NASA SBIR 2008 Solicitation

SMALL BUSINESS CONCERN (Firm Name, Mail Address, City/State/Zip, Phone)
Hersh Acoustical Engineering, Inc.
22305 Cairnloch Street
Calabasas, CA 91302 - 5875
(818) 224-4699

PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
Alan Hersh
haeash@charter.net
22305 Cairnloch Street
Calabasas, CA 91302 - 5875
(818) 224-4699

Expected Technology Readiness Level (TRL) upon completion of contract: 4

TECHNICAL ABSTRACT (Limit 2000 characters, approximately 200 words)
An aeroacoustic computational code based upon a numerical solution of the full Navier-Stokes equations will be developed to provide a deep understanding of the physical behavior of resonator liners exposed to intense sound and boundary-layer grazing flow. The code computes the entire flow and acoustic field inside the flow duct. The user has the option to choose the flow Mach number, boundary-layer thickness, duct mode of incoming sound, frequency and SPL. For broadband sound, the user has the option to specify an incident noise spectrum. The code is designed to operate at both standard temperatures and very high temperatures.

A semi-empirical three-dimensional resonator liner impedance code will developed for resonators also exposed to intense sound and boundary-layer grazing flow. The liner empirical parameters will be calibrated with NASA furnished resonator test data. Because of its simplicity, it can be used to provide realistic liner geometries for sound propagation codes that are used in both NASA and industry to determine optimum wall impedances to control excessive sound generated in jet engines and other flow duct environments.

POTENTIAL NASA COMMERCIAL APPLICATIONS (Limit 1500 characters, approximately 150 words)
An aeroacoustic computer code will be developed capable of predicting the impedance of liners exposed to intense sound, high subsonic grazing flows and at high temperatures. This will provide an essential tool for the aircraft engine acoustic designers to understand how resonators behave in harsh engine environments. A 3-D liner impedance model will be developed capable of determining the incident sound pressure far-field face-plate distances from resonator orifices. This represents an initial step in improving our understanding of how to effectively use the Dean Two-Microphone impedance measurement method. This is especially important because the Dean method is one of the current benchmark standards used to measure the effects of grazing flow and SPL on the impedance of cavity-backed liners.

POTENTIAL NON-NASA COMMERCIAL APPLICATIONS (Limit 1500 characters, approximately 150 words)
An aeroacoustic computer code will be developed capable of predicting the impedance of liners exposed to intense sound, high subsonic grazing flows and at high temperatures. This will provide an essential tool for the aircraft engine acoustic designers to understand how resonators behave in harsh engine environments. A three dimensional liner impedance model will be developed and mated to a flow duct sound propagation code to provide the designer of HVAC centrifugal and axial with the necessary tools to design highly efficient sound absorbing HVAC centrifugal and axial products. This technology is capable of being ported, for example, to manufacturers of space heaters and other products requiring quiet airflows.

NASA's technology taxonomy has been developed by the SBIR-STTR program to disseminate awareness of proposed and awarded R/R&D in the agency. It is a listing of over 100 technologies, sorted into broad categories, of interest to NASA.

TECHNOLOGY TAXONOMY MAPPING

Aircraft Engines