par Gopalakrishnan, Shyam Sunder 
;Mandal, Alakesh Chandra
Référence Physics of fluids, 33, 11, 114101
Publication Publié, 2021-11
;Mandal, Alakesh ChandraRéférence Physics of fluids, 33, 11, 114101
Publication Publié, 2021-11
Article révisé par les pairs
| Résumé : | One of the simplest problems involving external vorticity in boundary layer flows is the flow over a semi-infinite plate under a stream of uniform shear. We study the transient growth phenomenon in this flow to investigate the role of freestream shear on energy amplification and analyze the differences with the Blasius flow. The initial optimal disturbance that triggers the maximum growth is found to be streamwise vortices, as in other shear flows. Compared to the Blasius boundary layer, higher optimum energy and larger spanwise wavelength of streamwise vortices have been observed. We provide scaling laws for the maximum optimal amplification, which is found to increase exponentially with the freestream shear gradient. |
