Online Seminar on Experimental feedback control of separated and open-cavity flows with MEMS Technologies by Dr Thomas Arnoult

Abstract

Flow control is a multidisciplinary domain combining fluid dynamics, control theory and technology design, which aims at modifying a flow natural behaviour in order to obtain positive changes. Fluid dynamics helps understanding the physics of plants to be controlled and set the objectives to be reached, such as lift enhancement, drag or noise reduction or limiting induced structural vibrations. Control theory helps defining the most adapted control strategy to be employed in the case of reactive control. Technology design, based on fluid dynamics and control theory requirements, helps conceiving adapted actuating and sensing technologies. In this work closed-loop control of two canonical flow configurations is proposed: one targeting the control of a separated flow over a NACA 4412 plain flap and one focusing on the control of flow instabilities developing in an open-cavity flow. On the plain flap configuration, the control is implemented with conventional technologies but the focus is brought onto the implementation of two novel control laws, which successfully counter the development of the separated flow. Further measurements show the control robustness towards variations in the flow conditions. However, on such a configuration, one aims at modifying the flow mean properties without benefiting from the flow natural instabilities. The second case focuses on an open-cavity flow, on which control can benefit from the flow natural instabilities. Closed-loop control of this flow configuration is implemented with MEMS (Micro Electro Mechanical Systems) actuators and is based on the design of a controller using a structured H_∞ approach. Closed-loop control experiments damp the open-cavity flow resonance by 13 dB and highlight the controller robustness properties. 

Biography

Thomas Arnoult received the Engineering Degree from ISAE-ENSMA (Institut Supérieur de l’Aéronautique et de l’Espace-Ecole Nationale Supérieure de Mécanique et d’Aérotechnique) and a Degree of Master of Science in Aerospace Dynamics from the Cranfield University (United Kingdom). After graduation in December 2019, he obtained his PhD degree in Mach 2023 at the IEMN, UMR CNRS 8520 Institute, in partnership with the ONERA, the French Aerospace Lab, regarding the use of innovative micro-actuators and micro-sensors in active flow control strategies.

Notice: This event is open to public in respect with the VKI eligibility criteria.