Shocks through a narrowing, accepted in JFM

What happens when a shock wave meets a short narrowing in a duct? Combining shock-tube experiments with validated large-eddy simulations, Raz Heppner, Hemanth Chandravamsi, Yoav Gichon, Steven Frankel and Omri Ram show that for abrupt constrictions the reflected shock depends almost only on how much of the duct is blocked, while for smoothly contoured ones it depends on the local slope as well, and that simple models predict both the reflected and the transmitted shock across the whole parameter space.

The paper has been accepted for publication in the Journal of Fluid Mechanics. A preprint is on arXiv.