Global instability analysis of the three-dimensional flow past two roughness elements of different shape, namely a cylinder and a bump, is presented. In both cases, the eigenspectrum is made of modes characterised by a varicose symmetry and localised mostly in the zones of large base flow shear. The primary instability exhibited is the same in both cases and consists in an isolated unstablemode probably related to streaks instability. For the cylinder however, a whole branch of modes is in addition destabilised as the Reynolds number is further increased.
Influence of the shape on the roughness-induced transition / Loiseau, J. -Ch; Cherubini, S.; Robinet, J. -Ch; Leriche, E.. - STAMPA. - 107:(2015), pp. 123-128. [10.1007/978-3-319-06260-0_18]
Influence of the shape on the roughness-induced transition
Cherubini, S.;
2015-01-01
Abstract
Global instability analysis of the three-dimensional flow past two roughness elements of different shape, namely a cylinder and a bump, is presented. In both cases, the eigenspectrum is made of modes characterised by a varicose symmetry and localised mostly in the zones of large base flow shear. The primary instability exhibited is the same in both cases and consists in an isolated unstablemode probably related to streaks instability. For the cylinder however, a whole branch of modes is in addition destabilised as the Reynolds number is further increased.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
