Transfer Function Formulation of Saint-Venant's Equations for Modeling Drainage Channel Flow: An Experimental Evaluation

Abstract

Space constraints in developed urban cities necessitate utilizing existing capacity of the drainage system for actively controlling and optimizing the flow during a flood event. This is mainly achieved by the use of non-structural control measures (in the form of suitable controllers and control strategies) for controlling existing structures such as gates in the drainage system. However, the timely opening and closing of gates is fully governed by the rapid feedback and real time control of these structures. Hence, for an extreme rainfall event and flooding, it is necessary to rapidly model the peak flow and time to peak in the drainage system, the results of which can be used for the timely operation of the control structures. Owing to the fact that the conventional modeling methods are quite time consuming and cumbersome, a simplified approach based on transfer function formulation of Saint-Venant's equations have been proposed in this study. The simplified approach has been validated with the help of carefully planned laboratory experiments in which a test setup consisting of a model drainage channel with upstream and downstream gates have been developed. This laboratory model was used to simulate different flow conditions by the appropriate opening and closing of upstream and downstream gates. It was noted that the results obtained using the simplified approach matches well with the experimentally observed trends. This demonstrates the robustness of the new simplified approach for modeling flow conditions in drainage system.