(192a) On the Trailing Vortices behind Impeller Blades in Stirred Vessels
AIChE Annual Meeting
2023
2023 AIChE Annual Meeting
North American Mixing Forum
Advances in Computational Analyses of Mixing Processes: Fundamentals
Monday, November 6, 2023 - 12:30pm to 1:00pm
Over the years, both experimental and computational techniques have developed tremendously. We now have Stereo Particle Tracking Velocity with 2 or 4 high-speed cameras on the experimental side alongside Large Eddy Simulations (based on the lattice Boltzmann technique) and Detached Eddy Simulations, often supplemented with Lagrangian particle tracking routines, which are increasingly replacing the common RANS-based simulation techniques (on the basis of k-epsilon modelling). Of course, this leaves the option open that old experimental as well as old calculated data get outdated. However, what both the novel experimental and simulation techniques have in common is that they heavily rely on numerical techniques including data processing routines which are outside the scope of most users.
In this review, older and recent data about the flow over impeller blades from both experiments and simulations are evaluated and mutually assessed. The focus is on the trailing vortices behind impeller blades of both Rushton and Pitched-Blade impellers. The intriguing question is addressed whether or not, in these trailing vortices or otherwise, velocity vector magnitudes in excess of the impeller tip speed are feasible.