Accession Number : ADA604779


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


Descriptive Note : Trident Scholar Project rept. no. 427


Corporate Author : NAVAL ACADEMY ANNAPOLIS MD


Personal Author(s) : Genzman, Grant N


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a604779.pdf


Report Date : 09 May 2014


Pagination or Media Count : 82


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.


Descriptors :   *DYNAMIC RESPONSE , *FLEXIBLE STRUCTURES , *FLOATING BODIES , COMPUTATIONAL FLUID DYNAMICS , DRAG , FREQUENCY RESPONSE , HEAVING , HYDRODYNAMICS , HYDROMECHANICS , LOADS(FORCES) , MODELS , OCEAN CURRENTS , TIME SERIES ANALYSIS , TRANSFER FUNCTIONS , TUBES , WATER WAVES


Subject Categories : Fluid Mechanics


Distribution Statement : APPROVED FOR PUBLIC RELEASE