Author(s): Donatella Termini; Massimo Greco
Keywords: Flow resistance; shear velocity; rough bed; numerical simulation
Abstract: Accurate estimate of flow-velocity profile is of crucial importance both for scientific purposes and for solving numerous engineering problems that include, among others, sediment transport, contaminant transport, flow resistance evaluation. This paper presents a new empirical equation to represent the vertical velocity profile. The proposed equation is essentially a modified form of the well-known logarithm law of the wall and contains three parameters having a clear physical meaning. The applicability of the equation and its accuracy assessment for different hydraulic conditions, including non-uniform conditions, is verified by using experimental data obtained by different sources. The values of the mean square errors determined by the best-fitting of the law to the selected experimental data, are compared with those obtained by applying other equations proposed in literature. The comparison highlights that the proposed law allows the reproduction of all the hydraulic conditions examined maintaining an acceptable value of the mean square error.