(577a) Quantitative Prediction of Industrial Turbulent Processes in Stirred Tank Reactors- Invited Presentation in Turbulent and Reactive Flows

CFD has been used to model flows in stirred tanks for many years. Different levels of success have been achieved for this purpose. For example, it has been widely accepted that CFD can predict mean velocity field of a turbulent flow in a stirred tank with reasonable accuracy using RANS model. More recent publications have shown that LES turbulence models provide more accurate prediction of time dependent turbulent flows. Although, good prediction of flow field is important, we should keep in mind that the ultimate goal for an industrial application is to predict process results, such as mixing, reaction, mass transfer, etc. For process industry, two basic measures for the performance of a stirred tank reactor are mixing time and mixing quality. Both require quantitative accuracy from CFD solutions. Quantitative predictions for reactive systems and multiphase systems are more challenging. Are today's CFD codes and computers ready to satisfy such quantitative requirements for industrial applications? What are preventing us from obtaining accurate mixing results? In this talk, we will first reaffirm what process industry is looking for from CFD solutions. Then we will discuss some key challenges/obstacles in our way to achieve such solutions.