Vortices and large - scale structures in a rough open - channel flow subjected to bed suction and injection / Arindam Singha in Journal of engineering mechanics, Vol. 138 N° 5 (Mai 2012)  

Vortices and large - scale structures in a rough open - channel flow subjected to bed suction and injection [texte imprimé] / Arindam Singha, Auteur ; Md. Abdullah Al Faruque, Auteur ; Ram Balachandar, Auteur . - 2012 . - pp.491-501.
Mécanique appliquée
Langues : Anglais (eng)
in Journal of engineering mechanics > Vol. 138 N° 5 (Mai 2012) . - pp.491-501

Mots-clés :	Seepage Open channel flow Vortices Large-scale-structures Swirling strength Proper orthogonal decomposition
Résumé :	The effect of seepage (injection and suction) on the dynamics of vortices and large-scale structures in a rough open channel flow was examined experimentally. The velocity measurements in the open channel flow were carried out using particle image velocimetry. A swirling strength-based vortex identification algorithm was used to extract the location, size, and strength of vortices in the flow. Proper orthogonal decomposition (POD) was used to analyze the dynamics of large-scale structures in the flow. The results indicate that suction induces a greater change compared with an equivalent amount of injection on the open channel flow. Suction dampens the size and strength of the vortices compared to the no-seepage case. POD analysis indicates that seepage tends to introduce more small-scale structures in the flow and destroys the large-scale organized motion present otherwise in the flow.
ISSN :	0733-9399
En ligne :	http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29EM.1943-7889.0000354