B2

Development of modelling approaches for fluid-particle interactions in turbulent flow by direct particle-fluid simulations

The numerical analysis of technically-relevant particulate flows in pulverized solid fuel burners is challenging due to its multi-scale character.

For the simulation of the plain turbulent flow field models are available based on either temporally averaged or spatially filtered quantities. Upon addition of pulverized solid fuel particles the influence of the non-resolved scales on the particles additionally has to be modeled as well as the impact of the particles on the flow field. The simulation of solid fuel-burners therefore requires validated models which are – especially in the case of larger particles and a significant conjugate heat transfer with the carrier phase – not or only partially available.

In this project the required model terms are determined via highly-resolved simulations. The flow field about individual solid fuel particles is fully resolved such that the particle dynamics and the heat transfer of the Oxy-Fuel atmosphere in turbulent free shear layers can accurately be determined. The knowledge of the varying particle temperatures is essential for the prediction of the ignition process in particle-laden flows. Models for the description of the particle dynamics and their heat-up process in pulverized solid fuel flows are developed by means of direct numerical simulations and are made available to the project partners simulating the whole solid fuel-firing process.