Characteristics and Modeling of Intake Vortices

A review and analysis of forces, equations and data for free-surface intake vortices is presented. The effects of viscosity and surface tension are examined, in particular as they apply to Froude models. A comparison of vortex formation in a prototype and a 1:100 scale model is also presented. The analysis supports the use of Froude models, with certain provisos and limitations regarding in particular small-scale models of air entraining vortices, and indicates at the same time a need for additional data to quantify scale effects.