Sensitivity analysis of optimal transient growth for turbulent boundary layers
Article dans une revue avec comité de lecture
Structural approaches based on modal decomposition of the flow dynamics have gained acceptance for a wide variety of turbulent shear flows. In this context, a singular value decomposition associated with a governing operator, aiming to model the linear amplification of coherent structures, is used to reproduce some fundamental motions in a turbulent boundary layer. In particular, as already found by Cossu et al. (2009), elongated streaky structures scaled in inner and outer units are identified. The sensitivity of these singular values to a mean flow modification is analysed. It is illustrated that the linear amplification of very large-scales which populate the outer motion is not affected when the leading singular value associated with the inner layer is damped. Moreover, we notice that the resulting optimal mean flow deviation is consistent with findings of Xu et al. (2007) in which the active control of a turbulent boundary layer is studied through direct numerical simulations.
Files in this item
Showing items related by title, author, creator and subject.
Article dans une revue avec comité de lectureFADLA, Fawzi; ALIZARD, Frédéric; KEIRSBULCK, Laurent; ROBINET, Jean-Christophe; LAVAL, Jean-Philippe; FOUCAUT, Jean-Marc; CHOVET, Camila; LIPPERT, Marc (Elsevier, 2019)Dynamical behavior of the turbulent channel flow separation induced by a wall-mounted two-dimensional bump is studied, with an emphasis on unsteadiness characteristics of vortical motions evolving in the separated flow. ...
Three-dimensional instability of a ow past a sphere: Mach evolution of the regular and Hopf bifurcations Article dans une revue avec comité de lectureSANSICA, Andrea; ROBINET, Jean-Christophe; ALIZARD, Frédéric; GONCALVES, Eric (Cambridge University Press (CUP), 2018)A fully three-dimensional linear stability analysis is carried out to investigate the unstable bifurcations of a compressible viscous fluid past a sphere. A time-stepper technique is used to compute both equilibrium states ...
Communication avec acteGUIHO, F.; ALIZARD, Frédéric; ROBINET, Jean-Christophe (Springer, 2015)The linear global stability of an interaction between an oblique shock wave and a laminar boundary layer is carried out for various oblique shock angles. It is illustrated that such a flow acts as a noise amplifier. The ...
Article dans une revue avec comité de lectureALIZARD, Frédéric; ROBINET, Jean-Christophe; GLOERFELT, Xavier (Elsevier, 2012)This work is dedicated to the presentation of a matrix-free method for global linear stability analysis in geometries composed of multi-connected rectangular subdomains. An Arnoldi technique using snapshots in subdomains ...
The onset of three-dimensional centrifugal global modes and their nonlinear development in a recirculating flow over a flat surface Article dans une revue avec comité de lectureCHERUBINI, Stefania; ROBINET, Jean-Christophe; DE PALMA, Pietro; ALIZARD, Frédéric (American Institute of Physics, 2010)The three-dimensional stability dynamics of a separation bubble over a flat plate has been studied in both linear and nonlinear conditions. Using a global eigenvalue analysis, two centrifugal global modes are identified: ...