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Yueping Guo

Publications and source records attributed to Yueping Guo.

28 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

Flight Effects of Turbofan Fan Tones

This paper presents a summary and status of the ongoing development of an all-new fan tone noise prediction process. This process is being developed based on data from both the Quiet Technology Demonstrator 2 (QTD2) and the NASA/Boeing Propulsion Aeroacoustics & Aircraft System Noise (PAA/ASN) tests. The fan tone prediction model development steps are outlined, and rationale for a framework is provided. The two most significant findings of this work are how the fan tone noise correlates best with relative tip Mach number and the change in the directivity of the inlet tone noise relative to the aft. Using the framework, an initial proposed model has been developed which reduces the overall fan tone noise prediction miss on a power-level basis from +/- ~25dB to +/- ~5dB. This is expected to greatly improve the ability to predict both current and future aircraft concepts.

Fan Noise↗
NASA NTRSDate not supplied

Turbofan Aft-Radiated Broadband Acoustic Flight Effects

This paper presents the status and on-going development of a new model for the prediction of aft-radiated turbofan broadband noise. The proposed model is developed using data from two full-scale flight tests, the Boeing Quiet Technology Demonstrator 2 (QTD2) and the NASA/Boeing Propulsion Airframe Aeroacoustics and Aircraft System Noise (PAA&ASN) flight tests. The proposed model accounts for an observed coupling between directivity and fan relative tip Mach number. Additional features such as improved spectral and directivity characteristics are discussed. Significant improvements over prior methods implemented in the NASA Aircraft Noise Prediction Program are demonstrated, and predicted deltas to measured levels are reduced from +10/-20 dB to +/-3 dB or better at the most relevant frequencies. This is expected to greatly improve the ability of NASA to predict the noise of both current and future aircraft concepts.

Fan Noise↗
NASA NTRSDate not supplied

Design of an Acoustic Shielding Flap Concept with Prediction and Validation

As part of a NATO task group, NASA has designed a noise reduction technology called a Shielding Flap for application to a hybrid wing body aircraft concept. The design drivers and objectives for this technology are outlined in this paper. Design parameters are defined, and recently-developed NASA software for prediction of acoustic scattering is used to investigate the expected performance of the technology for a range of parameter values. Detailed scattering computational results are presented for several simulated noise sources and for many variations of the shielding flap concept. A selection of computational results is compared with experimental data collected in the NASA Langley Quiet Flow Facility. Overall, the results indicate that the Shielding Flap has strong potential to reduce aft-radiated noise, which was a primary design objective, by shielding sound from the simulated sources while also shielding sound that is scattered from the main airframe.

Propulsion Airframe Aeroacoustics↗
NASA NTRSDate not supplied

Refined Predictions Compared with the Propulsion Airframe Aeroacoustics and Aircraft System Noise Flight Research Test Data

In a collaboration between NASA and The Boeing Company, the Propulsion Airframe Aeroacoustics and Aircraft System Noise Flight Research Test was executed by the Boeing ecoDemonstrator Program in 2020 with an Etihad Airways Boeing 787-10 aircraft. This ambitious flight research successfully accomplished many objectives and constitutes the most comprehensive and highest quality acoustic flight data available to NASA for a modern commercial subsonic transport aircraft. One purpose of these data is to be the measure of accuracy for the aircraft system noise prediction capabilities of NASA. This research reviews the impact of the major improvements in prediction methods implemented up to this point and tested in the Research version of the NASA Aircraft Noise Prediction Program. The improvements have been to the prediction of jet source and jet-flap interaction, to both fan broadband and tone source prediction, and to the prediction of propulsion airframe aeroacoustic scattering effects. In general, over the engine power range, comparisons between prediction and flight data are within 2 EPNdB including for the intentional sideline-to-sideline asymmetries as implemented in the flight test by flying the aircraft with only one engine at power. Considerable progress has been shown here in the continuing effort to advance the fidelity of NASA aircraft noise prediction capabilities for subsonic aircraft flight acoustics, modern transport aircraft and future aircraft concepts.

aircraft system noise prediction↗