Fig. 1
From: Flutter to tumble transition of buoyant spheres triggered by rotational inertia changes
Experimental facility and spheres used in the present study. a A perspective representation of the measurement section of the Twente Water Tunnel (TWT) with the two camera experimental arrangement for tracking the trajectory and orientation of the buoyant spheres in turbulent flow (not to scale). b, c Cut-section schematics of the high and the low moment of inertia (MoI) spheres, respectively. The high MoI sphere is hollow. The low MoI sphere is constructed with a dense metallic core, which is held in the center using thin spokes as shown in c
