Large Eddy Simulation of turbulent flowand heat transfer in a Kenics static mixer

CFD modelling of momentum and heat transfer using the Large Eddy Simulation (LES) approach hasbeen presented for a Kenics static mixer. The simulations were performed with the commercial codeANSYS Fluent 15 for turbulent flow of three values of Reynoldsnumber,Re=5 000, 10 000 and18 000. The numerical modelling began in the RANS model, where standardk−εturbulence modeland wall functions were used. Then the LES iterations started from the initial velocity and temperaturefields obtained in RANS. In LES, the Smagorinsky–Lilly modelwas used for the sub-grid scalefluctuations along with wall functions for prediction of flowand heat transfer in the near-wall region.The performed numerical study in a Kenics static mixer resulted in highly fluctuating fields of bothvelocity and temperature. Simulation results were presented and analysed in the form of velocity andtemperature contours. In addition, the surface-averaged heat transfer coefficient values for the wholeinsert length were computed and compared with the literature experimental data. Good compliance ofthe LES simulation results with the experimental correlation was obtained.