Aeroacoustics of High-Speed Jet Impingement Navy SBIR FY2010.2 Sol No.: Navy SBIR FY2010.2 Topic No.: N102-133 Topic Title: Aeroacoustics of High-Speed Jet Impingement Proposal No.: N102-133-0356 Firm: Combustion Research and Flow Technology, Inc. 6210 Kellers Church Road Pipersville, Pennsylvania 18947-1020 Contact: Neeraj Sinha Phone: (215) 766-1520 Web Site: www.craft-tech.com Abstract: The noise from the turbulent, hot, supersonic jets at take-offs and landings dominates noise emanating from other powerplant components and has significant safety implications for launch personnel, as well as by the integrity of the structural components of the deck itself. With the impending induction of the JSF/F-35B into the US Navy in the near-future, concerns regarding noise emissions have taken added prominence. Unique to the JSF/F-35B is the requirement for it to operate in short takeoff and vertical landing (STOVL) mode on smaller ships, with the exhaust nozzle being vectored vertically downwards to produce lift. Jet impingement on the deck gives rise to resonant tones that are produced by a powerful acoustic feedback loop formed between the ground plane and trailing edge of the exhaust nozzle via the ambient medium. Similar noise issues also exist with regards to exhaust impingement on the jet blast deflector (JBD) on carriers. CRAFT Tech and Purdue University will extend and demonstrate an innovative high-fidelity LES method towards characterization of the noise sources associated with high-speed impinging jets. The farfield noise emissions will be obtained with integral techniques that will be extended for jet impingement. The model will be validated against laboratory data. Benefits: The jet noise modeling/attenuation technology is of direct relevance to existing and future platforms. The technology developments proposed are also of extreme relevance to commercial aviation with regards to community noise concerns. The Federal Aviation Administration (FAA) and NASA represent additional avenues for commercialization of noise footprint model & mitigation concepts that will emerge from the proposed program. Noise mitigation techniques have generally proven effective in IR suppression. This provides additional commercialization opportunities since future combat air vehicles have placed a premium on stealth and low-observables (LO). Return