In this study, we investigated the hydrogen upward flow on locally heated disc in a cylindrical flow channel. The diameter of the heated disc was 60 mm. The hydrogen flow rate Q and nozzle diameter dH were changed for 3 slm < Q < 9 slm and 10 mm < dH < 180 mm, respectively. From the PIV analysis and FFT analysis of the vorticity on the heated disc, it became clear that flow separation occurs at a period of approximately 2.3 seconds at Q = 3 slm and dH = 20 mm even when the diameter of the heated substrate was smaller than that of C. Shekhar et al.. On the other hand, the flow separation was not observed at Q = 3 slm and dH = 10 mm. This suggested that flow separation was not determined solely by the type of gas and the ratio of nozzle diameter to heating substrate diameter, but also could depend on operating conditions such as flow rate and channel height.
WANG et al. (Wed,) studied this question.