基于SPH/FEM方法的浅水冲击喷溅及其抑制结构研究

Research on the water spray generated by shallow water impact and its suppression structure by using the SPH/FEM method

物体浅水冲击会造成结构响应和自由液面的剧烈喷溅,以往的研究多集中在物体受水的冲击响应方面,而对浅水层受物体冲击引起的剧烈喷溅问题及其喷溅抑制结构的相关研究很少。本文基于SPH/FEM耦合方法对浅水冲击的液体喷溅特性开展研究。首先,计算了刚性长方体结构的冲击喷溅,与文献中准二维溅水试验结果进行了比较,将浅水喷溅分为初始喷溅、二次喷溅和底部射流三部分。分别研究了各部分喷溅的形成机理,指出二次喷溅由结构对水层的挤压和底部射流的能量传递共同引起,并分析了水深对二次喷溅的影响规律。其次,对喷溅抑制结构的机理做了数值研究,发现拱形翻边构型可以抑制初始喷溅,但不能有效降低二次喷溅。最后,提出了一种带凹槽和阻水边条的新型翻边构型,对二次喷溅具有更好的抑制效果。

The impact of an object dropping into shallow water would cause a structural response and severe spray.Previous research mainly focused on the response of the object caused by the water,while the works related to the water spray and its suppression structures are very inadequate.In this paper,the SPH/FEM coupling method is used to study the water spray generated by shallow water impact.Firstly,the water spray caused by rigid rectangular structure is simulated,through the comparison between the results and the previous experiments the spray is divided into three parts,i.e.the initial spray,the secondary spray and the bottom jet spray.Then the formation mechanisms of each part are investigated respectively,which indicate that the secondary spray is mainly caused by the interaction between the water squeezing of the structure and energy transforming of the bottom jet.The influence of the water depth on the spray is analyzed,which shows that the secondary spray increases with the decrease of water depth.Secondly,the mechanism of the water spray suppression structure is studied,which illustrates that the arched chine could suppress the initial spray,while it could not reduce the secondary spray effectively.Then a new type of chine with groove and water resistant edge is proposed,which would have a better effect,especially on the secondary spray.