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Brenda Henderson

Publications and source records attributed to Brenda Henderson.

At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2023

Acoustics Technical Working Group and UAM Noise Working Group Proceedings

The NASA Acoustics Technical Working Group Meeting originally started as a program planning meeting in 1992 and has grown through the years. The purpose of these biannual meetings is to foster communication and collaboration among NASA researchers and their university, industry, and government colleagues on activities and work of current and future mutual interest. The NASA-led Urban Air Mobility (UAM) Noise Working Group (UNWG) Meeting began in 2018 as a one-day meeting immediately following the Acoustics Technical Working Group Meeting. The UNWG utilizes four subgroups that conduct regular meetings throughout the year to focus on challenges facing UAM vehicles for community noise and acceptance. The four subgroups coordinate research for development of noise prediction tools/noise reduction technologies, ground and flight test methods, human response and metrics, and regulations and policy (led by the FAA). This work is a compilation of the presentations given at ATWG/UNWG Fall 2022 held in person and via Teams at NASA Glenn Research Center. All NASA content was previously submitted through STRIVES for public presentation. This is merely a compilation. Non-NASA content has permission to distribute. Slide 208 video is included in the Available Downloads as Medial.MOV.

Advanced Air Mobility↗
NASA NTRSDate not supplied

Status of Learjet Flight Test and Jet Noise Modeling

The status of a future jet-noise test using a Lear 25 aircraft is provided. The intent of the test is to provide data for comparisons with scale-model data acquired in the Aero-Acoustic Propulsion Laboratory (AAPL). Preliminary results from a jet-noise model based on data acquired in AAPL are also presented.

Brenda Henderson↗
NASA NTRSDate not supplied

Progress on Electric Motor Noise Modeling

Progress toward the development of a motor noise model for system type studies is presented. The presentation focuses on efforts to model the motor shell vibrations and the resulting acoustic radiation. Finite element and experimental modal analysis results for a 4 kW motor are presented and compared. An analytical model for the acoustic radiation is presented.

Urban Air Mobility↗
NASA NTRSDate not supplied

Preliminary Analysis of Moog SureFly Electric Motor Noise Measurements

The results of acoustics measurements on the installed and unloaded axial-flux electric motor used on the Moog SureFly® vehicle are presented and compared to previous ground run-up measurements for the vehicle. The directivity of the motor was found to be significantly different than that obtained for much smaller 2 – 4 kW radial flux motors tested previously in the Acoustic Test Laboratory at NASA Glenn. Significant radiation occurred at shaft orders between 17 and 20 and at order 30. Peak radiation levels occurred near the highest speeds expected for the vehicle. There was an indication that some of the tones appearing in the spectra obtained in the previous ground run-up test were associated with the motor.

Urban Air Mobility↗
NASA NTRSDate not supplied

Update on Electric Motor Noise

Electric motors like those used in concept Advanced Air Mobility vehicles generate noise relevant to the acoustic profile of those vehicles. This work presents ongoing efforts to study, understand, and predict the noise generated by these types of motors. Efforts to perform experimental and simulation investigations of motor vibration modes are presented. Then recent acoustic measurements of operating motors and the resonant tones they generate is discussed. Lastly an update of ongoing efforts to measure real world vehicles is provided.

Electric motor noise↗
NASA NTRSDate not supplied

Learjet Flight Test Update

The presentation provides an update on progress towards an acoustic test with a Lear 25 aircraft. The intent of the test is to acquire data that will be used to determine the ability to predict jet noise for future supersonic aircraft at takeoff from scale-model data acquired in wind tunnels. Flight and instrumentation details are provided for the flight test planned for 2022.

Electric Motor Noise↗
NASA NTRSDate not supplied

Learjet Test Update

An update on the Learjet acoustic flight test was presented. The intent of the effort was to acquire flight data for the development of flight corrections to scale-model data. The flights were completed on September 8, 2022. Weather measurements were acquired with a combination of an instrumented drone and a ground based LiDAR system. Acquisition of comparative scale-model data will be completed on October 7, 2022.

jet noise↗
NASA NTRSDate not supplied

Moog SureFly® Hover Test Update

An update on the Moog SureFly vehicle acoustic hover test is presented. The intent of the effort was to acquire data that will be used to identify the acoustic far-field for the vehicle and the importance of electric motor noise relative to other sound sources for hover. The data will also be available to assess sound levels for future vertiports. The flights were completed in June 2022 at the Cincinnati Municipal Airport – Lunken Field.

jet noise↗
NASA NTRSDate not supplied

Single-Stream Empirical Jet-Noise Models Based on Scale-Model Data

Accurate single-stream jet-noise models for hot jets in flight are necessary for predicting noise of future commercial supersonic aircraft at takeoff. Previous comparisons between flight data and existing models have shown unacceptably large errors in the predictive tools. In the current effort, acoustic data were acquired in the Aero-Acoustic Propulsion Laboratory at the NASA Glenn Research Center for a single-stream hot jet with a range of operating conditions and simulated flight speeds that include those expected at takeoff of commercial supersonic aircraft. Models are presented for the resulting shape functions used to estimate the average spectra derived from the appropriate scaling of the jet-noise data.

Acoustics↗
NASA NTRSDate not supplied

Status of Moog SureFly Hover Test and Progress on Noise Prediction Efforts

An update on the Moog SureFly vehicle acoustic hover test and predictions is presented. Data were acquired for a 15’ hover altitude. Preliminary predictions using CAMRAD coupled with ANOPP have been completed. The predictions are currently using a generic blade geometry. High resolution blade scans have been initiated for the same type of rotor as that used on the SureFly vehicle and the resulting coordinates will be implemented in future prediction efforts. Plans for a future hover test at higher altitudes are discussed.

jet noise↗
NASA NTRSDate not supplied

Development and Validation of an Initial Electric Motor Rotor Vibration Model

An overview of the development of a low fidelity prediction tool for electric motor rotor resonant modes and frequencies. These predictions are useful for the prediction of UAM motor noise during the design phase. Finite Element Analysis of motor rotors has led to the development of a parameterized model to predict these modes shapes. This has in turn allowed to a curve-fit based model from parametric sweeps. These curves can predict resonant frequencies and shapes for 1-5kW class motors without running a simulation.

acoustics↗
NASA NTRSDate not supplied

Moog S-250 Vehicle Hover Test Update

Acoustic measurements were made with the Moog SureFly vehicle in hover and for the vehicle performing a combined takeoff and landing maneuver. The objectives of the effort were to identify the far field, obtain data to construct a noise hemisphere for prediction tool validation, and to obtain out-and back data for use in perceived noise studies. Vehicle telemetry data and future plans for the acoustic analysis were presented.

Urban Air Mobility Noise↗
NASA NTRSDate not supplied

An Initial Electric Motor Rotor Vibration Model

Ongoing integration of outrunner brushless electric motors into drones and Advanced Air Mobility aircraft presents a need for accurate acoustic predictions derived from prediction of the motor rotor vibrations. In outrunner motors, the external rotor vibrates and drives the acoustic field. At resonant frequencies of the rotor, the rotor displacements will be the largest. The vibrations can lead to acoustic tones that are relevant to the overall acoustic design of these types of vehicles. This study performs a finite element analysis to assess the modes in two electric motor rotors. This model is then refined into a simple parameterized geometry that can make the same predictions for motors of the same class. A parametric sweep and least-squares-curve fit to the finite element analysis data results in a series of simple curves that can predict the mode shapes and frequencies that are likely to appear in this class of motors without the need for any simulation. The simulations are validated by comparison to acoustic and experimental modal-analysis data.

Electric Motor Noise↗