Jet column modes in both a plane jet and a passively modified plane jet subject to acoustic excitation

• Published in: Experiments in fluids Vol. 35; no. 3; pp. 278 - 287
• Main Authors: Olsen, J. F., Rajagopalan, S., Antonia, R. A.
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01.09.2003; Berlin
• Subjects: Acoustic excitation; Coherence; Columns (structural); Exact sciences and technology; Excitation; Fluid dynamics; Fundamental areas of phenomenology (including applications); Instrumentation for fluid dynamics; Jets; Nozzles; Physics; Planes; Strouhal number; Turbulence control; Turbulent flows, convection, and heat transfer; Test facilities; Flow visualization; Jets; Control systems; Experimental study; Velocity measurement; Turbulence structure; Mixing layer; Plane geometry; Acoustic waves; Periodic perturbation
• ISSN: 0723-4864; 1432-1114
• DOI: 10.1007/s00348-003-0663-4

Use is made of acoustic excitation to enhance the coherent vortical structures that form in both a plane jet and a passively modified plane jet. The Strouhal number for the preferred mode based on the nozzle height of the jet is found to be unaffected by the passive modification. The existence of the jet column mode of stable pairing in the excited plane jet is unambiguously confirmed. Measurements in the excited and modified plane jet show that the passive modification suppresses this mode. Finally, the work shows the existence of a new mode of stable pairing. Both time- and phase-averaged measurements are presented to examine this mode.