为研究三参量风浪频谱随风浪的成长关系,从而直观地描述风浪频谱成长过程中的超射现象,并证明三参量谱谱型的合理性。基于已得到的谱参量随风区的变化关系,对三参量风浪频谱以及风浪频谱成长过程中存在的t·超射’’现象作深入的研究,得到三参量风浪频谱随风区的成长关系:S(^-ω,^-m0,^-ω0,B)=^-m0(^-x)/^-ω0(^-x)B(^-x)[^-ω/^-ω0(^-x)]^-p(^-x) exp[-p(^-x)/q(^-x){[^-ω/^-ω0(^-x)]^-q(^-x)-1}]在此基础上,得到无因次风区:300、500、2000、5500、10000、15000下,风浪频谱的谱线,从而直观地描述了风浪频谱成长过程中的“超射’’现象,并认为在风浪频谱的成长过程中确实存在着“超射”现象,但是该现象并不如Hasselmann等提出的理论中阐述的那样存在于风浪频谱成长的全过程,而是仅存在于风浪频谱成长的初期。随着风浪的不断成长,“超射”现象逐渐减弱,直到风浪接近充分成长,“超射”现象也随之逐渐消失。经过不同风区下实测数据的检验,证明S(ω,^-m0,^-ω0,B)、S(ω,^-H,^-T,B)、S(ω,^-H,^-T,δ)以及S(ω,^-H,^-T,β)四种形式的三参量风浪频谱谱型是合理的,同时也进一步证明了谱的零阶矩、谱的峰频率、谱宽度、波高、周期、波陡和波龄随风区变化关系的正确性。
Growth relationship between wind wave spectra of three parameters and wind wave is studied, with which overshot that appears during the wind wave spectra development can be described more clearly. The growth relationship between spectrum parameter and fetch were studied, from which three parameters and overshot phenomenon that appears during wind wave spectra developing were tested, and an equation describing the growth of three-parameter spectra with wind wave was obtained:S(^-ω,^-m0,^-ω0,B)=^-m0(^-x)/^-ω0(^-x)B(^-x)[^-ω/^-ω0(^-x)]^-p(^-x) exp[-p(^-x)/q(^-x){[^-ω/^-ω0(^-x)]^-q(^-x)-1}] With the equation, the spectra of wind waves were obtained at zero-dimensional fetches of 300, 500, 2000, 5500, 10000, and 15000, and the overshot was described more clearly. However, the overshot does not exist in the whole process of wind wave spectrum development as stated previously by Hasselmann, but in the early stage of the development only, extenuates with wave growth and then disappears when the wave fully grows. Tested against observational data, four different three-parameter wind wave spectraS(ω,^-m0,^-ω0,B)、S(ω,^-H,^-T,B)、S(ω,^-H,^-T,δ)、S(ω,^-H,^-T,β) were proved reasonable. Mean-while, the growth relationships between fetch and spectrum variance, peak frequency, spectrum width, wave height, wave period, wave steepness, and wave age were also validated.