Research

 Flapping & revolving wings

Collaborations : Institut Pprime (Laurent David), Caltech (Tim Colonius), Silmach (Jean-Renaud Frutos)

PhD student : Daniel Diaz

We investigate on the aerodynamics of natural flyers, such as hummingbirds, dragonflies or maple seeds. Of particular interests are (i) the dynamics of the leading edge vortex on revolving wings, (ii) fluid-structure interactions on flapping wings and (iii) the development of bio-inspired nano-flying-robots.

 Highly maneuverable vehicles

Collaborations : ENAC (Murat Bronz), Delair-Tech (Stéphane Terrenoir)

PhD student : Yuchen Leng

Highly maneuverable vehicles undergo drastic changes in flight attitude, which favors highly unsteady aerodynamic phenomena. Added mass effects, massive flow separation and subsequent vortex-vehicle interactions may occur, which in turn affect the aerodynamic loads experienced by the vehicle. Here, we characterize these unsteady phenomena and develop reduced order models to predict the resulting forces (side-figure: credit Delair-Tech).

 Compressible low Reynolds number flows

Collaborations : ONERA (Hervé Bézard)

PhD students : Laura-Victoria Rolandi, Thibault Désert

Recent applications such as flight on Mars and in the stratosphere or high speed trains in low-pressure tubes (hyperloop) require to understand the physics of compressible low-Reynolds number flows. Toward that end, we principally focus on (i) the fundamental analysis of bluff body wakes through linear stability approaches and Direct Numerical Simulations (DNS) and (ii) the development of Unmanned Air Vehicles (UAV) for Mars exploration.

 Rotor aeroacoustics

Post-Doc fellows : Yeongmin Jo

Helicopter blades generate noise through complex aeroacoustic phenomena including blade-vortex interactions and shocks. These sources of noise may be mitigated and/or enhanced as Reynolds and Mach numbers are varied. We attempt to classify sources of noise as Reynolds and Mach numbers are decreased to values typical of flying taxis and drones using Large Eddy Simulations (LES) coupled with Ffowcs Williams and Hawkings approaches. These high-fidelity approaches are validated upon experimental tests conducted in anechoic room and compared with reduced order models (e.g. Blade Element Momentum Theory, Vortex Lattice Methods) which are then used to design aeroacoustically stealth rotors.