DMCA
HART-II acoustic predictions using a coupled CFD/CSD method (2009)
| Venue: | in American Helicopter Society 65th Annual Forum |
| Citations: | 2 - 0 self |
BibTeX
@INPROCEEDINGS{Boyd09hart-iiacoustic,
author = {D. Douglas Boyd},
title = {HART-II acoustic predictions using a coupled CFD/CSD method},
booktitle = {in American Helicopter Society 65th Annual Forum},
year = {2009}
}
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Abstract
This paper documents results to date from the Rotorcraft Acoustic Characterization and Mitigation activity under the NASA Subsonic Rotary Wing Project. The primary goal of this activity is to develop a NASA rotorcraft impulsive noise prediction capability which uses first principles fluid dynamics and structural dynamics. During this effort, elastic blade motion and co-processing capabilities have been included in a recent version of the computational fluid dynamics code (CFD). The CFD code is loosely coupled to computational structural dynamics (CSD) code using new interface codes. The CFD/CSD coupled solution is then used to compute impulsive noise on a plane under the rotor using the Ffowcs Williams-Hawkings solver. This code system is then applied to a range of cases from the Higher Harmonic Aeroacoustic Rotor Test II (HART-II) experiment. For all cases presented, the full experimental configuration (i.e., rotor and wind tunnel sting mount) are used in the coupled CFD/CSD solutions. Results show good correlation between measured and predicted loading and loading time derivative at the only measured radial station. A contributing factor for a typically seen loading mean-value offset between measured data and predictions data is examined. Impulsive noise predictions on the measured microphone plane under the rotor compare favorably with measured mid-frequency noise for all cases. Flow visualization of the BL and MN cases shows that vortex structures generated in the prediction method are consist with measurements. Future application of the prediction method is discussed.
Keyphrases
hart-ii acoustic prediction coupled cfd csd method prediction method mitigation activity loading time computational structural dynamic future application rotorcraft acoustic characterization first principle full experimental configuration ffowcs williams-hawkings solver cfd csd flow visualization wind tunnel impulsive noise cfd code elastic blade motion mid-frequency noise new interface code good correlation recent version contributing factor mn case prediction data vortex structure paper document result co-processing capability rotor compare structural dynamic nasa subsonic rotary wing project primary goal code system computational fluid dynamic code mean-value offset radial station coupled cfd csd solution impulsive noise prediction microphone plane
