Experimental Assessment of Entanglement for an Unmanned Underwater Vehicle with an Open, Three-Bladed Propeller
Abstract
This thesis evaluates the entanglement of an unmanned underwater vehicle (UUV) propelled by an open, three-bladed propeller when operating in marine vegetation native to littoral environments. A tow tank populated with synthetic giant kelp and eelgrass was used to simulate an underwater environment. An early variant of a REMUS 100 UUV designed to conduct underwater surveillance was used for entanglement tests. Three different entanglement tests were conducted. A vegetation density and constant entanglement test, conducted bychanging vehicle steady-state speed and marine vegetation density, showed an increased entanglement risk for eelgrass and astern propulsion operations, and increased vegetation density. A lateral placement entanglement test, conducted by changing the marine vegetation location relative to the vehicle center line, showed an increase in entanglement risk for vegetation located close to the propeller and indicated a relationship between propeller diameter, vegetation location, and entanglement. A preliminary accelerating speed entanglement test, conducted by changing the vehicle speed at the propeller entry to a vegetation field, showed that as the ratio of vehicle speed at propeller entrance to steady-state speed decreased, the likelihood of an entanglement increased. Recommended future work includes entanglement testing for different UUV types, testing in the operating environment, and assessing devices or procedures intended to reduce entanglement risk.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 2020
- Accession Number
- AD1126929
Entities
People
- Katherine E. Irgens
Organizations
- Naval Postgraduate School