Embracing and Controlling Chaos in Fluidization – in Honor of Stuart Daw

Thirty years ago, Stuart Daw’s pioneering work, recognizing fluidized beds as deterministic chaotic systems, profoundly changed the way we consider their complex hydrodynamics. The ensuing work at ORNL and Delft allowed for refreshing approaches to embrace this complexity in fluidization, building on chaotic attractor properties, and use them to characterize fluidized beds, facilitate scale-up, provide an early warning of agglomeration, and, ultimately, open up avenues to control their behavior. I will briefly review this path, as a renewed look at holistic, “complex systems” behavior is timely, to complement bottom-up multiscale approaches, leveraging superior computational resources and algorithms, and informed by ever improving characterization methods. I will illustrate how fluidized beds could be intensified and structured, by controlling their chaotic hydrodynamics.