Experimental study of the heat transfer characteristics of supercritical pressure R134a in a horizontal tube

Effects of buoyancy and thermophysical property variations on the flow of supercritical carbon dioxide

“…It was found that the compressibility effect linked to the pressure fluctuation and dilatation of velocity fluctuation could be ignored, while the buoyancy production was significant, due to strong density fluctuations. Chu and Laurien (2016) simulated a horizontal pipe flow of supercritical carbon dioxide, which confirmed the observations made by Tian et al (2019). The wall temperature was again found to be higher at the top due to the secondary flow caused by buoyancy.…”

“…It was found that the buoyancy criteria based on supercritical water is not applicable to organic fluids, thus a new parameter was developed and validated against their own experimental data and those from previous literature. A set of experiments of supercritical R134 flows in horizontal pipes was obtained in Tian et al (2019) to provide heat transfer data and correlations for further studies. A non-uniform circumferential wall temperature distribution was observed in these results, which can be attributed to the effect of buoyancy.…”

Experimental Investigation of Near- and Supercritical Heat Transfer to R125 Flowing in a Horizontal Tube

“…Most of the refrigerant heat transfer measurements on horizontal flows under heating conditions have been performed for R134a. Tian et al [10], [11] did experiments on R134a on tubes with inner diameters (di) of 10.3 and 16 mm. Different criteria to determine the onset of buoyancy effects were evaluated, and a new, more simple one, was proposed.…”

Thermophysical Properties and Supercritical Heat Transfer Characteristics of R515A

“…Supercritical fluids have wide range of industrial applications owing to the substantial impact of their heat transfer characteristics [1][2][3][4][5][6][7][8]. Supercritical fluids, in comparison with conventional fluids, have attracted growing amount of attention because of relatively higher heat transfer rate and lower energy losses [9].…”