Cycle-to-cycle variations in the wave forces on horizontal cylinders.
Measurements of the wave forces on horizontal cylinders in laboratory waves are presented. The horizontal and vertical force components are examined together so that variations and limitations in the traditional Morison methods can be identified. Average magnitudes of the wave forces and the force transfer coefficients are compared to wave by wave values for up to ten consecutive wave cycles in an effort to resolve conflicting reports of cycle to cycle irregularities in harmonic flow induced forces. The observed influences of different water particle orbit shapes are presented as well. The experinemts, necessarily at low Reynolds number, provide results that encompass a wide range of wave/cylinder conditions. (from authors' abstract)