Flow structure behind a honeycomb disk were studied using POD based on PIV data.

The recirculation zone of honeycomb disk was much smaller both in length and in width.

The honeycomb disk drastically decreased the velocity deficit, the rate of velocity recovery.

RSB model could be detected by the first two POD models in the instantaneous wake.

Due to penetration of the honeycomb, POD modes 4 is obviously different.