带坞舱船舶是进行水下装备布放回收的重要装备。然而，该类船舶在复杂海况下作业时，坞舱内易产生剧烈流体晃荡，影响作业安全。因此，准确预报坞舱内流体晃荡频率具有重要的意义。本研究对比分析了模型预报的固有频率与水动力学软件WAMIT计算得到的晃荡频率。研究表明解析模型的预测值与WAMIT计算值的相对误差在5%以内，且相对误差随共振阶数增大而减小，验证了解析模型的有效性。分析了各阶固有频率对应的坞舱内波高分布与坞舱纵向晃荡的模态。通过对比船体自由运动与固定两种情况下的坞舱内部自由面响应，研究了船体运动对坞舱内部流体固有频率的影响，发现随浪工况下船舶运动会使坞舱的纵向固有频率减小，在横浪工况下会使固有频率增大。此外，研究表明坞舱内部晃荡对船舶运动响应有着明显的影响。

Ships equipped with a dock are essential assets for the deployment and recovery of underwater equipment. However, when these ships operate in complex sea conditions, significant fluid sloshing can easily occur inside the dock, jeopardizing operational safety. Therefore, accurately predicting the fluid sloshing frequency inside the dock is of great importance. This study compares the natural frequencies predicted by an analytical model with those computed using the hydrodynamics software WAMIT. The results demonstrate that the relative errors between the analytical predictions and WAMIT simulations are within 5%, and these errors decrease as the resonant mode order increases, validating the reliability of the analytical model. The wave height distribution inside the dock and the longitudinal sloshing modes corresponding to each natural frequency are also analyzed. By comparing the dock's free-surface response under both freely floating and fixed hull conditions, the influence of hull motion on the natural frequencies of the internal fluid in a dock is investigated. It is found that hull motion in following seas reduces the longitudinal natural frequency of the dock, whereas in beam seas, it increases the natural frequency. Additionally, the study confirms that internal dock sloshing significantly affects the motion response of the ship.