Invariant solutions in a channel flow using a minimal restricted nonlinear model - 04/02/17
Abstract |
Simulations using a Restricted Nonlinear (RNL) system, where mean flow distortion resulting from Reynolds stress feedback regenerates rolls, is applied in a channel flow under subcritical conditions. This quasi-linear restriction of the dynamics is used to study invariant solutions located in the bulk of the flow found recently by Rawat et al. (2016) [[14]]. It is shown that the RNL system truncated to a single streamwise mode for the perturbation supports invariant solutions that are found to bifurcate from a relative periodic orbit into a travelling wave solution when the spanwise size is increasing. In particular, the travelling wave solution exhibits a spanwise localized structure that remains unchanged for large values of the spanwise extent as the invariant solution lying on the lower branch found by Rawat et al. (2016) [[14]]. In addition, travelling wave solutions provided by this minimal RNL system are self-similar with respect to the Reynolds number based on the centreline velocity, and the half-channel height varying from 2000 to 5000.
Le texte complet de cet article est disponible en PDF.Keywords : Channel flow, Invariant solutions, Subcritical transition
Plan
Vol 345 - N° 2
P. 117-124 - février 2017 Retour au numéroBienvenue sur EM-consulte, la référence des professionnels de santé.