抄録
This paper concerns the condensation of carbon dioxide and its heat transfer on vertical cylinder in sub critical region. In this region, physical properties show marked temperature and pressure dependence. In particular, as the pressure increases and approaches the critical point, the difference in the properties of liquid and vapor, and surface tension approach zero. Therefore, condensate flow from natural convection decrease and the configuration of condensation differ from that at lower pressures. In this study, the flow regimes were classified into the smooth laminar flow, wavy flow and wavy flow with scattered droplets based on observing condensate flow. And heat transfer is discussed in connection with the flow regime.