Imaging of Hydrodynamic Field Around Submerged Objects Regular Wave and Tsunami Conditions

Abstract

Hydrodynamic particle movement under regular waves and tsunami wave are rarely studied due to its complicated sensors. This research is aimed at investigating flow fields around submerged structures due to regular waves and tsunami wave. A series of experiments were performed at Tsunami Flume Workshop Facility at Tsunami and Disaster Mitigation Research Center (TDMRC) of Universitas Syiah Kuala. The flume has 60 m in length, 2.5 m in width and 1.7 m in height. To model the both waves, a set of electrical paddle and sensors were placed at one end of the flume. This set of equipment is able to mimic any waveform model, in this case a regular wave with three scenarios and the 2004 Indian Ocean Tsunami wave scenario. A submerged structure was placed on the bed of the flume to model underwater structures. To capture the flow fields, we use a Laser Particle Image Velocimetry (PIV) Camera made in Seika. During the experiment, the results showed different vortex field for both simulations, regular wave and tsunami, generated in front of the submerged structure. Regular wave flow has maximum velocities of 0.5 m/s, 0.7 m/s, 0.9 m/s in each paddle amplitude change scenario. The flow field produces an anticlockwise vortex around the pipe with differents pattern. Tsunami wave flow velocity during the maximum amplitude phase is about 0.25 m/s with a complex vortex field around the pipe, a combination of clockwise and anticlockwise. This could be interpreted as more chaotic hydrodynamic fields around the submerged structures under regular wave and tsunami conditions.