Shear stripping atomization
Phys. Rev. Fluids 10, 103602 – Published 21 October, 2025
DOI: https://doi.org/10.1103/mxzl-3ld7
Abstract
This experimental study examines the dynamics of the shock-induced breakup of a liquid drop within the shear-strip breakup regime. The interaction of the shock wave with the interface leads to its reflection and transmission. The reflected shock wave from the windward side of the drop, combined with the merging of the Mach stem at the downstream of the leeward side, creates an uneven pressure distribution across the drop. The compression of the windward face results in the formation of a surface wave, which is intensified by the shearing of flow. This process redistributes the liquid across the drop, resulting in the formation of a dense core and a peripheral meridional zone. With increasing strength of the Mach stem, a surface wave develops on the leeward side. The evolution of the surface wave is found to be governed by a shear-dominated cascading instability mechanism, suggesting the presence of multiscale instability. The surface wave on the windward and leeward sides collides during the drop deformation, transferring its momentum in the cross-stream direction. The acceleration of flow into the azimuthal ring causes corrugations to appear in the transverse direction. These corrugations are found to be governed by the Rayleigh-Taylor instability mechanism. These corrugations are further developed into fingers. These dynamics result in the identification of two submodes: ligament and cellular. In the ligament breakup mode, the radial fingers elongate streamwise to form a ligament that breaks due to surface tension. In cellular breakdown, the fingers evolve into U-shaped structures that combine with the azimuthal ring to form cellular structures. The azimuthal ring detaches from the deforming drop as the flow accelerates through it. The coupled Rayleigh-Taylor and Rayleigh-Plateau mechanisms govern the breakup of the azimuthal ring. An additional instability in the deforming drop leads to the formation of a secondary azimuthal ring. The core deforms as the flow accelerates into it. This deformation is governed by a Rayleigh-Taylor instability mechanism.
