楔形物体在静水与波浪中自由入水砰击试验研究

Experimental study on free fall slamming of wedge-shaped objects under still water and waves conditions

通过自由落体的入水方式,分别在静水和规则波中开展了两种不同横剖面的曲面楔形体入水砰击问题试验研究。使用高速摄像系统记录楔形体入水过程流场演变和运动特性,采用加速度传感器和压力传感器进行数据的动态采集。试验结果表明,在静水中入水时,外凸剖面楔形体入水砰击后模型两侧的射流飞溅比反曲剖面更剧烈,而在楔形体前端的水面以下部分形成的气腔更小;在规则波中入水时,对于相同模型,在波峰和上跨零点相位下模型入水砰击后两侧的射流飞溅比在波谷相位更剧烈。相同工况时,反曲剖面模型所受砰击的加速度峰值和压力峰值更小;在相同的入水速度下,对于相同模型,波浪载荷和砰击载荷的共同作用会使模型所受砰击压力显著增大。

The slamming problem of the wedge with two different cross-sections in still water and wave was studied by using gravity free-falling method.The high speed camera system was used to record the flow field evolution and motion characteristics in the process of water entry.Acceleration and pressure sensors were used for dynamics data acquisition.The experiments results show that the jet splashing produced by the convex cross section wedge is more intense than the retro-flexion profile under still water condition.Meanwhile,the air cavity area produced in the underwater part of the model front is smaller.However,for the same test model under regular wave condition,the jet splashing of wave crest and zero crossing point phase are more intense than wave trough.Under the same condition,the slamming acceleration peak and pressure peak by the retro-flexion profile wedge are smaller than the convex profile model.Furthermore,the slamming pressure significantly increases due to the coupling effect of the wave load and the slamming load under the same water entry velocity.