Maneuvering rotorcraft noise prediction

This paper presents the unique aspects of the development of an entirely new maneuver noise prediction code called PSU-WOPWOP. The main focus of this work is development of a noise prediction methodology, which will enable the study of the aeroacoustic aspects a rotorcraft in maneuvering flight. It is assumed that the aeromechanical data (namely aircraft and blade motion, blade airloads) are provided as input data. This new noise prediction capability was developed for rotors in steady and transient maneuvering flight. Featuring an object-oriented design, the PSU-WOPWOP code allows great flexibility for complex rotor configuration and motion (including multiple rotors and full aircraft motion). The relative locations and number of hinges, flexures, and body motions can be arbitrarily specified to match any specific rotorcraft. An analysis of algorithm efficiency was performed for maneuver noise prediction along with a description of the tradeoffs made specifically for the maneuvering noise problem. Noise predictions for the mainrotor of a rotorcraft in steady descent, transient (arrested) descent, hover and a “pop-up” maneuver are demonstrated.