Advances in Modeling and Simulation of Rotorcraft Noise and Associated Impacts on Survivability

摘要

The acoustic signature of a rotorcraft is often the primary means of detection and identification by enemy forces in the modern battlespace. Additionally, this detection is often accomplished without the need for the sophisticated sensing equipment required for other signature components. While this vulnerability has existed for many generations of rotorcraft, the tools for predicting the acoustic signature and understanding its impact on mission survivability have lagged in development. This is partially due the need for development of multidisciplinary knowledge and capability to predict the aerodynamic performance, structural dynamic response, near-field acoustic character, far-field atmospheric propagation and human perception as well as the historical lack of required computational resources. The advent of cheaper and more ubiquitous computational resources at the all levels in the rotorcraft community alleviated the later issue and left the need for a significant investment to address the former. Approximately four years ago, DARPA made this investment and identified teams of researchers guided by an advisory panel made up of industry and government experts aimed at developing the required assets. The DARPA funded Helicopter Quieting Program was initiated to focus on developing a suite of tools appropriate for use by the designer to predict the acoustic signature of rotorcraft. In the last year, the focus was expanded to leverage the signature prediction capabilities and develop tools appropriate for the mission planner and warfighter that enable visual analysis of the impact of signature change on survivability and operational effectiveness. The end product of this effort was three tool suites, verified using experimental data, capable of predicting the aerodynamic performance and acoustic signature of modern main rotors and the tools necessary to show the impact of signature changes on the mission effectiveness of the vehicle.