Acoustic Testing of the Joby Aviation Propeller in the National Full-Scale Aerodynamics Complex 40- by 80-Foot Wind Tunnel
Natasha Schatzman, Lauren Weist, Jeremy Bain, Austin Thai
Abstract
The advanced air mobility sector has progressed in recent years with electric vertical take-off and landing vehicles at the forefront. In response, the NASA Advanced Air Mobility (AAM) project has initiated the AAM National Campaign to partner with industry to progress this emerging market. This resulted in NASA's Revolutionary Vertical Lift Technology project electing to participate in experimental efforts to develop datasets for computational tool validation for these AAM vehicle configurations. AAM vehicles can gain wide adoption if there is sufficient community acceptance; and for community acceptance noise has been identified as a critical obstacle to achieve success in this emerging market. To further understand electric vertical take-off and landing vehicle noise, an isolated Joby Aviation S4 propeller was tested in the National Full-Scale Aerodynamics Complex 40- by 80-Foot Wind Tunnel at NASA Ames Research Center to aid in providing high quality performance, loads, and acoustic data. Details of test hardware and setup are described with a focus on acoustics, which includes facility, test model, microphone locations, and data acquisition system details. Additionally, the data processing techniques and completed test matrix for acoustic points are provided. To aid in identifying potential acoustic reflections, an acoustic reflection test was performed prior to the start of the test and highlighted the presence of reflections at every microphone location. Acoustic results are provided for various flight regimes for sweeps of blade pitch, RPM, flow angle, and wind speed. These results show an optimum RPM for a specific thrust level for noise, and further reductions in RPM can increase noise levels. This dataset will be used to evaluate and improve computational tools within the NASA RVLT Conceptual Design Toolchain.