초록
This paper describes experimental investigations of helium-air exchange flows through parti¬tioned opening and two-opening. Such exchange flows may occur following rupture accident of stand pipe in high temperature gas cooled reactor. A test vessel with the two types of small open¬ing on top of test cylinder is used for experiments. An estimation method of mass increment is developed and applied to measure the exchange flow rate. A technique of flow visualization by Mach-Zehnder interferometer is provided to recognize the exchange flows. In the case of exchange flow through the partitioned opening, flow passages of upward flow of the helium and downward flow of the air within the opening are separated by vertical partition, and the two flows interact out of entrance and exit of the opening. Therefore, an experiment of the exchange flow through two-opening is made to investigate effect of the fluids interaction of the partitioned opening sys¬tem. As a result of comparison of the exchange flow rates between the two types of the opening system, it is found that the exchange flow rate of the two-opening system is larger than that of the partitioned opening system due to absence of the effect of fluids interaction. Finally, the fluids interaction between the upward and downward flows through the partitioned opening is found to be an important factor on the helium-air exchange flow.