A Validation of the Junction Riemann Problem in Networks of Channels Under Transitory Flow Conditions

Transitory states and supercritical regimes in channel junctions have been challenging to model using 1D models, and it has been common to resort to 2D models to locally solve networks of channels. In this paper, we present a methodology based on the Junction Riemann Problem that manages to include supercritical solutions by making use of suitable limiting coefficients. The method is compared against a pure 2D model in a series of test cases with challenging geometries that include transitory flow conditions. The results show that the method hereby presented is robust across all regimes and is able to capture the main features of wave propagation along a network of channels.