On the Kutta Condition for Sound Transmission in an Annular Cascade of Vanes

Benjamin François (1) , Simon Bouley (1) , Michel Roger (1)

1 LMFA - Laboratoire de Mecanique des Fluides et d'Acoustique

The present work deals with the analytical formulation of sound transmission through the outlet guide vanes of a subsonic axial-flow fan. Drastic approximations on the geometry and the flow features are necessary in order to produce tractable, closed-form solutions. Because the exit flow from outlet guide vanes must be axial, the vanes are nearly parallel to the axis at the trailing-edge. They can be modeled as an annular cascade of axially aligned and zero-thickness plates. This simplification remains representative of a system of non-parallel vanes with hub and carter rigid-wall boundary conditions. The flow is considered as homoentropic and inviscid of uniform axial Mach number M. Previous studies by Howe and Rienstra highlighted the importance of the Kutta condition in the formulation of such sound transmission problems. Recently, Bouley showed that, in a 2D reduction of the same problem, the scattered acoustic fields can be significantly overestimated when this condition is not imposed.

Domaines: Mécanique [physics]

Benjamin François, Simon Bouley, Michel Roger. On the Kutta Condition for Sound Transmission in an Annular Cascade of Vanes. 16th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery, Apr 2016, Honolulu, United States. ⟨hal-01891313⟩