BRRC is a key member of the contractor team supporting community response tests as part of NASA’s Quesst mission. NASA is working with Lockheed Martin Skunk Works to design and build the X-59 research aircraft, which will demonstrate technology that reduces the loudness of sonic booms to a gentle thump. NASA will fly the X-59 over selected communities around the United States to evaluate community responses to low sonic booms. BRRC will support NASA during these community response tests as part of a contractor team led by HMMH. BRRC’s roles on the team are to plan the flight path of the X-59 to deliver the desired sonic boom metric, to predict and measure sonic boom metrics across each overflown community, and to estimate the sonic boom metric received by each participant in the community response survey. These results will enable NASA and other members of the contractor team to determine the dose-response relationship between the sonic boom metrics and the community response. Ultimately, these results may enable supersonic flight over land.

Currently, BRRC is working with NASA and other members of the HMMH-led contractor team in the planning stage for the community response tests. BRRC has developed novel algorithms to detect and classify low sonic booms in the presence of ambient noise (link) and to combine measured and predicted sonic boom metrics using a Kalman filter (link). Photo credit: NASA

BRRC is developing a jet blast estimation tool for airport operators to predict the jet blast velocities and temperatures produced by commercial and military aircraft. This research effort involves reviewing the literature for prior work on jet blast, developing and validating a computational model to predict jet blast, and implementing the model as a user-friendly software tool for airport operators. BRRC is performing high-fidelity CFD simulations of jet exhaust plumes and analyzing the salient physics from the simulations to develop the computational model. To validate the computational model, BRRC is deploying sensors to measure jet blast velocities and temperatures produced by commercial aircraft at airports. Finally, BRRC is implementing the computational model as a user-friendly software tool for airport operators to predict jet blast from commercial and military aircraft based on local conditions. Ultimately, the results of this project will enhance safety for airport personnel near jet aircraft.

BRRC was selected by the Agility Prime Program to inspect, process, and analyze the noise data collected from the April 2022 measurements of LIFT’s HEXA aircraft. Four microphones perpendicular to the flight path recorded continuously to capture the noise from three HEXA flyovers for two different payloads. BRRC identified and extracted the ascent, level fly-by, and descent portions of each flyover from each microphone recording using the vehicle’s tracking data. These events were then reviewed for quality and saved using a standard format (ANSI S12.75) which includes pertinent test and equipment information within an ASCII header. For each test condition, event, and microphone, BRRC computed the spectral time history as well as the average sound exposure level (SEL) and average A-weighted maximum sound level (LA,max). These data were delivered in a readable text file format that included the relevant test information. The results of BRRC’s review and analysis were summarized in a slide deck which was presented and delivered to the client. Photo Credit: Samuel King Jr, U.S. Air Force.

BRRC provided King County International Airport (KCIA) with advanced acoustic modeling for a proposed Laterally Displaced Approach (LDA). The analysis demonstrated the impact of over-water noise propagation on the proposed approach vectors. BRRC utilized the military noise model NoiseMap for this analysis, importing the flight operations from KCIA’s 2004 Part 150 study. Photo Credit: redlegsfan21 from Vandalia, OH

BRRC developed noise contours to evaluate impacts due to the Proposed Actions to operate the Lynx, XCOR’s commercial reusable launch vehicle, from Midland International Airport (MAF). The No Action Alternative noise contours were developed using a combination of FAA’s aviation noise model for civil aircraft and DoD’s NoiseMap program for military aircraft. The Lynx rocket sonic boom and noise modeling were performed using PCBoom and BRRC’s Launch Vehicle Acoustic Simulation Model (RUMBLE).