Laboratory measurements and numerical simulations of overtopping nappe impingement jets

© 2015 Taylor & Francis Group, London.Rectangular jets constitute one of the energy dissipation methods in the overtopping of dams. The high turbulence and aeration phenomena that appear in falling jets and dissipation basins make it difficult to carry out studies based only on classical methodologies. There are studies modeling spillways with Computational Fluid Dynamics (CFD) which produces accurate results. However, the study of overflow nappe impingement jets has not been sufficiently examined. Simulations of free air-water overflow weirs are scarce, and require small mesh sizes and a high computational effort. This work seeks to address such simulation. Results obtained with ANSYS CFX are compared with laboratory measurements and empirical formulae. Good agreement is obtained with experimental and theoretical data. Knowing the parameters analyzed, designers will be able to estimate the scour effects and the stability of the dam with a higher certainty.