Passive cooling containment system (PCCS) is a critical component of the passive safety system in the AP1000 type design. The free falling water film spreading on the outer surface of containment helps to keep the inside temperature and pressure under safety limits. An experiment is setup to study the flow characteristics of the free falling water film on large steel plates with no heat transfer, which are 5 meters in length and 1.2 meter in width, and the plate can be tilted from perpendicular to nearly parallel to the ground. The water inlet can be a dam-type baffle or a series of Ⅴ-shape grooves on the baffle. The water overflows the baffle or the grooves on the baffle, and then spreads and flow down the plate. The local film thickness, wave velocity and water coverage rate are measured or estimated under different flow rate up to 2Kg/s, various water inlet setups, and tilt angles. The results are correlated to Reynolds number and discussed.
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