Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : November 12, 2022 - November 13, 2022
In order to better understand how critically the small surface irregularity affects the formation of thermal convection, natural convection in a horizontal slot with surface corrugation was examined experimentally at Rayleigh number based on the slot half-height below 300. The sinusoidal surface corrugations whose amplitude was 2.5% of the slot full-height and wavenumber was 0.5 - 2 was applied on the bottom surface while upper surface was kept smooth. Both walls were heated uniformly at different temperature. The results showed that surface corrugation promoted the occurrence of thermal convection significantly, that is, a pair of convection rolls whose wavelength was the same as that of corrugation was observed at Rayleigh number much lower than the critical one of smooth slot. Beyond critical Rayleigh number, on the other hand, the Rayleigh-Benard convection dominated the flow regardless of corrugation wavelength examined.
