Rotorcraft Acoustic/Aerodynamics Analyses

The technical objectives of the present effort, over three SBIR phases, are to develop a far field wave propagation tool that will accurately predict the aeroacoustic characteristics of rotorcraft in the far field, a number of kilometers away, while accounting for the presence of irregular terrain, atmospheric and (approximate) ground absorption, temperature and density gradients in the atmosphere, and prevailing winds. This work is divided into three phases. Phase I focuses on implementing the present far field method and validating it for well documented thickness noise and BVI noise simulations for wind tunnel conditions. The Phase I option period involves extending the methodology to wave length dependent effects such as nonlinear wave steepening and accurate ground absorption. Phase II focuses on further validation of this methodology for rotorcraft for a variety of steady, descent, and maneuver operations while accounting for terrain and atmospheric effects. Phase III focuses on incorporating industry requirements and feedback into an industry standard methodology that includes simulation and visualization of rotorcraft acoustic propagation phenomena of interest to helicopter industries.