Hydrodynamic regimes and drag on horizontally pulled floating spheres

We use high-speed imaging to investigate the movement of a floating sphere pulled horizontally along water surface. The model is 10 cm in diameter and has half density resulting half-submerged static sphere. By varying pulling force, we flow dynamics subcritical Reynolds number range, Re ≈ 2 × 104 105. characterize three hydrodynamic regimes with increase which refer as: low Froude number, Fr < 0.6, intermediate, 0.6 1.2 high > regimes. In regime, moves little disturbance surface drag close on fully submerged intermediate pronounced wave pattern developed together dipping below level leads an force. Based potential approximation for downward force moving surface, derive semiempirical relation as function number. Finally, switches mode periodic surfacing above vertical motion portrays decrease average