MSC Seminar. 27/01/2025. Philippe Claudin (PMMH, ESPCI): “Turbulent flows over wavy beds: Hanratty’s anomaly and its consequences”

The description of the flow fields in response to a bed perturbation is a fundamental subject that is generic for many geomorphological problems. We will address this question, and in particular the existence of an anomalous regime, which was experimentally evidenced by Hanratty and coworkers in the 70-80s, for intermediate values of the Reynolds number based on the wavelength of the bed perturbation. We will also discuss the consequences of this anomaly for the formation sedimentary/melting/sublimating patterns, e.g. sublimation scallops in ice caves (see photo).