Turbulence enhancement in coaxial jet flows by means of vortex shedding

Authors: Örlü, R., Segalini, A. S., Alfredsson, P.H., Talamelli, A.
Document Type: Book
Pubstate: Published
Journal: Progress in Turbulence III, Springer Proceedings in Physics, Proceedings of the iTi Conference in Turbulence 2008
Volume: 131   235-238
Year: 2009


The present paper confirms experimentally the theoretical result by Talamelli and Gavarini (Flow, Turbul. & Combust., 2006), who proposed that the wake behind the separation wall between the two streams of a coaxial jet creates the condition for an absolute instability. This instability, by means of the induced vortex shedding, provides a continuous forcing mechanism for the control of the flow field. The potential of the found control mechanism is underlined by its ability to enhance the turbulence intensity within the inner and outer shear layer.