基于船模试验大外飘船型入水问题的分析

Analysis of water entry for large flare ship based on model experiment

在拖曳水池对四条艏部线型不同的姊妹船进行了分段模型砰击试验,通过对模型砰击压力及运动的测量,提出针对外张砰击的压力持续时间和砰击系数的计算公式,提出的砰击时间计算公式更能够反映出不同位置处和不同海况下的差异,而基于砰击系数计算公式预报的压力峰值与试验结果也比较一致.引入外张度这一概念来衡量艏部线型变化对砰击压力的影响,结果表明:在低海况下,四条船测得的结果很接近,这说明此时线型的变化对砰击带来的影响不大,但随着海况越大,线型的变化对砰击带来的影响也越大.

The segment ship model tests of four sister vessels with different bow linetype were carried out at the test tank.From the measurement of slamming pressure,movement of ship model,the expression of time distribution and flare slamming coefficient of the hull were obtained.From the comparison,it is shown that the proposed expression of time distribution can reflect the difference among the different positions and the different sea conditions better,and based on the presented flare slamming coefficient,the computational results of slamming pressure are in good agreement with experimental results.Finally,degree of flare was introduced to study the effort of change of bow line type on slamming pressure,and results show that for low sea state,the measured results of the four ships are very close,and the change of bow line type has little effect on the slamming,but for high sea states,bow line type has an increasing influence over the slamming pressure.