Flow Control

Participants: F. Lusseyran, L. Mathelin, L. Pastur, S. Pellerin and B. Podvin.

Fluid flow manipulation and control has become a crucial tool for enhancing aircraft maneuver capabilities, reducing fuel consumption, mitigating aeroacoustic noise or preventing buffeting, to name just a few examples. Beyond aeronautics, flow control is also of interest for ground commercial vehicles to reduce the drag, hence the fuel consumption, at cruise speed. This is further motivated by ever more stringent CO2 emission restrictions whose major reduction is achieved by a decrease in the fuel consumption. Other environmentally motivated examples include the reduction of the noise emitted by open cavities in high speed flows, as encountered between two cars of a high-speed train or in the landing gear system of commercial aircraft.

The team has developed an expertise in all aspects of flow control, covering plasma actuators, wind tunnel experiments, sophisticated visualization techniques (time- and space-resolved PIV, Laser Doppler Anemometry), numerical simulations and methodological developments. Different control strategies have also been considered, ranging from a time-delayed control to stabilize unstable periodic orbits, experimental open loop control of the shear layer of an open cavity flow, reduction of the skin friction of a simulated turbulent flow over a flat plate using a neural network, reduction of the recirculation bubble at the back of a Ahmed body in LES simulations, etc.

Current efforts are devoted to developing closed-loop control strategies as realistic and production-compliant as possible. No linearity is required, neither in the governing equations of the system at hand, nor in the control strategy. The state of the system is efficiently estimated from a few wall-mounted sensors using sophisticated mathematical tools and a reinforcement learning-based approach is also developed for deriving the closed-loop control policy. Other current efforts involve the reduction of the drag of an Ahmed body with three-dimensional turbulent flow simulations and the reduction of the pressure fluctuations (related to the radiated noise) at the downstream edge of an open cavity flow.

Main collaborations:

Collaborations include Florida State University (M.Y. Hussaini), Institut PPrime (B. Noack, L. Cordier, P. Jordan), Ecole Normale Superieure de Cachan - SATIE (H. Abou-Kandil, M. Abbas-Turki), ONERA (D. Sipp), LadHyX (L. Lesshafft), ENSTA (O. Cadot), Sup'Elec - L2S (Y. Chitour, L. Greco, S. Tliba).
Direct link: FlowCon