Author(s): Troy C. Lyons

Linked Author(s): Troy Lyons

Keywords: Drop shaft; air entrainment; vortex drop structure; plunge drop structure; plunging jet

Abstract: Plunge-flow drop shafts are generally considered to be less efficient and prone to entrap higher amounts of air compared to vortex-type drop shafts. To investigate the perceived differences in air demand, the current work evaluates air demand in a vortex-type drop shaft using a reduced-scale physical model and compares the results to available data from other model studies that employ both plunge- and vortex-flow drop shafts. The analysis reveals that both types of drop shafts entrain large amounts of air and that there are additional factors beyond shaft type that influence the amount of air entrainment. However, the evidence clearly showed higher air entrainment rates in plunge-type drop shafts when compared to vortex-type drop shafts. In general, plunge-type shafts entrain about ten to fifteen times more air than vortex-type shafts when comparing equivalent shaft heights and water flow rates.

DOI: https://doi.org/10.3929/ethz-b-000675921

Year: 2024