波浪数学模型中谱分割功能的应用

Implementation of spectral partition in wave models

海洋风浪的数值模拟常以全谱有效波高作为模拟结果,并在验证时将它与实测风浪记录相对比.实际上,全谱中既包含了当地风浪部分,也包括了外海传入的涌浪部分,其有效波高在物理意义上并不等价于风浪波高.采用海浪模型WAVEWATCH-III和MIKE21-SW进行西北太平洋海域的风浪后报,并应用模型的谱分割功能,可对完整的波谱进行分割,分离出风浪和涌浪部分.数值计算结果对比证实:利用该功能得到的分离波高不仅能提高风浪模拟的精度,也使波能状态信息更加完善.另外,对比发现WAVEWATCH-III相对于MIKE21-SW表现出更好的效果.建议在模拟有涌浪成分的风成浪时应采用谱分割功能.

In ocean wave simulation,significant wave heights of the total spectrum are usually considered as the final results and are compared with observed wind waves during numerical wave model calibration.However,a real spectrum usually includes both the local wind waves and the swells coming from deep sea;therefore,the significant height is not equal to wind wave height in physical meaning.The wave models WAVEWATCH-Ⅲ and MIKE21-SW are applied to hindcast the ocean wave field of the Northwest Pacific.Meanwhile,the numerical approach of spectral partition can separate swells and wind waves from the total spectrum.Comparisons between calculated wave heights and measurements show that the function of spectral partition can increase the accuracy of simulation and improve the integrity of information of the wave energy status.In addition,WAVEWATCH-III gives a better partition result than MIKE21-SW.Therefore,it is reasonable to apply spectral partition in numerical simulations relating to wind-generated wave that contains swell.