Measuring acoustic surface impedance of rough water: experimental design and modeling
Abstract
The goal of this research is to measure and model acoustic surface impedance of rough water. Understanding and modeling how sound propagates over rough surfaces is relevant for predicting sound pressure levels at sea and shore caused by noise sources at sea in real time. The results of this research aim to improve numerical tools used to predict the detectability of Naval vessels at sea and thus to preserve and increase the safety of personnel and equipment during stealth maritime operations. Specifically, the PIs have been involved in modeling and measurement of acoustic propagation over distances rangingfrom hundreds of meters to several kilometers.To date, the effort has focused on the development of a robust mathematical model of acoustic transmission loss given current atmospheric and weather conditions. However, one of the challenges is to make real time predictions when ranges of interest are on the order of several kilometers because modeling sea roughness requires substantial computational resources. One of the strategies that can be used to overcome this computational limitation is to replace the sea surface roughness with an equivalent surface impedance. This substitution can decreasethe computational time by orders of magnitudes, making a real time prediction possible. The proposed research aims to measure and model the acoustic surface impedance of water with roughness typical of different sea states. This aim canbe achieved by performing ANSI/ASA tests for outdoor surface impedance measurement on a controlled sea state environment. The Maneuvering and Seakeeping Basin (MASK) at Naval SurfaceWarfare Center (NSWC) Carderock, Bethesda, Maryland is capable of producing suchrepeatable, controlled environments. The knowledge of the equivalent surface impedances of several sea states will provide essential information for real time predictions of sound propagation over water.The PIs# are committed to involve students in meaningful research endeavors to better prepare them for success in graduate study or professional practice in many DoD-related paths. This work will also serve to support development of graduate courses in numerical methods in acoustics.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Apr 12, 2023
- Source ID
- N000142312352
Entities
People
- Diego Turo
Organizations
- Office of Naval Research
- The Catholic University of America
- United States Navy