-Theoretical form of equilibrium range is given on the basis of the wind wave frequency spectra proposed by Wenel al. (1988a,b,c, 1989a,b). The effects of peakness factor and water depth are discussed. In the case of ...-Theoretical form of equilibrium range is given on the basis of the wind wave frequency spectra proposed by Wenel al. (1988a,b,c, 1989a,b). The effects of peakness factor and water depth are discussed. In the case of deep water the e-quilibrium range is reduced to the form first proposed by Toba (1973) and the coefficient of the formula is shown to be the function of nondimensional fetch or peak frequency. Results of the present paper have been verified through field data.展开更多
It is generally believed that the equilibrium range of wind wave spectrum is in the form of the-4 rather than-5 power law.However,in the widely applied P-M spectrum the equilibrium range is given in the form of-5 powe...It is generally believed that the equilibrium range of wind wave spectrum is in the form of the-4 rather than-5 power law.However,in the widely applied P-M spectrum the equilibrium range is given in the form of-5 power law.In the present paper,a spectrum for full development of wind waves is proposed using the form of the Neumann spectrum,but adopting the-4 power law for the equilibrium range.The proposed spectrum has been verified with NDBC buoy data and could be a substitute for the P-M spectrum.展开更多
This paper presents a general theory for the apparent energy distribution of sea waves. Using the joint distribution of wave periods and heights proposed earlier by the second author, the authors define the generalize...This paper presents a general theory for the apparent energy distribution of sea waves. Using the joint distribution of wave periods and heights proposed earlier by the second author, the authors define the generalized apparnt energy distribution and derive the analytical form of the so called generalized outer frequency spectrum or nth-order frequency spectrum. Some possible relationships between it and the Fourier frequency spectrum are discussed. It is shown that the widely used Bretschneider spectrum can be easily obtained from the above definition and that generalized outer frequency spectrum has equilibrium range with exponent -(n+3) whose upper limit is -3.展开更多
Laboratory experiments and field observations show that the equilibrium range of wind wave spectra presents a – 4 power law when it is scaled properly. This feature has been attributed to energy balance in spectral s...Laboratory experiments and field observations show that the equilibrium range of wind wave spectra presents a – 4 power law when it is scaled properly. This feature has been attributed to energy balance in spectral space by many researchers. In this paper we point out that white noise on an oscillation system can also lead to a similar inverse power law in the corresponding displacement spectrum, implying that the – 4 power law for the equilibrium range of wind wave spectra may probably only reflect the randomicity of the wind waves rather than any other dynamical processes in physical space. This explanation may shed light on the mechanism of other physical processes with spectra also showing an inverse power law, such as isotropic turbulence, internal waves, etc.展开更多
文摘-Theoretical form of equilibrium range is given on the basis of the wind wave frequency spectra proposed by Wenel al. (1988a,b,c, 1989a,b). The effects of peakness factor and water depth are discussed. In the case of deep water the e-quilibrium range is reduced to the form first proposed by Toba (1973) and the coefficient of the formula is shown to be the function of nondimensional fetch or peak frequency. Results of the present paper have been verified through field data.
基金the National Natural Science Foundation of China (40830959)the Ministry of Science and Technology of China (2011BAC03B01)
文摘It is generally believed that the equilibrium range of wind wave spectrum is in the form of the-4 rather than-5 power law.However,in the widely applied P-M spectrum the equilibrium range is given in the form of-5 power law.In the present paper,a spectrum for full development of wind waves is proposed using the form of the Neumann spectrum,but adopting the-4 power law for the equilibrium range.The proposed spectrum has been verified with NDBC buoy data and could be a substitute for the P-M spectrum.
文摘This paper presents a general theory for the apparent energy distribution of sea waves. Using the joint distribution of wave periods and heights proposed earlier by the second author, the authors define the generalized apparnt energy distribution and derive the analytical form of the so called generalized outer frequency spectrum or nth-order frequency spectrum. Some possible relationships between it and the Fourier frequency spectrum are discussed. It is shown that the widely used Bretschneider spectrum can be easily obtained from the above definition and that generalized outer frequency spectrum has equilibrium range with exponent -(n+3) whose upper limit is -3.
基金This study was financially supported by the National Natural Science Foundation of China （Grant No. 40406008）the Foundation for 0pen Projects of the Key Lab of Physical 0ceanography, the Ministry of Education, China （Grant No. 200309）.
文摘Laboratory experiments and field observations show that the equilibrium range of wind wave spectra presents a – 4 power law when it is scaled properly. This feature has been attributed to energy balance in spectral space by many researchers. In this paper we point out that white noise on an oscillation system can also lead to a similar inverse power law in the corresponding displacement spectrum, implying that the – 4 power law for the equilibrium range of wind wave spectra may probably only reflect the randomicity of the wind waves rather than any other dynamical processes in physical space. This explanation may shed light on the mechanism of other physical processes with spectra also showing an inverse power law, such as isotropic turbulence, internal waves, etc.
