Reservoir Flow Sensitivity to Inflow and Ambient Parameters

Abstract

The effects of inflow boundary conditions, ambient stratification, and geometry on the behavior of a density-induced current in a stratified reservoir are quantified through numerical experiments with a validated two-dimensional (2D) simulation model. Dimensionless parameters characterizing inflow, ambient water, and geometry are defined and their practical ranges are selected. Variables describing reservoir flow mixing and transport in various flow regimes are determined from the simulated 2D distributions of velocities, concentration, temperature, and density. Present simulations are compared with previous field and laboratory studies of plunge depth. Model results are analyzed to evaluate reservoir flow sensitivity to changes in the parameters, using an influence coefficient method. The sensitivity analysis presents quantitative evidence that reservoir flow is more sensitive to Froude and Reynolds numbers than to other parameters (stratification number, aspect ratio, and side expansion). A critical value for each parameter is identified, which divides significant and insignificant effects on flow and dilution. The results can assist in field measurement, contamination monitoring and control, and reservoir management for the improvement of water quality and protection of the aquatic environment.