Experimental study on the use of the wake instability as a passive control in coaxial jet flows

Authors: Segalini, A. S., Örlü, R., Alfredsson, P.H., Talamelli, A.
Document Type: Book
Pubstate: Published
Journal: Seventh IUTAM Symposium on Laminar-Turbulent Transition, IUTAM Bookseries
Volume: 18   361-366
Year: 2010


The present paper verifies 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 absolute 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 as well as its robustness has been verified and its ability to enhance the turbulence intensity within the inner and outer shear layer has been demonstrated.