Diffusion of jets with annular counterflow and small diameter ratio

Dariusz Asendrych (1) , Michel Favre-Marinet (2)

1 Częstochowa University of Technology
2 LEGI - Laboratoire des Écoulements Géophysiques et Industriels [Grenoble]

A new technique was proposed by Strykowski and Wilcoxon (SW) several years ago for improving mixing in axisymmetric jets. In their facility, a countercurrent flow was produced near the jet exit, giving rise to enhancement of the initial jet instabilities. The annular counterflow was created by applying suction to an annular collar placed around the jet nozzle. The authors studied jets exhausting from a nozzle with a large area contraction ratio and a large collar/jet diameter ratio (2). They have shown that the initial jet turbulent activity and diffusion are significantly increased by a strong counterflow. Such a dramatic increase of mixing was also observed in a tube jet with a small gap between the collar and the inner nozzle. These results have confirmed the interest of using counterflow for the control of jet mixing. The technique also seems very promising for applications to combustion. Recently, Asendrych and Drobniak investigated the thermal field of nonisothermal countercurrent jets.

Domaines: Mécanique des fluides [physics.class-ph]; Mécanique des fluides [physics.class-ph]

Dariusz Asendrych, Michel Favre-Marinet. Diffusion of jets with annular counterflow and small diameter ratio. AIAA Journal, 2004, 42 (11), pp.2385-2387. ⟨10.2514/1.2616⟩. ⟨hal-00204635⟩