港池长周期波浪振荡模态研究

Long-period wave oscillation mode in harbor basin

在港口的建设中,往往修建防波堤对港域水体进行掩护。然而当外海波浪周期较长时,其掩护效果并不直观,长周期波浪侵入港域易引起港内水体发生强迫振动,港域波高幅值剧烈上升。文章结合某核电港物理模型试验,验证BW数值模型的合理性,二者结果吻合良好。利用白噪声探测了港域的固有频率,并利用微幅波研究了港池长周期波浪振荡的模态。具体结论如下:600~850 s、250~320 s、130~170 s为港池的固有频率,分别对应于港池的第一、第二、第三模态,港域的尺度分别与600~850 s波浪的1/4波长、250~320 s波浪的1/2波长、130~170 s波浪的3/4波长趋于一致。600~850 s对应的长周期波浪振荡幅度最大达到入射波浪振幅的6.6倍。

Breakwater is often built to protect the harbor basin,which won′t be well sheltered when the long-period waves propagate into the port,resulting in forced vibration of the water body.As a result,the wave height of the port area will rise sharply.The BW numerical model was verified by the wave filed simulation of a nuclear power port,which matched quite well with physical model test results.Based on it,the natural frequency of the port area was detected by incident white noise,and the long-period wave oscillation mode in the harbor basin was studied with the micro-amplitude waves.The following conclusions can be drawn:600-850 s,250-320 s,130-170 s are the natural frequencies of the harbor basin,corresponding to the first,second and third modes of the harbor basin respectively,when the scale of the port area coincides with 1/4 wavelength with 600-850 s period,1/2 wavelength with 600-850 s period,3/4 wavelength with 600-850 s period respectively;the long-period wave oscillation corresponding to 600-850 s is up to 6.6 times of the incident wave amplitude.