Turbulence modelling of fluid-particle interaction

Abstract

The accurate prediction of turbulent fluid-particle behaviour has been a complex and elusive topic for researchers for several decades. The momentum and energy exchange between the fluid and particles, across the whole spectrum of spatial and temporal scales, leads to an abundance of rich physical behaviour which has ensured that significant advances in the area have proven challenging. This contribution seeks to shine a small ray of light on a vast and murky abyss in which the true nature of turbulent fluid-particle flows may allude us for some time still. This thesis presents a multi-scale continuum approach to modelling fluid-particle flows i.e. Eulerian-Eulerian (E-E). A fully-coupled Reynolds-Averaged Two-Fluid Model (RA-TFM) for turbulent fluid-particle flow, with particular emphasis on the near-wall region, is developed. The coupling is provided both mathematically i.e. the fluid-particle momentum and energy coupling across all spatial and temporal scales and numerically i.e. the RA-TFM governing equations are solved within a block-coupled matrix. The RA-TFM is derived, applied and validated against a plethora of benchmark experimental and Direct Numerical Simulation data in which a wide range of physical processes are present. Finally, the RA-TFM’s implementation within the open-source CFD toolbox OpenFOAM is detailed.