ガスバブルに誘起される船体のwhipping

抄録

Underwater explosions cause gas bubbles. If gas bubbles are generated at deep underwater, expansion and contractions are repeated as they float to the surface. Expansion and contraction in gas bubbles in turn cause flow in surrounding areas, thus inducing ship hull whipping at the proximity of gas bubbles. In extreme cases, the whipping may generate much longitudinal bending stress on the ship hull. For the structural design of ship hull which is to be subject to gas bubbles, it is necessary that quantitative analysis of whipping-caused longitudinal bending stress be performed for evaluating ship hull structural strength. This paper describes the vibration analysis method using a simple beam model for the ship hull structure in order to perform numerical analysis of whipping. It also discusses a calculation method for the kinetic characteristics of a fluid during expansion and contraction of gas bubbles which induce whipping. In addition, effects of gas bubbles on whipping are examined by calculation.