摘要: |
从风浪的能量平衡方程出发,引进若干风要素与波要素以及波要素之间的定性关系,经演算可导出海面阻力系数(CD)或是风速(U)和波龄(β)或是U和波高(H)的函数,然后沿用最小二乘法,终将得出4组12个回归方程。当β(或β)或Hs为某一给定值,惟有U为唯一参量时,所提各式均可简化为非线性方程: CD=a+b*U+c*U2;式中a,b和c为三个经验系数。就所检验的例子而言,本文的结果与实际的符合较前人的为好。 |
关键词: 海面阻力系数 波龄 波高 |
DOI: |
分类号: |
基金项目:国家自然科学基金资助项目,48770274号 |
|
INVESTIGATION ON MODELS OF BI-PARAMETERIC DRAG COEFFICIENTS OF SEA SURFACE |
Wang Binghang
|
Institute of Physical Oceanography, Ocean University of Qingdao,Qingdao 266003
|
Abstract: |
On the basic of the energy balance equation for wind waves, into the equation the relationships between wind parameters and wave parameters, and between wave parameters are introduced, and then it are derived that the drag coefficient of sea surface is a function of either the wind speed and wave height or the wind speed and wave age (β, orβ). The method of least squares is in turn used for determining expressions of the function, at last its general regressive equation is obtained as follows:
CDjk=ajk+bjk*Rk +cjk* Rk2 (26)
where j=l, 2, 3. 4; k=1, 2, 3: R1=U10/β*; β*=Cp/u*; R2=U10/β; β=C/U10; R3=Hs*U10; ajk, bjk, and cjk are empirical coefficients changing with atmospheric stability parameter, TV (=[(T10-Tn)/U102]×102); U10 and T10 are the wind speed (m/s) and air temperature (°C) at a height 10m above mean sea level, respectively; u* is the friction velocity (m/s) of air; Tw is the surface layer temperature (°C); Cp is the phase speed (m/s) of waves of the spectral peak. Physical quantities and numerical values related to equation (26) are listed in Table 1.
The wave age or the wave height being certain magnitude given, only the wind speed is left as a variable in the equation (26) there by reduced it to a nonlinear equation: CDjk=ajk'+bjk'*U10+cjk' *U102, where ajk', bjk' and cjk' are three empirical coefficients.
So far as the cases examined are concerned, the results obtained from the equation (26) have been compared with the practical observations, and better accordance has been achieved than those given by the forerunner’ s formulas. |
Key words: Drag coefficient of sea surface, Wave age, Wave height |