河口底边界层湍流信号的噪声干扰实验

Noise Experiments of Turbulence in Estuarine Bottom Boundary Layer

基于河口底边界层实测湍流资料,选取了高斯白噪声、线性趋势项和周期项3种不同类型的噪声,讨论了各种噪声对湍流信号的影响。结果表明:①3种类型的噪声对湍流信号的概率分布影响不大,但对能谱曲线有较显著的影响。其中,白噪声对能谱值的影响最大,趋势项对能谱值的影响不明显,周期项仅对特定频率的能谱值有影响。②对于湍流强度、脉动能量和湍动能耗散率这3个湍流特征参数,白噪声和周期项对3种参数均有影响,而趋势项仅对湍强和脉动能量有影响。当湍流信号叠加上3种类型的噪声后,会使湍流特征参数有增大的趋势。

In this paper , the effect of various noises on the turbulence was discussed based on the field observation data in estuarine bottom boundary layer , and choosing three kinds of noise , the white Gaussi-an noise , the linear trend , and the periodic signal .The following results have been obtained：（ 1 ） The energy spectrum of the turbulence is more obviously affected than the probability distribution .The influ-ence of white Gaussian noise on the energy spectrum is the largest , the influence of linear trend is not no-table, and the periodic signal only makes effects on specific frequency .（2） White Gaussian noise and periodic signal both have influence on these three turbulent parameters：turbulent intensity , turbulent en-ergy and turbulent energy dissipation rate , but the linear trend only has influence on turbulent intensity and turbulent energy .Adding noises to the turbulence will make the turbulent parameters increase .