Abstract
In this report, we show CFD analysis around a two-step collector on a wind tunnel. Although previous study showed that the two-step collector is effective for pulsation suppression on circular wind tunnels, its mechanism should be realized for optimal design. SCRYU/Tetra^[○!R] was adopted for a CFD analysis tool and the turbulence model was DES. The equivalent diameter of nozzle in the analytical model was 4.3 m and the mean velocity of the jet was set to 27.8 m/s. The analytical results show the difference of vortex movement between a two-step collector and a usual collector. The vortex didn't influence inside of the two-step collector, though the vortex run into the usual collector. Furthermore, the velocity fluctuation in the two-step collector was smaller than it in the usual collector. Then the pulsation is suppressed by the two-step collector.
