A two-dimensional recirculating laminar flow through a T-type extractor of a duct has been visually investigated with the fluorescent dye, aluminum powder and the hydrogen bubble.
Two different duct systems were used to get the flow Reynolds numbers between 50 and 1500. It was found that for Re ≤ 200, the reattachment point does not move and a stationary recirculating bubbles were observed. However, for Re＞500, the bubbles began to fluctuate and be swept downstream.
Qualitatively, this flow visualization experiments exhibited almost the same flow structures predicted by a computational analysis of Chang and Chung.