Investigation and prediction of transitional airfoil self-noise
Sandberg, Richard D., Jones, Lloyd E. and Sandham, Neil D. (2009) Investigation and prediction of transitional airfoil self-noise. In, 15th AIAA/CEAS Aeroacoustics Conference (30th AIAA Aeroacoustics Conference), Miami, US, 11 - 13 May 2009. 13pp.
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Description/Abstract
Direct numerical simulations (DNS) have been conducted of the flow over NACA-0006
and NACA-0012 airfoils. The airfoil flows have been found to exhibit pronounced tran-
sitional phenomena and multiple sources of noise have been observed. Data transformed
to the frequency domain, and third-octave averaged, reveal that for low frequencies, the
contribution of trailing edge noise radiation is significant while for the high frequencies the
radiated noise appears to be due only to the flow events in the transition/reattachment
region on the suction side. Cross-correlations of acoustic and hydrodynamic quantities,
combined with ray-acoustic theory, are shown to identify the main source locations. Even
though the cross-correlation maps capture the trailing edge contribution, the highest cor-
relation with the farfield observer locations is found in the transition/reattachment region,
implying that this is the main source region for the transitional cases investigated here.
Surface pressure peaks associated with the transitional behavior lead to decreased accuracy
when predicting self-noise using classical trailing edge theory based on surface pressure dif-
ference. Using data from the DNS the application of ramping functions to Amiet's surface
pressure jump function are evaluated. It is shown that the right choice of ramping function
can considerably improve predictions of the scattered pressure field and the total surface
pressure difference.
| Item Type: | Conference or Workshop Item (Paper) |
|---|---|
| Additional Information: | AIAA 2009-3104 |
| Related URLs: | |
| Subjects: | Q Science > QC Physics T Technology > TL Motor vehicles. Aeronautics. Astronautics |
| Divisions: | University Structure - Pre August 2011 > School of Engineering Sciences > Aerodynamics & Flight Mechanics |
| Item ID: | 185799 |
| Date Deposited: | 11 May 2011 08:29 |
| Last Modified: | 02 Mar 2012 11:55 |
| Contributors: | Sandberg, Richard D. (Author) Jones, Lloyd E. (Author) Sandham, Neil D. (Author) |
| Date: | 2009 |
| Additional Information: | AIAA 2009-3104 |
| Status: | Unpublished |
| URI: | http://eprints.soton.ac.uk/id/eprint/185799 |
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