EXPERIMENTAL INVESTIGATION OF HYDRODYNAMIC COEFFICIENTS ON VERTICAL CYLINDER SUBJECTED TO SHORT-CRESTED WAVES

Morison et al. proposed a formula to estimate the wave forces generated from unidirectional
regular waves in assumption that the presence of the slender body as an
object did not affect to the characteristic of the wave field. It assumes that the force
derived from this effect is composed of inertia forces and drag forces added together.
These components require the knowledge of an inertia coefficient and a drag
coefficient which are determined experimentally. Practically, uni-directional or the
long-crested waves are commonly used in the design of offshore structures for
estimation of wave forces exerted to the structure. Instead of regular waves, shortcrested
waves are much better model to represent the waves generated by wind in
oceans and short-crested waves have many different properties compared to longcrested
plane waves. Hydrodynamic force coefficients on rigid vertical cylinder was
investigated on an experiment of hydrodynamic coefficient induced by long crested
wave. However, to the author’s knowledge, no-one seems to have discussed the
experimental investigation of hydrodynamic coefficients on rigid vertical cylinder in
short-crested waves