(249d) Large Eddy Simulation of an Inline Rotor-Stator Mixer and Comparison with High Resolution Piv Measurements

Rotor-Stator mixers are high-shear devices used for both batch and continuous multiphase processes that require liquid-liquid emulsification, wet grinding, and other high-intensity applications. The fundamental fluid mechanics governing performance of a prototype inline rotor-stator mixer operating in the turbulent regime has been studied via Particle Image Velocimetry, and the ability of RANS CFD simulations to accurately predict the mean velocity field and flow structures has been verified via detailed comparison with data, as previously reported. More recently, we have used a finite element CFD code to perform a large eddy simulation of the prototype rotor-stator mixer in an effort to capture more detailed features of the flow. We will report on the ability of the LES simulation to predict the mean field, as was previously done for RANS simulations. In addition, the ability of the LES simulation to elucidate important properties of the flow that were not previously available or accurately predicted by RANS simulations will be evaluated and reported on. In order to accomplish a meaningful comparison between the LES simulation and experimental data, we have refined our analysis of PIV data in a manner that highlights the transient, fluctuating properties of the flow. Properties of the simulation that will be presented and compared with data include, among other things, the instantaneous resolved energy dissipation. Perhaps more importantly, however, we will compare the nature of fluctuations which give rise to the observed patterns of mean flow structures, turbulent kinetic energy, its dissipation, and rate of production between the simulation and experimental data.