分层海洋中大振幅内孤立波频发，往往会对水下潜体等产生突发性载荷，甚至可能导致其失稳，引发“掉深”危险。为了研究大振幅内孤立波作用下固定潜体载荷特性，采用计算流体力学（CFD）的方法进行数值模拟，首先，针对大振幅内孤立波，提出了基于强非线性aHOU理论的内孤立波数值造波方法，采用速度入口造波的方式在计算域内生成内孤立波，建立了大振幅内孤立波与固定潜体相互作用数值计算模型。在此基础上，通过将建立的数值模型计算结果与实验数据对比，验证了数值模型的准确性和可靠性。最后，分别采用回归分析和控制变量法，探究波幅和潜深参数对内孤立波作用下潜体载荷特性的影响，获得了潜体在内孤立波波面上方、穿越波面和位于波面下方三种工况下潜体内孤立波载荷特性。研究表明，潜体内孤立波水平载荷正幅值与波幅存在能够定量表征的线性关系；内孤立波垂向力的作用时间与潜深相关，且在潜体穿越波面的工况下垂向力主要成分为压差力。本研究为深入理解内波作用下潜体“掉深”问题提供了理论基础。

In stratified oceans, large-amplitude internal solitary waves (ISWs) frequently occur, often accompanied by strong shear flows during their propagation. These waves can exert sudden loads on underwater bodies, potentially causing instability and leading to the danger of “falling deep” To investigate the load characteristics of fixed submerged bodies under the influence of these waves, computational fluid dynamics (CFD) methods were employed for numerical simulations. A numerical wave generation method based on the strongly nonlinear aHOU theory was developed specifically for large-amplitude ISWs, generating waves within the computational domain using a velocity inlet approach. This established a numerical model for the interaction between largeamplitude ISWs and fixed submerged bodies. The accuracy and reliability of the model were validated by comparing its results with experimental data. Additionally, regression analysis and control variable methods were utilized to explore the effects of wave amplitude and submergence depth on the load characteristics of the submerged body under ISWs. The study characterized the load properties of the submerged body in three scenarios: above the ISW surface, traversing the wave surface, and below the wave surface. Results indicate a quantifiable linear relationship between the positive amplitude of the horizontal load and wave amplitude, while the duration of the vertical force exerted by ISWs is related to submergence depth. Under the condition where the submerged body traverses the wave surface, the primary component of the vertical force is identified as the pressure differential force. This study provides a theoretical foundation for understanding the issue of “falling deep” in underwater bodies due to internal waves.