The results of flow experiments performed in a cylinder array designed to mimica Next Generation Nuclear Plant lower plenum design are presented. Pressure drop and velocity field measurements are made. Based on these measurements, five regimes of behavior are identified that are found to depend on Reynolds number. It is found that the recirculation region behind the cylinders is shorter than that of half cylinders placed on the wall representing the symmetry plane. 德國(guó)LaVision PIV/PLIF粒子成像測(cè)速場(chǎng)儀 Imager SX PIV相機(jī) 用于粒子成像測(cè)速(PIV)的熒光示蹤粒子