Aeroacoustic predictions of the free-wake model, vortex particle method, and computational fluid dynamics for a coaxial rotor system

Kalki Sharma, Kenneth S. Brentner, Zhongqi Jia, Seongkyu Lee, Phuriwat Anusonti-Inthra

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Scopus citations

Abstract

In this paper the aeroacoustic results using the Free-Wake Model (FWM), Vortex Particle Method (VPM), and Computational Fluid Dynamics (CFD) are compared with one another. The FWM and VPM is performed using the software Rotorcraft Comprehensive Analysis System (RCAS), and CFD analysis is performed using the software Helios. Analysis is performed on a lift-offset coaxial rotor system operating at 150 knots in forward flight and 0° shaft tilt. First, the blade loads are compared and then the acoustics using the noise prediction software PSU-WOPWOP. The major difference between the analysis methods is the manner in which they capture aerodynamic interactions. And the differences in the interactions result in differences in the acoustic results. The primary interactions are the blade vortex interactions (BVI), and the blade crossover interactions (BCI). The BVI events occur when a rotor operates in the wake of its own rotor or another rotor, and the BCI events occur when the blades of the upper and lower rotors cross one another. The BVI events are captured by all three methods, but there are variations in location and intensity between the three methods. On the other hand, the VPM and CFD capture the BCI events, but the VPM is unable to capture the BCI events on the retreating side of the upper rotor. These differences in the prediction of the interactions results in variations in directivity as well as intensity of the noise results. Upon analysis of the aeroacoustic results it is concluded that the inability of the FWM and VPM to capture some of the primary interactions capture by CFD can lead to major discrepancies between the acoustic results of the three methods.

Original languageEnglish (US)
Title of host publicationAeromechanics for Advanced Vertical Flight Technical Meeting 2020, Held at Transformative Vertical Flight 2020
PublisherVertical Flight Society
Pages48-65
Number of pages18
ISBN (Electronic)9781713806332
StatePublished - 2020
EventAeromechanics for Advanced Vertical Flight Technical Meeting 2020, Held at Transformative Vertical Flight 2020 - San Jose, United States
Duration: Jan 21 2020Jan 23 2020

Publication series

NameAeromechanics for Advanced Vertical Flight Technical Meeting 2020, Held at Transformative Vertical Flight 2020

Conference

ConferenceAeromechanics for Advanced Vertical Flight Technical Meeting 2020, Held at Transformative Vertical Flight 2020
CountryUnited States
CitySan Jose
Period1/21/201/23/20

All Science Journal Classification (ASJC) codes

  • Aerospace Engineering
  • Control and Systems Engineering
  • Electrical and Electronic Engineering

Fingerprint Dive into the research topics of 'Aeroacoustic predictions of the free-wake model, vortex particle method, and computational fluid dynamics for a coaxial rotor system'. Together they form a unique fingerprint.

Cite this