Air concentration measurements performed along the lower nappe of a bottom aerator through the impact and downstream flow regions permitted the calculation of air entrainment along the jet length. The air uptake was also measured in the air supply conduit. It was shown that integration of the concentration profiles along the jet overestimates the air uptake measured in the air supply conduit. Corrective procedures were developed by adapting the concept of entrained and entrapped air, in which the latter is re-circulated in the cavity, but both are measured by air concentration probes.
Bibliographical noteFunding Information:
The Authors thank Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (pr. 2201/06-2) and Fundação de Amparo à Pesquisa do Estado de São Paulo, for supporting this research.
- Air concentration measurements
- Air entrainment
- Air uptake
- Air-water flows
- Spillway aerators
- Void ratio