Abstract

ARAGON-HERNANDEZ, José Luis  and  BLADE, Ernest. Numerical modeling of mixed flow in closed conduits with finite volume schemes. Tecnol. cienc. agua [online]. 2017, vol.8, n.3, pp.127-142. ISSN 2007-2422.  https://doi.org/10.24850/j-tyca-2017-03-08.

This paper presents a numerical model for simulating mixed flow (free surface and pressurized flow) in closed conduits through the one-dimensional Saint Venant equations for free surface flow and the method Preissmann slot to consider the pressurized flow. To solve the equations the finite volume method with a high resolution scheme is used. The used scheme is the Godunov method with the Roe solver Riemann with precision of first order, plus a second-order corrections to obtain the high resolution WAF-TVD scheme. The mixed flow is a common phenomenon in storm sewers, tunnels, pipes of hydroelectric installations, filling/draining pipes, storage collectors, etc. The pressurized flow in close conduits can be generated from downstream end, upstream end and both ends simultaneously; the first one is the most common, therefore will be evaluated in this study. To demonstrate the performance of the model, the numerical model is applied to a reference test and a two laboratory tests existing in the technical literature. The results show that the numerical model is able to reproduce the experiments with good accuracy. This shows that the model is suitable to simulate subcritical, supercritical and transcritical (from subcritical to supercritical and from supercritical to subcritical flow) free surface and mixed flow.

Keywords : Free surface flow; pressurized flow; mixed flow; Preissmann slot; finite volumes and storm sewers.