ANALYSIS OF WAVE-INDUCED FORCING ON A SUBMERGED BODY AT VARIOUS PITCH ANGLES
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Authors
Hermsen, Bennitt L.
Subjects
submerged body
cylinder
waves
Unmanned Underwater Vehicles
UUVs
pitch angle
cylinder
waves
Unmanned Underwater Vehicles
UUVs
pitch angle
Advisors
Kwon, Young W.
Klamo, Joseph
Date of Issue
2020-06
Date
Publisher
Monterey, CA; Naval Postgraduate School
Language
Abstract
This experiment aimed to quantify the effect of pitch angle on the linear and nonlinear wave-loading of a submerged, cylindrical body. The lower-frequency nonlinear loads that occur in a multi-component seaway were also investigated in greater detail for the zero-pitch case. Unmanned Underwater Vehicles (UUVs) are of increasing interest for use in littoral zones so performance parameters need to be well defined for better design and control. A model was subjected to single- and two-component wave trains for pitch angles between -15° and +15° at a depth of 1.5D (model diameter). The results show a negligible difference in vertical force and pitch moment for this range of pitch angles. There was a small increase in drag force at +/-15°. The two wave tests validated the use of superposition for predicting linear loads in a multi-component seaway. The smaller low-frequency, nonlinear drag and vertical forces have similar trends with a maximum around a 0.4 Hz frequency difference. The nonlinear pitch moment increases with frequency difference over the range tested. The low-frequency nonlinear loads show a dependence on frequency difference.
Type
Thesis
Description
Series/Report No
NPS Outstanding Theses and Dissertations
Department
Mechanical and Aerospace Engineering (MAE)
Organization
Identifiers
NPS Report Number
Sponsors
Funder
Format
Citation
Distribution Statement
Approved for public release. distribution is unlimited
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.