周期加熱波状壁を有するチャネル流れの実験的研究

抄録

Flows in a corrugated channel with periodic heating were examined experimentally. The channel was set horizontally, with its both ends being opened to the laboratory. The upper wall was smooth and the lower one corrugated whose amplitudes and wavelength was 0.1h and 6.28h, respectively, where h denotes the channel half-width. The upper wall was kept isothermal at the middle temperature of periodic heating, while the lower one was subjected to a sinusoidal temperature distribution by repetition of heating and cooling. The Rayleigh number based on the peak-to-peak amplitude of periodic heating with the same wavelength as that of the corrugation was Ra ≦ 3000. The phase difference between heating and corrugation was ±π/2. The results showed that pairs of counter rotating rolls accompanied with a meandering stream tube were realized, generating the mean horizontal flow. The direction of net flow was reversed when the heating phase was shifted by 180 degrees. It was also found that net flowrate increases monotonically with the Rayleigh number examined.