Hydraulic Flushing of Sediment in Reservoirs: Best Practices of Numerical Modeling

Abstract

This article provides a comprehensive review and best practices for numerically simulating hydraulic flushing for reservoir sediment management. Three sediment flushing types are discussed: drawdown flushing, pressure flushing, and turbidity current venting. The need for reservoir sediment management and the current practices are reviewed. Different hydraulic drawdown types are described in terms of the basic physical processes involved as well as the empirical/analytical assessment tools that may be used. The primary focus has been on the numerical modeling of various hydraulic flushing options. Three model categories are reviewed: one-dimensional (1D), two-dimensional (2D) depth-averaged or layer-averaged, and three-dimensional (3D) computational fluid dynamics (CFD) models. General guidelines are provided on how to select a proper model given the characteristics of the reservoir and the flushing method, as well as specific guidelines for modeling. Case studies are also presented to illustrate the guidelines.

Modelling of Granular Sediment Transport in Steady Flow Over a Mobile Sloped Bed

“…Various methods such as drawdown flushing, pressure flushing, and turbidity current venting are discussed. The need for sediment management in reservoirs to maintain their retention capacity and functionality is emphasized [1].…”

Environmental Hydraulics, Turbulence, and Sediment Transport, Second Edition

“…Using the MIKE-11 2D program, different erosion scenarios were simulated, with scenario of 75% O&M model identified as being the most suitable. Numerical simulation methods were applied for hydraulic flushing in reservoir sediment management, covering drawdown flushing, pressure flushing, and turbidity current venting [4]. The study discusses empirical/analytical methods and 1D to 3D computational fluid dynamic models.…”