Efficient Method for Wet Modal Analysis of Cyclic Periodic Fluid/Structure Systems
Efficient Method for Wet Modal Analysis of Cyclic Periodic Fluid/Structure Systems
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DOI：
10.2514/1.j063264
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发表时间：
2023-11
期刊：
影响因子：
2.5
通讯作者：
C. Nie;Kang Wang;Yuming Mao;Qiang Gao
中科院分区：
文献类型：
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作者：
C. Nie;Kang Wang;Yuming Mao;Qiang Gao
本文提出了一种有效的方法来分析部分充液的立式周期循环贮箱的模态。通过引入附加质量矩阵来模拟流体对结构振动的影响。由于由边界元法形成的附加质量矩阵是完全填充的，所以当湿模态分析涉及大量湿单元时，它需要相当大的计算机内存。此外，密集的附加质量矩阵将破坏总质量矩阵的稀疏性，导致求解特征值问题的显著计算负担。基于流体/结构系统的循环周期性，证明了立式循环周期贮箱的附加质量矩阵也具有块循环性。因此，根据群表示理论，湿模态分析的原始特征值问题可以解耦为一系列独立的子问题。由于子问题的计算规模远小于原特征值问题的计算规模，该方法可以显着降低计算成本。数值算例表明，该方法能够高精度、高效率地求解周期性流体/结构系统的模态分析问题。
In this paper, we propose an efficient method for the modal analysis of vertical cyclic periodic tanks partially filled with liquid. The fluid effect on the vibration of the structure is modeled by introducing an added mass matrix. Because the added mass matrix formed by the boundary element method is fully populated, it requires considerable computer memory when the wet modal analysis involves substantial wetted elements. Additionally, the dense added mass matrix will destroy the sparsity of the total mass matrix, resulting in a significant computational burden for solving the eigenvalue problem. Based on the cyclic periodic property of the fluid/structure system, it is proved that the added mass matrix of the vertical cyclic periodic tank also has a block-circulant property. Therefore, according to the group representation theory, the original eigenvalue problem of the wet modal analysis can be decoupled into a series of independent subproblems. Because the computational scale of the subproblems is much smaller than that of the original eigenvalue problem, the proposed method can significantly reduce the computational cost. Numerical examples show that the proposed method can solve the modal analysis of the cyclic periodic fluid/structure system with high accuracy and efficiency.