> C. Ruyer-Quil
Liquid film in steam turbines
Amelie Simon (EDF)
Wetness in steam turbines induces losses and erosion. Drops are created due to the fast expansion of the steam (homogeneous nucleation) and the impurities in the steam (heterogeneous nucleation). The droplets grow and some among them settle on the blade leading to a thin liquid film. This film may then be atomized into coarse water drops which crash on the following blades.
The liquid film configuration is a thin film on a curved rotating surface, created by the drop deposit and under high steam friction. Moreover, due to interfacial instabilities, some drops are torn off from the film. The retained approach is an integral formulation (or Shallow Water equation with specific terms). The derivation of this equation requires some closure laws for the velocity at the free surface, for the convection contributions and for the Coriolis terms. Once chosen, a mathematical and mechanical analysis is performed (hyperbolicity, entropy, galilean and rotational invariance).