On the modelling of steady turbulent fountains
Résumé
The paper deals with steady-state turbulent fountains in a homogeneous surrounding. A set of mono-dimensional conservation equations is first derived from the Navier-Stokes equations. In contrast with equations used for plumes or rising fountains, these equations reveal additional terms in order to account for the effect of the (annular) down-flow on the fountain up-flow. Large-eddy simulations are then performed and used to determine, from radial profiles, the values of the constants (associated with these additional terms) to be fitted in the model. With these constants, analytical solutions of the model for steady-state fountain are proposed and compared with previous experiments.