Estimation of turbulent fragmenting forces in a high-pressure homogenizer from computational fluid dynamics

The aim of this study was to find models for turbulent fragmenting forces in the high-pressure homogeniser from data available in Computational Fluid Dynamics (CFD) simulations with Reynolds Averaged Navier Stokes (RANS) turbulence models. In addition to the more common RANS k–ε turbulence models, a Multi-scale k–ε model was tested since experimental investigations of the geometry imply large differences in behaviour between turbulent eddies of different length-scales.Empiric models for the driving hydrodynamic factors for turbulent fragmentation using the extra information given by multi-scale simulations were developed. These models are shown to give a more reasonable approximation of local fragmentation than models based on the previously used RANS k–ε models when comparing to hydrodynamic measurements in an experimental model.

► Fragmenting forces due to turbulence in a high-pressure homogeniser are modelled. ► Fragmenting forces are compared to experimental measurements. ► Traditional models are compared to ones using multiple length-scales. ► Estimates of fragmenting forces are improved by including two length-scales.