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Tiltrotor Aeroacoustic Code (TRAC) Prediction Assessment and Initial Comparisons with Tram Test DataA prediction sensitivity assessment to inputs and blade modeling is presented for the TiltRotor Aeroacoustic Code (TRAC). For this study, the non-CFD prediction system option in TRAC is used. Here, the comprehensive rotorcraft code, CAMRAD.Mod1, coupled with the high-resolution sectional loads code HIRES, predicts unsteady blade loads to be used in the noise prediction code WOPWOP. The sensitivity of the predicted blade motions, blade airloads, wake geometry, and acoustics is examined with respect to rotor rpm, blade twist and chord, and to blade dynamic modeling. To accomplish this assessment, an interim input-deck for the TRAM test model and an input-deck for a reference test model are utilized in both rigid and elastic modes. Both of these test models are regarded as near scale models of the V-22 proprotor (tiltrotor). With basic TRAC sensitivities established, initial TRAC predictions are compared to results of an extensive test of an isolated model proprotor. The test was that of the TiltRotor Aeroacoustic Model (TRAM) conducted in the Duits-Nederlandse Windtunnel (DNW). Predictions are compared to measured noise for the proprotor operating over an extensive range of conditions. The variation of predictions demonstrates the great care that must be taken in defining the blade motion. However, even with this variability, the predictions using the different blade modeling successfully capture (bracket) the levels and trends of the noise for conditions ranging from descent to ascent.
Document ID
20040086961
Acquisition Source
Langley Research Center
Document Type
Conference Paper
Authors
Burley, Casey L.
(NASA Langley Research Center Hampton, VA, United States)
Brooks, Thomas F.
(NASA Langley Research Center Hampton, VA, United States)
Charles, Bruce D.
(Boeing Co. Mesa, AZ, United States)
McCluer, Megan
(NASA Ames Research Center Moffett Field, CA, United States)
Date Acquired
September 7, 2013
Publication Date
January 1, 1999
Subject Category
Aircraft Propulsion And Power
Meeting Information
Meeting: 25th European Rotorcraft Forum
Location: Rome
Country: Italy
Start Date: September 14, 1999
End Date: September 16, 1999
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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