[Direct-numerical simulation of the splitting-plate downstream-shape influence upon a mixing layer]
In this Note, we present direct numerical simulation results of a spatial mixing layer generated behind an upstream plate separating two boundary layers. The effect of the shape of the trailing edge of the plate is considered through comparisons between flows obtained from a bevelled or a blunt plate. In the former case, a spatial mixing layer consistent with previous experimental and numerical observations is obtained. In the latter case, the self-excited state that establishes in the near wake region dominates primary and secondary instability mechanisms while understating the importance of inflow perturbations. This behaviour is interpreted in terms of convective or absolute instability. The effects on turbulent statistics are also discussed.
Dans cette Note, nous présentons des résultats de simulation numérique directe d'une couche de mélange spatiale obtenue par mise en contact de deux couches limites se développant de chaque côté d'une plaque séparatrice placée en amont. L'effet de la forme du bord de fuite de la plaque est considéré par comparaison des écoulements obtenus à partir d'une plaque à bord mince ou épais. Dans le premier cas, une couche de mélange spatiale conforme à de précédentes observations expérimentales et numériques est obtenue. Dans le second cas, l'état d'auto-excitation qui s'installe dans la zone de sillage domine l'ensemble des mécanismes d'instabilités primaires et secondaires en minorant l'importance des perturbations amont. Ces comportements sont interprétés en termes d'instabilité convective ou absolue. Les effets sur les statistiques turbulentes principales sont également discutés.
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Keywords: Computational fluid mechanics, Instability, Turbulence, Mixing layer
Sylvain Laizet 1; Eric Lamballais 1
@article{CRMECA_2006__334_7_454_0,
author = {Sylvain Laizet and Eric Lamballais},
title = {Simulation num\'erique directe de l'influence de la forme aval d'une plaque s\'eparatrice sur une couche de m\'elange},
journal = {Comptes Rendus. M\'ecanique},
pages = {454--460},
publisher = {Elsevier},
volume = {334},
number = {7},
year = {2006},
doi = {10.1016/j.crme.2006.06.005},
language = {fr},
}
TY - JOUR AU - Sylvain Laizet AU - Eric Lamballais TI - Simulation numérique directe de l'influence de la forme aval d'une plaque séparatrice sur une couche de mélange JO - Comptes Rendus. Mécanique PY - 2006 SP - 454 EP - 460 VL - 334 IS - 7 PB - Elsevier DO - 10.1016/j.crme.2006.06.005 LA - fr ID - CRMECA_2006__334_7_454_0 ER -
%0 Journal Article %A Sylvain Laizet %A Eric Lamballais %T Simulation numérique directe de l'influence de la forme aval d'une plaque séparatrice sur une couche de mélange %J Comptes Rendus. Mécanique %D 2006 %P 454-460 %V 334 %N 7 %I Elsevier %R 10.1016/j.crme.2006.06.005 %G fr %F CRMECA_2006__334_7_454_0
Sylvain Laizet; Eric Lamballais. Simulation numérique directe de l'influence de la forme aval d'une plaque séparatrice sur une couche de mélange. Comptes Rendus. Mécanique, Volume 334 (2006) no. 7, pp. 454-460. doi : 10.1016/j.crme.2006.06.005. https://comptes-rendus.academie-sciences.fr/mecanique/articles/10.1016/j.crme.2006.06.005/
[1] Large- and small-scale stirring of vorticity and a passive scalar in a 3-D temporal mixing layer, Phys. Fluids A, Volume 4 (1992) no. 12, pp. 2761-2778
[2] Streamwise vortices in large-eddy simulations of mixing layers, Eur. J. Mech. B/Fluids, Volume 17 (1998) no. 4, pp. 615-637
[3] Large-Eddy Simulation of Turbulence, Cambridge Univ. Press, 2005
[4] S. Laizet, E. Lamballais, Compact schemes for the DNS of incompressible flows: in what context is the quasi-spectral accuracy really useful? in: Proc. IV Escola de Primavera de Transiçao e Turbulência, Porto Alegre, RS, Brazil, 2004
[5] P. Parnaudeau, E. Lamballais, D. Heitz, J.H. Silvestrini, Combination of the immersed boundary method with compact schemes for DNS of flows in complex geometry, in: Proc. DLES-5, Munich, 2003
[6] L. Perret, J. Delville, J.-P. Bonnet, Investigation of the large scale structures in the turbulent mixing layer downstream a thick plate, in: Proc. 3rd International Symposium on Turbulence and Shear Flow Phenomena, Sendai, Japan, 2003
[7] L. Perret, Etude du couplage instationnaire calculs-expériences en écoulements turbulents, PhD thesis, Université de Poitiers, 2004
[8] Low-dimensional analysis, using POD, for two mixing layer-wake interactions, Int. J. Heat Fluid Flow, Volume 25 (2004) no. 3, pp. 351-363
[9] Streamwise vortex structure in plane mixing layer, J. Fluid Mech., Volume 170 (1989), pp. 499-525
[10] A note on spanwise structure in the two-dimensional mixing layer, J. Fluid Mech., Volume 93 (1980), pp. 325-336
[11] Local and global instabilities in spatially developing flows, Annu. Rev. Fluid Mech., Volume 22 (1990), pp. 473-537
[12] Linear instability characteristics of wall-shear layers, Phys. Fluids, Volume 4 (1992) no. 1, pp. 189-191
[13] Global instabilities in spatially developing flows: non-normality and nonlinearity, Annu. Rev. Fluid Mech., Volume 37 (2005), pp. 357-392
[14] J.-P. Bonnet, R.D. Moser, W. Rodi, Free shear flows, in: Report of the fluid dynamics panel working group 21, editor, A selection of test cases for the validation of large-eddy simulations of turbulent flows, vol. 245, AGARD, 1998, pp. 29–35
[15] Generation of inflow data for spatially-developing boundary layer simulations, J. Comp. Phys., Volume 140 (1998), p. 233
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