Optimal transient growth in compressible turbulent boundary layers
Article dans une revue avec comité de lecture
Date
2015Journal
Journal of Fluid MechanicsRésumé
The structure of zero-pressure-gradient compressible turbulent boundary layers is analysed using the tools of optimal transient growth theory. The approach relies on the extension to compressible flows of the theoretical framework originally developed by Reynolds & Hussain (J. Fluid Mech., vol. 52, 1972, pp. 263–288) for incompressible flows. The model is based on a density-weighted triple decomposition of the instantaneous field into the contributions of the mean flow, the organized (coherent) motions and the disorganized background turbulent fluctuations. The mean field and the eddy viscosity characterizing the incoherent fluctuations are here obtained from a direct numerical simulation database. Most temporally amplified modes (optimal modes) are found to be consistent with scaling laws of turbulent boundary layers for both inner and outer layers, as well as in the logarithmic region, where they exhibit a self-similar spreading. Four free-stream Mach numbers are considered: $\mathit{Ma}_{\infty }=0.2$, 2, 3 and 4. Weak effects of compressibility on the characteristics length and the orientation angles are observed for both the inner- and the outer-layer modes. Furthermore, taking into account the effects of mean density variations, a universal behaviour is suggested for the optimal modes that populate the log layer, regardless of the Mach number. The relevance of the optimal modes in describing the near-wall layer dynamics and the eddies that populate the outer region is discussed.
Fichier(s) constituant cette publication
Cette publication figure dans le(s) laboratoire(s) suivant(s)
Documents liés
Visualiser des documents liés par titre, auteur, créateur et sujet.
-
Article dans une revue avec comité de lecturePIROZZOLI, Sergio; BERNARDINI, Matteo; MARIÉ, Simon; GRASSO, Francesco (Cambridge University Press (CUP), 2015)Direct numerical simulation of the spatially developing mixing layer issuing from two turbulent streams past a splitter plate is carried out under mild compressibility conditions. The study mainly focuses on the early ...
-
Communication avec acteVIENNE, Lucien; MARIE, Simon; GRASSO, Francesco (American Institute of Aeronautics and Astronautics, 2019)The viscous fingering instability is successfully simulated within a lattice Boltzmann framework. Each species of the mixture is governed by its own kinetic equation and a force takes into account the diffusion between ...
-
Article dans une revue avec comité de lectureVIENNE, Lucien; MARIÉ, Simon; GRASSO, Francesco (American Physical Society (APS), 2019)A lattice Boltzmann method for miscible gases is presented. In this model, the standard lattice Boltzmann method is employed for each species composing the mixture. Diffusion interaction among species is taken into account ...
-
Article dans une revue avec comité de lectureBEN HASSAN SAIDI, Ismaïl; SCHMELZER, Martin; CINNELLA, Paola; GRASSO, Francesco (Elsevier Inc., 2022-02)Reynolds-stress models (EARSM) from high-fidelity data is developed building on the frozen-training SpaRTA algorithm of [1]. Corrections for the Reynolds stress tensor and the production of transported turbulent quantities ...
-
Article dans une revue avec comité de lectureThe influence of dense gas effects on compressible turbulence is investigated by means of numerical simulations of the decay of compressible homogeneous isotropic turbulence (CHIT) and of supersonic turbulent flows through ...