Numerical Study of Strouhal Instabilities in Two-Phase Flows


Predicting fuel spray interaction with large scale vortex structures still is a major challenge for state-of-the-art flow predictions. In order to elucidate the mechanisms involved, a fundamental study has been carried out in which the interaction of water droplets with Strouhal instabilities is investigated. A disperse two-phase flow around a cylinder is computed taking into account heat and mass transfer for both phases. Flow conditions are chosen such that large scale vortices are generated by Strouhal instabilities of the well known Karman vortex street. A homogeneous distribution of water droplets is injected into hot air at the up-stream region of the computational domain. The mixing process as well as the impact of the droplets on the Strouhal instabilities is analyzed in the downstream region with large scale vortex structures.