Quadcopter Noise Prediction with the Lattice Boltzmann Method

Speaker: Francois Cadieux, NASA Advanced Supercomputing Division, NASA Ames Research Center
November 18, 2019

Presentation

Abstract

From small delivery Unmanned Aircraft Systems (UAS) to short-haul building-to-building air taxis, vertical take-off and landing aircraft are gaining traction as a new approach to tackle the problem of transportation of goods and people in densely populated areas. Beyond safety, one of the chief concerns of communities where drones are becoming more popular is the noise they generate. The ability to predict the acoustics of new conceptual aircraft with multiple rotors and complex fuselages is critical to enable the creation of quieter designs. Using the Launch, Ascent, and Vehicle Aerodynamics (LAVA) software’s Cartesian adaptive mesh refinement (AMR) capability, we established best practices and assessed the accuracy and cost of small quadcopter noise predictions with the Lattice-Boltzmann method (LBM) coupled with a far-field acoustics solver. Results from our finest scale-resolving LBM simulations are in good agreement with wind tunnel measurements [1] across a wider range of frequencies than has ever been demonstrated.

[1]: Zawodny, N., and Pettingill, N., “Acoustic wind tunnel measurements of a quadcopter in hover and forward flight conditions,” INTER-NOISE and NOISE-CON Congress and Conference Proceedings , Vol. 258, Institute of Noise Control Engineering, 2018, pp. 487–500.

Biography

Francois Cadieux is a research scientist for Science and Technology Corporation working in the Computational Aerosciences Branch of the NASA Advanced Supercomputing Division at NASA's Ames Research Center. He received the NASA Early Career Public Achievement Medal in 2018 for enhancing the safety and success of the Orion Launch Abort System through high-fidelity computational aero-acoustic predictions of the QM-1 test and launch abort scenarios. Cadieux joined the launch ascent and vehicle aerodynamics (LAVA) group in September 2016. He completed a postdoctoral fellowship at the Flow Physics and Computation Lab under the supervision of Prof. Rajat Mittal at Johns Hopkins University from 2015 to 2016. His research focused on developing and validating wall-modeled large-eddy simulation (LES) for separated flows. Cadieux also investigated the dynamics of active flow control to mitigate flow separation and delay stall. During his graduate work with Prof. Julian A. Domaradzki, Cadieux probed the limits of under-resolved LES for separated flows applicable to small unmanned aerial vehicles and low-pressure turbines and quantified the importance of numerical dissipation effects when performing LES on such coarse grids. He obtained his Ph.D. in aerospace engineering from the University of Southern California in 2015.