An Analysis of the Loads on and Dynamic Response of a Floating Flexible Tube in Waves and Currents

Abstract

Proposed offshore structure designs for algal production using wastewater may incorporate floating flexible tubes. This study includes an extensive set of physical modeling experiments to investigate the loads on and dynamic response of these tubes in waves and currents. The physical modeling approach involved designing and building an approximately 1:4 scaled representation of a potential design. Experiments were conducted with the model in the 37-meter tow/wave tank in Hydromechanics Laboratory at the United States Naval Academy. Several combinations of model tests were performed in scaled waves and currents at tube fill levels of 50% and 95%. Several of the tow tests done in the tank, representing oceanic currents, were validated with computational fluid dynamics. Along with the time series drag results, the physical modeling experiments that included both regular and random waves were analyzed to produce linear transfer functions for both heave and force. An assessment of these data sets indicated that the flexible floating tube response generally followed the wave forcing at the middle wave frequencies. For both fill levels, the response of the forward end of model increased with wave frequency while the response of the rear end of the model remained rather consistent across the frequencies tested. The results did not indicate a significant difference in dynamic response when the model was tested in both waves and current. The average attachment loads, however, were higher when the model was tested in waves and a current than in waves only.

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Document Details

Document Type
Technical Report
Publication Date
May 09, 2014
Accession Number
ADA604779

Entities

People

  • Grant N. Genzman

Organizations

  • United States Naval Academy

Tags

Communities of Interest

  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Attachment
  • Computational Fluid Dynamics
  • Computational Science
  • Construction Materials
  • Data Sets
  • Dynamic Response
  • Fluid Dynamics
  • Frequency
  • Froude Number
  • Measurement
  • Mechanics
  • Model Tests
  • Reynolds Number
  • Test Methods
  • Transfer Functions
  • United States
  • United States Naval Academy

Readers

  • Combustion Dynamics and Shock Wave Physics.
  • Computational Fluid Dynamics (CFD)
  • Marine Hydrodynamics