Shear Layer and Shedding Modes Excitations of a Backward-Facing Step Flow by Surface Plasma Discharge
The present experimental study interests in determining the influence of a linear plasma actuator (dielectric barrier discharge) on the development of a separated turbulent shear layer. More specifically, the plasma actuator is used to impose periodic perturbations at the step corner of a backward-facing step. Two different modes of excitation are explored. One concerns the shear layer mode of instability, a mode whose amplification leads to a minimization of the recirculation bubble. The present investigation shows how a dielectric barrier discharge plasma actuator can impose periodic perturbations that excite the shear layer mode and result in a strong regularization of the vortex street. The case of excitation at the shedding mode is also experimentally investigated using a DBD actuator. The measurements show the increase in Reynolds stress caused by this excitation as well as the specific growing mechanism of the shear layer. Indeed, phase-averaged flow measurements highlights the difference in the mechanism of development of the shear layer regarding the type of excitation used, the shear layer mode promoting a growing mechanism by fluid entrainment while the shedding mode enhancing the pairing of successive vortical flow structures.
KeywordsFlow control Plasma actuator Turbulent shear layer Triple decomposition PIV
This work was supported by FP7/2010-2013, MARS (grant agreement no. 266326). A part of the equipment has been funded by the French Government program “Investissements d’Avenir” (LABEX INTERACTIFS, reference ANR-11-LABX-0017-01).
- 6.Bhattacharjee S, Scheelke B, Troutt TR (1986) Modification of vortex interactions in a reattaching separated flow. AIAA J 24Google Scholar
- 8.Yoshioka S, Obi S, Masuda S (2001) Turbulence statistics of periodically perturbed separated shear over a backward-facing step. Int J Heat Fluid Flow 22:393–401Google Scholar
- 10.d’Adamo J, Sosa R, Artana G (2014) Active control of a backward facing step flow with plasma actuators. J Fluid Eng 136Google Scholar
- 12.Sujar-Garrido P, Benard N, Moreau E, Bonnet JP (2015) Dielectric barrier discharge plasma actuator to control turbulent flow downstream of a backward-facing step. Exp Fluids 56:70Google Scholar
- 16.Martin RA, Kaul UK (2014) Optimization of perturbation parameters for simulated free shear layer flow. AIAA 2014-2223Google Scholar
- 17.Cherry NJ, Hillier R, Latour P (1984) Unsteady measurements in a separated and reattaching flow. J Fluid Mech 44Google Scholar
- 18.Driver DM, Seegmiller HL, Marvin JG (1987) Time-dependent behavior of reattaching shear layer. AIAA J 25Google Scholar
- 21.Mansour NN, Hussain F, Buell C (1988) Subharmonic resonance in a mixing layer. In: Proceedings of the summer program, Center for Turbulent ResearchGoogle Scholar
- 22.Paschereit CO, Wygnanski I (1991) Instabilities in the axisymmetric jet: subharmonic resonance. In: Unger Y, Branover H (eds) Advances in turbulence studies. Progress in Astronautics and aeronautics. https://doi.org/10.2514/4.866227
- 25.Sujar-Garrido P (2014) Active control of the turbulent flow downstream of a backward facing step with dielectric barrier discharge plasma actuators. Ph.D. thesis, University of PoitiersGoogle Scholar
- 26.Aono H, Sekimoto S, Sato M, Yakeno A, Nonomura T, Fujii K (2015) Computational and experimental analysis of flow structures induced by a plasma actuator with burst modulations in quiescent air. Mech Eng J 2Google Scholar
- 36.Raman G, Rice EJ (1989) Subharmonic and fundamental high amplitude excitation of an axisymmetric jet. AIAA paper 1989-0993Google Scholar