The use of tip-jets to provide the torque to power rotor blades has long been considered as an alternate approach to a shaft-driven rotor system. However, large tip-jet exit velocities are needed to provide sufficient jet thrust to power the rotor; hence, these jets can generate very large noise levels when compared to the usual sources of rotating blade noise. This paper demonstrates a new approach to predict the noise from such a design. The prediction method uses a derivative of the SAE ARP876 (Revision D) code to compute the tip-jet noise and PSU-WOPWOP to compute the rotational noise. Noise predictions for the Fairey Rotodyne aircraft are compared with acoustic measurements to provide a limited validation of the noise prediction method. The prediction method is also demonstrated through a brief investigation of design constraints and their impact on the rotor noise levels.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Aerospace Engineering
- Mechanics of Materials
- Mechanical Engineering