A comparative analysis of particle- mixing plane interaction in multistage turbomachinery simulations

Rotor-stator interaction in turbomachinery is one of the most challenging fields in Computational Fluid Dynamics (CFD) and, in this regard, several studies can be found in the literature, concerning unsteady coupling of successive blade rows. The mixing plane for steady multistage calculations has been common for many years and, even though this technique is at present consolidated, the proper way of handling multiphase flows is not well defined. Currently, only a few particle-interface interaction studies are reported in the literature, hence strong limitations in particle-laden flow simulations in multistage turbomachinery arises. In order to fill up this lack, this work reports an analysis for particle-mixing plane interaction. Efforts have been done to supplement the Lagrangian tracking library of the open-source software foam-extend with an appropriate treatment of particles crossing mixing plane interfaces. The component analysed in this work is the first high-pressure stage of an Energy-Efficient Engine (EEE) axial turbine. The results of the study is compared to high-fidelity results obtained by a transient simulation based on a dynamic mesh approach. Three different techniques have been proposed and their performance has been assessed. One of the three methods has proved superior to the others in capturing the time-averaged effects of the unsteady flow on particle impacts and is therefore suitable when performing steady-state simulations.