Emergence and dynamics of gas-accelerated liquid sheets: Insights into liquid chain formation

This study examines the behavior of liquid chain, open rim, and transitional jet–liquid chain regimes in gas-accelerated liquid micro-sheets using experimentally validated numerical simulations. The simulations employ the finite volume method with a volume-of-fluid framework to resolve compressible ideal gas flow impinging on a Newtonian, laminar liquid jet under atmospheric conditions. Adaptive mesh refinement is used to resolve the gas–liquid interface. The validation of the model is performed based on a purpose-built experimental setup over the range of gas–liquid momentum flux ratios 0.03<MFR<2.6, and Weber numbers, evaluated at the liquid capillary inlet, 3.8<We<49, achieving an agreement of the simulated liquid-sheet shape below experimental uncertainty. Three typical flow regimes are explained by the interplay of gas momentum, liquid inertia, and surface tension, scaled by the liquid-sheet rim Weber number (Werim), based on rim curvature and the rim transverse velocity. The transitional jet–liquid chain regime occurs at Werim<0.1, where the surface tension dominates, resulting in only a slight change of the liquid jet cross section. In the liquid chain regime (0.1<Werim<1) gas inertia forms the sheet, then surface tension bends the rim inward, and transverse momentum transfer forms an orthogonal secondary link. In the open rim regime (Werim>2), dominant rim inertia prevents sheet closure. The Weber number (We), based on the nozzle inlet parameters, can predict the liquid chain regime in the range 1.5 ≲ MFR We0.84 ≲ 4. This relation provides practical guidance for stable liquid chain operation.