Advanced CFD simualtion for mixing processes using LES turbulence model

 
CFD (computational fluid dynamics) is becoming standard in the chemical industry for scale-up, process design and optimization. The increase of CPU speeds and the novel use of graphic cards for scientific computations, makes now feasible the implementation of more advanced and also computing-intensive turbulence models such as Large Eddy Simulation (LES), which offers an unparalleled high resolution of turbulent structures. CFD simulations using a LES turbulence model are capable of predicting local energy dissipation and turbulence intensities with a much higher degree of accuracy than conventional CFD techniques such as RANS (Reynolds-Averaged Navier Stokes). The implications for the chemical industry are significant when analyzing turbulent mixing for homogenization and dispersion processes. In stirred tank reactors containing shear-sensitive compounds, for example, the only method to quantify shear-forces when designing mixing equipment was to calculate the averaged velocity gradient. Now, with LES-CFD simulations shear forces can be locally quantified and analyzed with high accuracy.