Entrainment Descriptions for Mathematical Modeling of Pumped-Storage Inflows in Reservoirs

摘要

During hydropower generation and pumpback operations of pumped-storage projects, inflows are introduced into the reservoir system. These jetlike inflows often cause considerable entrainment of ambient water. The entrainment process can have a strong influence on the verical distribution of reservoir water quality when pumped-storage inflow jets are discharged into a stratified reservoir. The objective of this study was to develop algorithms to describe the pumped-storage inflow entrainment process for use in reservoir water quality models. Pumped-storage inflow jets fall into two classes: strongly or weakly buoyant. The former class has been fairly extensively studied, and well-established mathematical models exist to predict their behavior. For this case, incorporation into a reservoir thermal model simply required adaptation of existing code. For the latter case, however, that of weakly buoyant jets,, it was found that little information existed of either a theoretical or experimental nature. For that reason, an extensive series of experiments of a fundamental nature were performed on weakly buoyant jets into arbitrary stratification. The results were then reduced to a form suitable for inclusion into reservoir water quality simulation models. The developed algorithms were incorporated into an existing reservoir thermal simulation code, and a test application was made for Carters Lake, a Corps of Engineers pumped-storage project in Georgia. Keywords: Entrainment; Inflow jets; Mathematical models; Pumped-storage reservoirs.