窄深矩形断面明渠流速分布的研究

建立了一个三维紊流数学模型，对实际灌区中的窄深矩形断面明渠水流的流速分布进行了数值模拟.计算结果与实测结果符合得较好，表明数学模型及参数是合理可靠的. 运用该模型，对2种底坡、2种糙率以及3种宽深比组合情况下的窄深矩形断面明渠水流的流速分布进行了数值模拟，得出了窄深矩形断面明渠垂线流速分布律和垂线平均流速横向分布律，并应用实测资料验证了上述流速分布律. 结果表明，在明渠底部内区流速分布能很好地符合对数分布律，但在明渠外区流速分布则符合抛物线分布，垂线平均流速沿横向的分布接近于幂函数分布，给出的断面流速分布经验公式具有很好的精度.

Velocity distribution in narrow and deep rectangular open channels

A 3-D turbulent numerical model was established, based on which numerical simulations of the flow in narrow and deep rectangular open channels of a real irrigation district were conducted. The computed results accord with the measured results, which show that the presented model is reasonable and reliable. Then the flow in narrow and deep rectangular open channels combined by two different base slopes, two different wall roughness and three different aspect ratios were numerically simulated. The laws of velocity vertical distribution and transverse distribution of mean vertical velocity were obtained and validated using the measured data The vertical velocity distribution in bottom inner region of open channel conforms to logarithmic distribution, but in outer region conforms to parabolic distribution. The transverse distribution of mean vertical velocity conforms to power function distribution. The presenteal empirical formulae of velocity distribution are accurate.