Data concerning the hydrodynamic advantages of arching sea stars modeled in a hydraulics flume.

Data collection method:

The experimental work was undertaken in a unidirectional flow channel measuring 7.50 m long and 0.30 m wide. Flow rate was controlled using a pump and two depth-averaged flow velocities (flow velocity averaged over the entire depth of the water column) were investigated. These were 0.10 ms-1 and 0.25 ms-1 and corresponded to relatively “low” and "high” turbulence cases. A sluice gate located downstream of the experimental section was used to control the water depth, which was set at 0.15 m or 0.30 m during the experiment. Dye concentration was measured at four positions downstream of the model along the flume centreline using a Turner Designs C3 Submersible Fluorometer sampled at 1 Hz. A Nortek Vector Acoustic Doppler Velocimeter (ADV) was used to obtain direct point measurements of flow velocity through the flume cross-section, a distance 80 mm downstream of the model centre (Fig. 2). Measurements of all three velocity components (x – along-flume, y – cross-flume, z - vertical) were obtained for both depth-averaged flow velocities at 35 mm vertical intervals at three cross-flume measurement locations. Velocity data was recorded for a 15 second period at each instrument location.