Hydrodynamics in Two-Phase Turbulent Boundary Layers

The corrections for log law must be taken into account the presence of bubbles in the two phase turbulent boundary layer. In the present study, a logarithmic law for the wall based on the supposition of additional turbulent viscosity associated with bubble wakes in the boundary layer was proposed for bubbly flows. An empirical constant accounting both for shear induced turbulence interaction and for non-linearity of bubble was determined for the new wall law, this constant was deduced from experimental measurements. In the case of a turbulent boundary layer with millimetric bubbles developing on a vertical flat plate, the wall friction prediction achieved with the wall law was compared to the experiences. We obtained a good concordance between experimental and numerical result. This significant agreement for wall friction prediction was particularly important for the low void fraction when bubble induced turbulence have a considerable role.

Keywords:

Bubbly two phase flows , Wall law , Turbulent boundary layer