An experimental investigation of the characteristics of a cylinder interacting with waves and flow in the dominant-load regime. (August 2019)

• Record Type: Journal Article
• Authors: Wu, Hao; Lin, Yan
• Is Part Of: Applied ocean research. Volume 89(2019)
• Page Start: 154
• Page End: 175
• Publication Date: 2019-08
• Subjects: Cylinder -- Wave -- Flow -- Dominant -- Response -- Frequency -- Magnitude; Ocean engineering -- Periodicals; 620.416205
• DOI: 10.1016/j.apor.2019.04.009
• Languages: English
• ISSNs: 0141-1187

Abstract

Abstract: We describe in this paper the experimental investigations of the interaction of a bottom-pivoted vertical cylinder with water waves and flow, to determine the dominant-load-regime map by application of response step functions and response RAO. A rigid circular cylindrical mass-damper-spring oscillator system is investigated in regular waves and uniform flow to determine the response characteristics in the frequency domain. Interaction with waves dominates in the high frequency range f* = f osc / ω v = 0.862–1.547, with magnitude in the range of 0.1 rad. On the other hand, interaction with flow dominates at lower frequency range, f* = 0.442–0.862, with magnitude in the range of 0.01 rad. These are caused by the non-overlap peak positions of the magnitude response in waves and flow due to the change in added mass of the cylinder moving in different types of fluid loads. The frequency f* = 0.862 is the point where the dominant factors are transferred. The location of separation points determines the pressure distribution to induce the added mass changed. Separation positions determine the magnitude response, but do not determine the configuration of response RAO. That allows to enhance or reduce the magnitude response of the cylinder by taking advantage of the dominant-load-regime map in the frequency domain.