids are all thermophysical properties. The thermodynamic properties include PVT property, saturated vapor pressure, critical parameters, saturated vapor and liquid densities, specific heat capacity, surface tension, speed of sound, and vapor-liquid-equilibrium (VLE) for mixtures. The transport properties include viscosity, thermal conductivity, thermal diffusivity, etc. This paper summerized the measure methods for thermophysical properties of liquids, including majorly the viscosity, thermal conductivity, specific heat capacity, and surface tension, with the most recent progress in thermophysical properties of several self-rewetting fluids.The surface tension gradient in self-rewetting fluids is different from that of pure fluids. The thermophysical properties of fluids may be changed by inclusion of nanoparticles, with deposition layer potentially formed on the heated surface. In this paper, different working fluids were prepared for further observations. These include the self-rewetting fluids made of aqueous n-butanol solutions in different concentrations, and the self-rewetting nanofluids made of aqueous n-butanol solutions with inclusions of alumina nanoparticles.An experimental apparatus was developed for measuring the thermal conductivity of liquid by the transient double hot-wires method, which is based on the theory of one-dimensional unsteady heat conduction in infinite medium. The testing instrument was verified by measuring the absolute ethyl alcohol. The results show that the home made apparatus is of high reliability and accuracy. The apparatus was then used for measuring the thermal conductivities of several self-rewetting fluids. The variation of thermal conductivity with respective to temperature and composition were obtained and linearized. In addition, the viscosity and the surface tension of several self-rewetting fluids were measured and analyzed.