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Full-Text Articles in Mechanical Engineering
Acoustic Localization Techniques For Application In Near-Shore Arctic Environments, Miles B. Penhale
Acoustic Localization Techniques For Application In Near-Shore Arctic Environments, Miles B. Penhale
Dissertations, Master's Theses and Master's Reports
The Arctic environment has undergone significant change in recent years. Multi-year ice is no longer prevalent in the Arctic. Instead, Arctic ice melts during summer months and re-freezes each winter. First-year ice, in comparison to multi-year ice, is different in terms of its acoustic properties. Therefore, acoustic propagation models of the Arctic may no longer be valid. The open water in the Arctic for longer time periods during the year invites anthropogenic traffic such as civilian tourism, industrial shipping, natural resource exploration, and military exercises. It is important to understand sound propagation in the first-year ice environment, especially in near-shore …
Multi-Modal And Short-Range Transmission Loss In Ice-Covered, Near-Shore Arctic Waters, Miles B. Penhale
Multi-Modal And Short-Range Transmission Loss In Ice-Covered, Near-Shore Arctic Waters, Miles B. Penhale
Dissertations, Master's Theses and Master's Reports
In the past century, extensive research has been done regarding the sound propagation in arctic ice sheets. The majority of this research has focused on low frequency propagation over long distances. One of the most commonly used excitation methods for air-ice-water layers has been explosives. However, environmental regulation has become more stringent, disallowing the use of almost all explosive excitation types. Due to changing climate conditions in these environments, new experimentation is warranted to determine sound propagation characteristics in, through, and under thin ice sheets, in shallow water, over short distances. In April, 2016 several experiments were conducted approximately 2 …
Evaluation Of Angular Distribution Of Incident Field At The Transmission Loss Window In Michigan Tech’S Reverberant Chamber, Abhishek Thyagarajan
Evaluation Of Angular Distribution Of Incident Field At The Transmission Loss Window In Michigan Tech’S Reverberant Chamber, Abhishek Thyagarajan
Dissertations, Master's Theses and Master's Reports
Transmission Loss prediction accuracy is highly dependent on a good understanding of the angular distribution of incident field on the panel. Traditionally, the incident field has been assumed to be either completely random (equal probability of incidence at all angles from 0° - 90°) or field incidence (where the field is assumed to be completely diffuse between 0° - 78°). Studies1-3 have shown that these models are not completely representative of the incident field. This incident field is studied in the Michigan Tech Transmission Loss suite using two different methods in this study; beamforming and acoustic intensity. The beamforming method …