Development of model terms for fluid-particle interaction in turbulent flows via highly resolved numerical simulations
The numerical analysis of technically-relevant particulate flows in pulverized coal 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 coal 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 coal-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 coal 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 coal flows are developed by means of direct numerical simulations and are made available to the project partners simulating the whole coal-firing process.