Inertially driven buckling and overturning of jets in a Hele-Shaw cell.
We study a fluid jet descending through stratified surroundings at low Reynolds number in Hele-Shaw flow. The jet buckles and overturns inside a conduit of entrained fluid which supports smooth or unstable traveling waves. A model of the recirculating flow within the conduit shows that buckling and waves arise from Kelvin-Helmholtz instabilities and quantitatively accounts for the main experimental observations. Beyond the onset of the instability, a damped, forced Burgers' equation obtained from corrections to Darcy's law for small Reynolds number governs the interface dynamics and supports singularities corresponding to the observed jet overturning and unstable waves.
Pesci
Adriana I
AI
Department of Physics and Program in Applied Mathematics, University of Arizona, Tucson, AZ 85721, USA.
Porter
Martin A
MA
Goldstein
Raymond E
RE