When the underwater structure vibrates, the vibration changes the condition around the structure and the fluid field acts on the structure inversely. So a coupling system composed of the structure and the fluid field around the structure is formed.

• 结构在水下运行时会产生振动，这种振动会改变结构周围流场的运动，同时流场也会对结构产生作用，这样结构及其周围流场域就组成一个流固耦合系统。