摘要
为了探明卵石推移质输移脉动特性,对卵石推移质输沙率脉动试验野外实测资料进行了统计分析。实测资料结果表明,卵石推移质输沙率过程具有明显的随机性,其表征卵石推移质输沙脉动特性的特征值与采样历时密切相关。卵石推移质单宽输沙率的脉动标准差、离差系数、无量纲脉动强度以及无量纲极差值均随采样历时增加而减小。单宽输沙率的无量纲极差值最大为8.0左右,当采样历时t 600 s时,无量纲极差值Z 4.0,当采样历时t 2400 s时,无量纲极差值Z 2.0。单宽输沙率的离差系数最大为2.0左右,当采样历时t 1200 s时,离差系数Cv 1.0,当采样历时t 3000 s时,离差系数Cv 0.5。单宽输沙率的无量纲脉动强度最大为10.0左右,当采样历时t 1200 s时,无量纲脉动强度E′5.0,当采样历时t 3600 s时,无量纲脉动强度E′2.0。
By the analysis of the field data of gravel bedload rate, it is found that the gravel bedload rate has a distinct stochastic nature and turbulence intensity of bedload rate is closely related to the sampling duration. The deviation, diversity coefficient, dimensionless turbulence intensity and dimensionless ultimate difference of bedload rate per unit width, all decrease with the increase of sampling duration. The maximum value of dimensionless ultimate difference of bedload rate per unit width is about 8.0. As the sampling duration t≤ 600 s, the dimensionless ultimate difference Z ≤ 4. 0. As the sampling duration t≥ 2400 s, the dimensionless ultimate difference Z ≤ 2. 0. The deviation coefficient of bedload rate per unit width has a maximum value of 2.0. As the sampling duration t ≥ 1200 s, the deviation coefficient Cv ≤1.0. As the sampling duration t ≥ 3000 s, the deviation coefficient Cv ≤ 0. 5. The dimensionless turbulence intensity of bedload rate per unit width has a maximum value of 10.0. As the sampling duration t ≥ 1200 s, the dimensionless turbulence intensity E＇ ≤ 5.0. As the sampling duration t ≥ 3600 s, the dimensionless turbulence intensity E＇ ≤ 2. 0.
出处
《四川大学学报（工程科学版）》
EI
CAS
CSCD
北大核心
2006年第6期43-46,共4页
Journal of Sichuan University (Engineering Science Edition)
基金
973资助项目(2003CB415202)
关键词
脉动特性
卵石推移质
采样历时
fluctuation nature
gravel bedload
sampling duration
