Modelling of the tributary momentum contribution to predict confluence head losses

TLDR: In this paper, the authors proposed a new model to determine the head losses at confluences in one-dimensional models of open channel networks, making use of a momentum conservation approach.

Abstract: This paper proposes a new model to determine the head losses at confluences in one-dimensional models of open channel networks, making use of a momentum conservation approach Momentum conservation has been applied in several theoretical models for confluence head losses, giving satisfactory results in general However, for larger confluence angles between the main channel and the incoming tributary, the model accuracy diminished Many authors identified that a correct estimation of the tributary momentum contribution is a prerequisite for accurate results This work reports on the development and application of a theoretical model for the tributary momentum contribution, based on similarities with the flow upstream of a circular bend in a straight open channel It describes the two-dimensional depth-averaged flow features in the tributary under the assumption of a 90° angle confluence in which all channels have equal widths, in order to obtain the resulting momentum contribution The proposed mod