Applications of Computational Fluid Dynamics to Flow Ratings at Prototype Spillways and Weirs. II: Framework for Planning, Data Assessment, and Flow Rating

Abstract

Traditionally, flow-rating formulas for hydraulic structures are calibrated and validated with data comprising field measurements of discharge, water stages, and operational settings monitored in near real time. Lack of sufficient field measurements that include all flow types and cover the full operational ranges has been a major constraint in developing reliable flow ratings for prototype hydraulic structures. A companion paper introduced a plausible method that relies on computational fluid dynamics (CFD) simulations to generate accurate flow data that complements field measurements for flow rating analysis. In this paper, a general framework for applying CFD in flow rating is proposed, which includes planning of CFD simulations, assessing CFD flow data, and improving existing flow ratings using a hybrid data set of field-measured and CFD-simulated flows. Finally, two case studies of flow rating for spillways and weirs carried out to demonstrate the proposed framework are presented. Results show that the proposed framework offers a cost-effective approach that provides robust, comprehensive flow rating formulas that yield reliable flow estimates for the operation of hydraulic structures under multiple water-resource management constraints.