Session: 05-09-01 Open Source CFD Applications

Paper Number: 65363

Start Time: August 11th, 12:50 PM

65363 - Aeroacoustic Analysis of a UAV Propeller Operable at Various Altitudes 

With the development of Unmanned Aircraft Systems (UASs), demand for Unmanned Air Vehicles (UAVs) is increasing worldwide. UAVs have been developed for a wide range of applications such as delivery, construction, entertainment, agriculture, and military purposes. With the technological development and the wide application range of UAV, the regulation of UAV altitude limits in many countries is further relaxed, and the problem of UAV noise pollution has emerged with the recent advent of the Urban Air Mobility (UAM) and Personal Air Vehicle (PAV) markets. In this study, one typical propeller, the 15X5 propeller of a T-motor, was analyzed by use of commercial computational fluid dynamics (CFD) software, ANSYS FLUENT V19.3. The effects of gravity and convection were analyzed to determine the noise characteristics at altitude using the FW-H equation. A high-altitude drone, which operates at heights from 0 to 10 km with 1,000 to 5,000 revolutions per minute, was analyzed using the steady-state k-w SST turbulence model. And using the steady-state data to initialize values, a transient analysis was calculated with the LES turbulence model. The time step was divided based on the 1-degree rotational time, and the velocity residual on each axis was calculated until a value of 10^-7 or less was achieved and no fluctuation of thrust, at which point it was considered converged. The CFD results were validated with the experimental data for thrust and the maximum error was 8.64%. The Overall Sound Pressure Level (OASPL) was calculated, and noise characteristics in the audible frequency range according to receiver points were also compared. Through this study, thrust and noise data according to altitude were provided. The aerodynamic and aero-acoustic characteristics at high altitudes that are generally difficult to measure by experiment are also presented. Therefore, considering the operational altitude of UAV, the appropriate operating altitude and rotational speed will be presented through the aero-acoustics analysis corresponding to that altitude, and the basic research data can then be applied to the upcoming UAS market.

 

Presenting Author: Ji-Hun Song Sungkyunkwan University

Authors:

Ji-Hun Song Sungkyunkwan University
Seungsoo Jang Sungkyunkwan University
Youn-Jea Kim Sungkyunkwan University