Bubbly flow in an axisymmetric sudden expansion: Pressure drop, void fraction, wall shear stress, bubble velocities and sizes Original Research Article

In this work, a theoretical and experimental study of a bubbly flow in an axisymmetric sudden expansion is presented. A global model for the prediction of the singular pressure drop is derived and an experimental study relative to the dynamic parameters of the bubbly flow downstream of the singularity is given. The singular pressure drop has been obtained as a global formulation that integrates velocity form profiles, turbulence for every phase, and wall shear stress. In the experimental study, data concern pressure drop, wall shear stress, local and global void fraction, average and fluctuating bubble velocities and bubble sizes. These data constitute a quasi-complete experimental data bank with respect to Bel Fdhila and Simoninʹs recent works on the liquid phase of bubbly flow.