A comparative analysis of the hydrodynamic performance of a planing craft in the monomer-form state (MFS) and trimaran-form state (TFS) was performed, and the inhibition mechanism of twin side-hulls on porpoising instability was evaluated based on the numerical method. A series of drag tests were conducted on the monomer-form models with different longitudinal locations of the center of gravity (L_cg); the occurrence of porpoising and the influence of L_cg on porpoising by the model was discussed. Then, based on the Reynolds-averaged Navier–Stokes (RANS) solver and overset grid technology, numerical simulations of the model were performed, and using test data, the results were verified by incorporating the whisker spray equation of Savitsky. To determine how the porpoising is inhibited in the TFS, simulations for the craft in the MFS and TFS when porpoising were performed and the influence of side-hulls on sailing attitudes and hydrodynamic performance at different speeds were analyzed. Using the full factor design spatial sampling method, the influence of longitudinal and vertical side-hull placements on porpoising inhibition were deliberated, and the optimal side-hull location range is reported and verified on the scale of a real ship. The results indicate that the longitudinal side-hull location should be set in the ratio (a/L_m) range from 0.1 to 0.3, and vertically, the draft ratio (D_d/T_m) should be less than 0.442. Following these recommendations, porpoising instability can be inhibited, and lesser resistance can be achieved.

中文翻译：

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双舷侧船体对滑艇海豚失稳的抑制和流体力学分析

对滑行艇在单体状态（MFS）和三体船状态（TFS）下的水动力性能进行了比较分析，并基于数值方法评估了双舷壳对海豚失稳的抑制机理。对具有不同重心纵向位置（L _cg）的单体形式模型进行了一系列阻力测试；海豚的发生和L _cg的影响关于通过模型进行海豚化的讨论。然后，基于雷诺平均Navier-Stokes（RANS）求解器和过冲网格技术，对模型进行了数值模拟，并使用测试数据，通过结合了Savitsky的晶须喷雾方程来验证了结果。为了确定在TFS中如何抑制海豚着地，​​在进行海豚着地时对MFS和TFS中的航行器进行了仿真，并分析了船体在不同速度下对航行姿态和水动力性能的影响。使用全要素设计空间采样方法，研究了纵向和垂直舷侧布置对减震的影响，并在实际船的规模上报告并验证了最佳舷侧定位范围。a / L _m）的范围为0.1到0.3，垂直方向上的牵伸比（D _d / T _m）应小于0.442。遵循这些建议，可以抑制海豚的不稳定性，并获得较小的抵抗力。