Instabilities in Coaxial Rotating Jets

• Published in: Journal of thermal science Vol. 9; no. 4; pp. 322 - 326
• Main Authors: Ivanic, Tanja, Foucault, Eric, Pecheux, Jean, Gilard, Virginie
• Format: Journal Article
• Language: English
• Published: 01.12.2000
• Subjects: 不稳定性
• ISSN: 1003-2169; 1993-033X
• DOI: 10.1007/s11630-000-0071-5

The aim of this study is the characterization of the cylindrical mixing layer resulting layer resulting from the interaction of two coaxial swirling jets.The experimental part of this study was performed in a cylindrical water tunnel,permitting an independent rotation of two coaxial jets.The rotations are generated by means of 2×36 blades localized in two swirling chambers.As expected,the evolution of the main instabiltiy modes presents certain differences compared to the plane-mixing-layer case ,Experimental results obtained by tomography showed the existence of vortex rings and streamwise vortex paris in the near field region.This method also permitted the observation of the evolution and interaction of different modes.PIV velocity measurements realized in the meridian plans and the plans perpendicular to the jet axis show that rotation distrots the typical top-hat axial velocity profile.The transition of the the axial velocity profile from jet-like into wake-like is also observed.