(147f) Chasing Flow Instabilities with Paul Steen

Paul Steen was my uncle, the academic brother of my thesis advisor E. B. Dussan V, and son of my academic grandfather Steve Davis. I worked closely with Paul since the early 2000’s while at Eastman Kodak Company in Rochester (I subsequently moved to RIT in 2007), served on four of his student’s thesis committees, and wrote a few papers with him and his students on planar flow casting of metals. Through its geometrical similarities to roll-to-roll slot coating to create long planar sheets of liquid films, I was able to work with Paul and his students to examine operability limits and instabilities in planar-flow casting. In this presentation, I will give a high level overview of some of the work I was privileged to be a part of, and also provide some memories in working with Paul and his students. I will also discuss some related recent work (with Nate Barlow from RIT) that shows how the classification of flows as neutrally stable, via dispersion relations derived from exponential modes, can be flawed. Some of Paul’s work with students involved the sustained oscillations of confined inviscid liquid globes which he applied effectively to planar flow casting, adeptly extracting key scales and quantitative relationships both theoretically and experimentally. In this context, our recent work on neutral stability of waves may be viewed as related work, and is dedicated to his memory.