Clément Nardari

This paper presents the computational results of SIMULIA PowerFLOW ® compared to the experimental investigation provided at the 1st AIAA Workshop for Integrated Propeller Prediction (WIPP). Due to the renewed and growing interest in eVTOL aircraft and limited publicly available experiments, this workshop provided integrated propeller data for assessment of computational tools. The objective of the workshop was to provide open-access wind tunnel data to evaluate wingtip-mounted propellers… Show more

This paper presents the computational results of SIMULIA PowerFLOW ® compared to the experimental investigation provided at the 1st AIAA Workshop for Integrated Propeller Prediction (WIPP). Due to the renewed and growing interest in eVTOL aircraft and limited publicly available experiments, this workshop provided integrated propeller data for assessment of computational tools. The objective of the workshop was to provide open-access wind tunnel data to evaluate wingtip-mounted propellers. Understanding this complex aerodynamic interaction is essential to improve wingtip-mounted propeller design. In order to reduce design time and development cost for this type of vehicle configuration, accurate computational tools are required. These tools will need to capture the complex unsteady flow interactions to optimize the wing-propeller aerodynamic integrated design. However, the accuracy of these tools must first be established. Therefore, PowerFLOW simulations are performed and compared to experimental measurements of wing surface pressure, lift, drag and thrust coefficients. Predication accuracy for wing-propeller interaction is demonstrated by comparing different propeller RPM and wing angle of attack with and without the wingtip-mounted propeller. In addition, experimental measures are limited due to the intrusiveness of the measurement which can lead to a lack of understanding in the physics of the flow and impact the overall wing-tip-mounted propeller performance. Therefore, PowerFLOW unsteady simulations yield insight of propeller-wing wake interactions to better understand the aerodynamic efficiency benefits of a wingtip-mounted propeller. Show less

The primary objective of the present study is to investigate the impact of the recirculating
flow that develops inside a closed, hemi-anechoic test chamber on the noise generation mechanisms
of a drone rotor operated under static thrust conditions. To that end, Lattice-Boltzmann
simulations are conducted for both an idealized, semi-infinite free-field and a confined, hemianechoic
domain that models the test chamber, with the latter validated against experimental
measurements… Show more

The primary objective of the present study is to investigate the impact of the recirculating
flow that develops inside a closed, hemi-anechoic test chamber on the noise generation mechanisms
of a drone rotor operated under static thrust conditions. To that end, Lattice-Boltzmann
simulations are conducted for both an idealized, semi-infinite free-field and a confined, hemianechoic
domain that models the test chamber, with the latter validated against experimental
measurements. Comparison between simulations reveals a significant increase in rotor noise
due to confinement, up to 5 dBA in overall sound pressure level depending on microphone
location, with negligible impact on aerodynamic performance. Blade-strip and beam-forming
source identification techniques are utilized to determine those sound-generation mechanisms
responsible for the increase in rotor noise. Leading-edge interactions between the vortical
structures convected by the recirculating flow and the rotor’s blades are demonstrated to be
directly responsible for the generation of unsteady loads that lead to significantly higher blade
passing frequency harmonic peaks. A small enhancement of the high-frequency self-noise
contribution is also observed, whereas blade-tip vortex dynamics are largely unaffected by
confinement so that the contribution of blade-vortex interaction noise is negligible. Show less

Nardari, C., Mann, A., and Schindele, T., "Exhaust and Muffler Aeroacoustics Predictions using Lattice Boltzmann Method," SAE Technical Paper 2018-01-1287, 2018, https://doi.org/10.4271/2018-01-1287.