摘要:PIV (particle image velocimetry) measurement of the air flow past a counter-swirler 53983 (anticlockwise swirler surrounded by clockwise swirler) is performed. The measurement is focused to an area at the boundary between the inner swirling jet and the outer one rotating oppositely. The Reynolds number Re based on the inner swirler diameter ranged form 1.2·103to 2.1·104. By using band pass filtering the shear layer and vortices in the contact region between counter-swirling jets is highlighted. The shear layer between these regions shortens and decays into vortices as Reynolds number increases.