Current noise prediction methods are ill-suited for the design of future nozzle geometries as they are either too computationally expensive or do not contain the necessary physics to adequately predict noise from desired nozzle types. As such, there is a need for innovative technologies and methods for noise prediction to enable acoustic optimization of multi-stream, 3D nozzles to meet the noise goals for NASA’s N+2/N+3 aircraft. As part of the SBIR program, Spectral Energies in collaboration with University of California at Irvine (the team) proposed to develop a design tool for nozzles that include acoustics. During the course of the SBIR Phase I, the team has demonstrated a viable method for acoustic optimization of nozzles relevant to N+2/N+3 aircraft using RANS based methods. This method was demonstrated to optimize the thickness of the third-stream for reduced noise production. These results were verified experimentally and computationally. During Phase II, the team will continue to improve the optimization methodology by incorporating more first principle physics into the noise model and including more variables that can be used to optimize the nozzle for acoustics, integration/feasibility, and performance. The team anticipates that the design tool developed under this program will be at TRL 6.
The development of this design tool will be critical to the success of NASA’s ARMD focus area of “innovation in commercial supersonic aircraft” and help meet the goals of N+2 and N+3 aircraft. We believe that this technology is directly relevant to NASA’s Advanced Air Vehicle Program (AAVP). Incorporating our proposed design methodology into NASA’s toolbelt will allow for the development of advanced nozzles relevant to supersonic commercial aircraft that can meet the noise requirements of the International Civil Aviation Organization (ICAO).
Aircraft noise is also an issue for DoD aircraft. The Office of Naval Research has funded multiple projects under its Jet Noise Reduction (JNR) program to develop methodologies for noise reduction. Our proposed tool would be useful for DoD and aerospace industry to develop quieter nozzles for future military and commercial aerospace vehicles.