# gst: two instabilities in one liquid sheet.

<< ️Two cylindrical liquid jets (dia = 1 mm) of a glycerol-water mixture (80/20) impinge at 90º to one another, creating a thin liquid sheet bordered by a thick rim. Classical fish-bone shapes (sheet-thread-droplet) are formed where the rim instability is driven by Rayleigh-Plateau type mechanisms. >>

<< ️Here (AA) also see fish-bone shapes occurring for similar reasons. However, the waves on the sheet are formed by small imbalances between the two jet velocities (natural pipe driven oscillation), rather than the traditional Kelvin-Helmholtz instability. (They) stroboscopic photograph of the sheet reveals that both of these instabilities can coexist within a narrow range of operating conditions. >>

<< ️The breakup of the liquid sheet (lower down) is caused by the combined instability of spatially growing waves. The liquid sheet breaks down mainly through the growth of bounded waves. These waves eventually break, forming long threads at the bottom of the sheet, which further disintegrate into droplets due to the Rayleigh-Plateau instability of threads. >>

Sandip Dighe, Hrishikesh Gadgil, Tadd Truscott. Two instabilities in one liquid sheet. Phys. Rev. Fluids 10, 110501. Nov 20, 2025

https://journals.aps.org/prfluids/abstract/10.1103/nvkn-hk4g

77th Annual Meeting of the APS Division of Fluid Dynamics (Nov 24 — 26, 2024). P2692828: Two instabilities in one liquid. 

https://gfm.aps.org/meetings/dfd-2024/673f8914d88f37002bbe76d8

Also: waves, instability, transitions, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, waves, instability, transitions.