考虑内流场的水下爆炸下瞬态流固耦合效应研究

Investigation of Fluid-structure Interaction with Effect of Internal Fluid Cavitation and Reloading under Underwater Explosion

对水下爆炸下含水双层板的内流场瞬态流固耦合效应进行研究。用二阶双重渐进近似方法(DAA2)分析外流场与结构的流固耦合,用自行开发的空化水锤声学元(CHAFE)模拟双层板间的内流场与结构的流固耦合。空化水锤声学元包括两个部分:以空化声学元(CAFE)描述包括空化效应的非线性流场效应,以改进的非线性间隙元(GAP)描述内流场与板结构的空化及其再加载效应。采用ABAQUS有限元程序的水下爆炸分析模块对空化声学元进行了验证,表明空化声学元是合理可信的。最后,对含水双层板在水下爆炸作用下的动态响应进行瞬态流固耦合效应分析,给出了冲击波作用下内流场与双层板流固耦合作用过程及其特征,描述了空化、水锤发生过程,并分析了内流场对结构动态响应的影响。

The fluid-structure interaction( FSI) of double plate with water subjected to underwater explosion is researched. The doubly asymptotic approximations( DAA) method is used to analyze the outer fluid-structure interaction( FSI). A cavitation acoustic hammer finite element( CHAFE) is developed to simulate the internal FSI effect. Two modules are included in CHAFE: cavitation acoustic finite element( CAFE) and improved GAP element. CAFE is used to describe the non-linear fluid field effect,and the improved GAP element is used to describe the cavitation of fluid and structure and its reloading effect.The UNDEX module in ABAQUS software is used to verify the proposed method. The reloading effect of the local cavitation of double-plate structure filled with liquid under underwater explosion is numerically calculated,and three reloading models are compared. The process of local cavitation,reloading development and its characteristics are obtained.