Pure and aerated water entry of a flat plate
Pure and aerated water entry of a flat plate
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DOI：
10.1063/1.4940043
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发表时间：
2016-01
影响因子：
4.6
通讯作者：
Zh. H. Ma;D. Causon;L. Qian;C. Mingham;T. Mai;D. Greaves;A. Raby
中科院分区：
文献类型：
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作者：
Zh. H. Ma;D. Causon;L. Qian;C. Mingham;T. Mai;D. Greaves;A. Raby
本文介绍了一个刚性的方形平板进入纯水和充气水的实验和数值研究。着重介绍了平板砰击载荷的测量和计算。实验研究是在普利茅斯大学海岸实验室的海洋盆地中进行的。本数值方法扩展了二维水动力程序，以计算三维水动力冲击问题。数值模型计算的结构上的冲击载荷与实验室测量比较好。结果表明，冲击载荷具有明显的特征，包括（1）具有高压峰值的冲击载荷，（2）与接近饱和蒸汽压的非常低的亚大气压相关的流体膨胀载荷，（3）与超大气压相关的不太严重的二次再加载。还公开了引入水中的曝气可以有效地减小平板上的局部压力和总力。在水中1.6%的充气量下，板上的峰值冲击载荷可以减少一半甚至更多。同时，掺气可以延长冲击载荷的使用寿命，并且冲量的变化对掺气率的变化不像峰值载荷那样敏感。
This paper presents an experimental and numerical investigation of the entry of a rigid square flat plate into pure and aerated water. Attention is focused on the measurement and calculation of the slamming loads on the plate. The experimental study was carried out in the ocean basin at Plymouth University’s COAST laboratory. The present numerical approach extends a two-dimensional hydro-code to compute three-dimensional hydrodynamic impact problems. The impact loads on the structure computed by the numerical model compare well with laboratory measurements. It is revealed that the impact loading consists of distinctive features including (1) shock loading with a high pressure peak, (2) fluid expansion loading associated with very low sub-atmospheric pressure close to the saturated vapour pressure, and (3) less severe secondary reloading with super-atmospheric pressure. It is also disclosed that aeration introduced into water can effectively reduce local pressures and total forces on the flat plate. The peak impact loading on the plate can be reduced by half or even more with 1.6% aeration in water. At the same time, the lifespan of shock loading is prolonged by aeration, and the variation of impulse is less sensitive to the change of aeration than the peak loading.