NASA Langley Research Center, Industry Assistance Office, MS 144 Hampton, Va. 23681-0001

A -- NOISE REDUCTION RESEARCH FOR ADVANCED SUBSONIC TRANSPORTS POC Linda P. Fitzgerald, Industry Assistance Office, (804) 864-2461. NASA Langley Research Center has a continuing program supporting development of advanced aircraft noise prediction and control technology for the U.S. aircraft industry. Potential sources for these specific requirements in support of the Advanced Subsonic Technology Noise Reduction Program milestones are being sought who have: expertise in acoustic and aerodynamic testing of model airframes and their components, including high-powered ducted fan models, experience in the collection, reduction and analysis of microphone array data for the purposes of in-duct modal measurement, farfield radiation mapping, and airframe and engine noise source localization, world class facilities for acoustic measurements in the geometric farfield from model airframes and components with cross-flow dimensions as large as 12 feet and with operating speeds up to Mach 0.25 and with provisions for testing powered models with continuous drive air mass flow up to 30 lbm/sec, a high-powered ducted fan model of at least 18'' diameter with provisions for running with or without stators and support struts, with or without boundary layer suction on the inlet duct, variable rotor to stator axial spacing, rotor tip clearance control, variable fan loading, with adequate in-duct instrumentation and processing capability to measure axial and circumferential wavenumber spectra for broadband and tonal acoustic fields with energy in all propagating modes at frequencies up to 5 times the blade passage frequency, and optical glass window to permit use of fiber- optic laser Doppler velocimetry between the rotor and stator, experience in large-scale wind tunnel testing of propulsion airframe interaction effects on noise from a large scale configuration representative of a current subsonic transport in the high-lift mode capable of modeling details of the wing and engine geometry to quantify the change in airframe noise due to the presence of the engine exhaust and to quantify the change in the jet noise due to the presence of the wing high-lift flowfield, a high-bypass-ratio dual flow jet simulator for study of jet noise phenomena including influence of freestream flow at angle of attack, large high temperature dual flow jet simulation rig for jet noise studies for subsonic and supersonic transports, experience in designing and manufacturing nacelle liners with lining features such as variable depth buried septum double-layer linings, experience in the design of nacelle noise suppression hardware, capability to measure non-uniform impedance distributions for liners built to scales of 0.2 to 1.0 of full scale with grazing flow up to Mach 0.5 and grazing incidence sound at frequencies up to 3kHz, capability to test transmission loss characteristics of full scale fuselage barrel sections up to wide body class aircraft in a fully anechoic environment, access to large database of flight test data on a broad class of commercial aircraft relating to exterior flow, boundary layer pressure loading and jet noise near-field loading, access to large data bases for detailed airframe noise characteristics of current subsonic transports including wing and high-lift systems designs, and demonstrated expertise in extracting meaningful acoustic data from reverberant and noisy environments such as hard wall wind tunnels. This procurement will provide for a maximum effort of approximately 100,000 hours over a 3 year period. Interested offerors having the required specialized capabilities to meet the above requirements should submit a capability statement of 10 pages or less indicating the ability to perform all aspects of the effort described herein and at least one reference from a previous contract, preferably from a Government agency. (Please provide a contract number, names of cognizant contract personnel, and an applicable telephone number on the contract). Offerors must identify the equipment which they will furnish to perform the work. This synopsis is for information and planning purposes and does not indicate a commitment by the Government nor that the government will pay for information solicited. Respondents will not be notified of the results of the evaluation. Respondents deemed fully qualified will be considered in any resulting solicitation for the requirement. Firms responding should indicate whether they are a socially or economically disadvantaged business firm, a small business, an 8(a) and/or women-owned business. The Government reserves the right to consider a small business or 8(a) set-aside based on responses hereto. All responses shall be submitted to the NASA Langley Research Center, Industry Assistance Office, Mail Stop 144, Hampton, VA 23681-0001 within 14 days from the date of publication of this announcement. In responding reference SS255. (0074)

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