Project ACOUDRONE: Towards Silent Micro Air Vehicles

Summary
The demand in Micro-Air Vehicles (MAV) is increasing as well as their potential missions, many of which take place in urban area. Whether for discretion in military operations or noise pollution in civilian use, noise of MAV has to be reduced. So far, beside relatively recent research performed at NASA, and TU-Delft, aeroacoustic research has mainly been focusing on large high-speed rotorcrafts, now
yielding significant improvements and original shape designs. An active field of aeroacoustic research at ISAE-SUPAERO is dedicated to reduce the noise produced by small rotors and their interaction with the fuselage. This is a challenge since MAV’s operate at relatively low Reynolds and Mach numbers. A significant first step has been achieved in 2020-2021 using an in-house optimization tool that combines
a medium fidelity Non-linear Vortex Lattice Method (NLVLM) with a FW-H analogy. Optimized geometries are 3-D printed and tested in an anechoic room. In a companion PhD study, wall-resolved Large Eddy Simulation (LES) were performed. The simulations were based on structured meshes with hundreds of millions of hexahedral elements using our in-house massively parallel compressible Navier Stokes solver IC3. Recently, a characterization of a low Reynolds number two- bladed rotor in interaction with a beam has been performed using both an experimental campaign performed in an anechoic room, LES, and medium fidelity NLVLM methods.

Expected skills
Applicants who are expected to have a PhD in a field related to the subject, should have a background in fluid mechanics, applied mathematics, unsteady CFD methods and/or experimental methods. More precisely, special skills in aeroacoustics, unsteady aerodynamics, and turbulence are expected to allow for a prompt start. Similarly, some knowledge of data processing, as required to post-process data from flow and sound computations as well as from measurements, are also an important asset. Some practical know-how in experimental techniques and a background in rotor aerodynamics would also be welcome. Furthermore, candidates should feel at ease in the UNIX environment.