抄録
Single phase natural convection in a rectangular loop was experimentally invenstigated. As the results, there was no after effect in the temperature difference between left and right vertical branches and the frequency of temperature oscillation. However, the temperature oscillation patterns are largely influenced by the duration of no heat input. Therefore, in order to investigate the transient effect of the flow in the loop, it is necessary for the loop to rest at least 24 hours. The boundary between the unstable and stable state experimentally determined was slightly different from that obtained from the one-dimensional model.
