The Effects of Pylon Installation on the Flow Exhausting a Bypass Turbofan Engine Model.

Authors: Mihaescu, M, Heeb, N., Gutmark, E., Wojno, J.
Document Type: Article
Pubstate: Published
Journal: 3rd Int. Conf. on Jets, Wakes and Separated Flows, Sept 27-30, 2010, Cincinnati, Ohio, USA
Volume:    9 pages
Year: 2010


Jet engine installation effects can significantly affect the behavior of the exhausting flow otherwise axisymmetric for an axial-symmetric nozzle configuration. A joint University of Cincinnati / General Electric (GE) Aviation numerical and experimental study is carried out for analyzing the flow associated with a separate flow nozzle system with and without pylon installation effects. The present paper presents the numerical results associated with this study. The pylon’s presence induces an asymmetry in the flow field, the coaxial jet spreading more in the radial direction underneath the pylon-nozzle assembly. Due to the “Coanda effect” the core stream jet attaches to the pylon and follows its shape until the separation occurs. Moreover, it is pushed in the direction towards the pylon by the longitudinal vortical structures generated due to the fan stream-pylon interaction. Larger turbulent kinetic energy levels are found in the pylon plane, above the jet center-line, in the region located downstream of the pylon where there is a higher interaction between the core and the fan streams. Particle Imaging Velocimetry experimental flow data are used to validate the computational results. The comparison shows an overall fair agreement between the numerical data and the experimental measurements.