河口底边界层湍流信号的噪声干扰实验

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。

Noise Experiments of Turbulence in Estuarine Bottom Boundary Layer

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 Gaussian 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 influence of white Gaussian noise on the energy spectrum is the largest, the influence of linear trend is not notable, 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 energy 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.