针对空气垫及来风对海洋结构物空中坠落入水过程产生重要影响的问题，在对结构物坠落机理进行分析的基础上，充分考虑结构物在空中坠落过程中所受到的空气阻尼及六自由度运动特点，结合流体三维瞬态 N-S 方程、湍流动力方程、能量方程和刚体 6自由度运动方程，建立了三维复杂结构物空中坠落砰击入水的气-固耦合过程数学模型．对结构物坠落砰击入水的数值模拟结果与物模试验结果的比较表明，该数学模型能有效模拟空气中的坠落砰击过程． 对不同高度以及来风时的坠落砰击过程的数值模拟表明:空气垫改变结构物砰击速度、压力分布;砰击会使空气垫温度上升;来风改变了结构物坠落姿态，使结构物在空中呈“之”字形摆动坠落并砰击水面．

As the air cushion and the wind both greatly affect the falling process of marine structures from the sky into the water，this paper proposes an air-solid coupled mathematical model to describe the falling slamming process of 3D complex structures． In the investigation，the falling mechanism of structures is analyzed，the air damping and the 6DOF (Degree of Freedom) motion characteristics are fully taken into consideration，and the three-dimension transient N-S equation，the turbulence dynamic equation，the energy equation and the rigid 6DOF kinematic equa-tion are comprehensively adopted． The proposed model is then applied to numerically simulate the falling slamming process of a structure from the air into the water，and the results are compared with those obtained by the physical model，finding that the proposed model is effective in simulating the falling slamming process． Moreover，from the simulated results obtained at different falling heights or in different wind blow environments，it is found that (1) the existence of air cushion changes not only the structure slamming speed but also the pressure distribution; (2) the slamming may result in a temperature rise of the air cushion; and (3) the wind blow changes the falling pose of structures and makes the structures fall from the air with a“zigzag”pose and then slam into the water．