Author(s): Yongcan Chen; Dejun Zhu
Keywords: Trapezoidal cross-section open channel; Longitudinal dispersion coefficient; Velocity distribution; Information entropy
Abstract: Based on the maximum entropy principle, a velocity formula was derived to describe the variation of longitudinal velocity in both the vertical and transverse directions in a trapezoidal cross-section open channel. Influence of transverse and vertical velocity profiles on longitudinal dispersion was studied, and conclusions in fair agreement with the work of other researchers were drawn. Finally a formula for predicting the longitudinal dispersion coefficient in trapezoidal cross-section open channels was proposed. According to the formula, the longitudinal dispersion coefficient is determined by two parameters which reflect the inhomogeneity of velocity distribution and the influence of channel walls. The method on longitudinal dispersion coefficient prediction in this essay is not based on some special experimental results or field data. Because of the solid theoretical basis, this method can be used as an efficient tool for determining the longitudinal dispersion coefficient in any straight symmetrical trapezoidal cross-section open channels.