Numerical calculation and experimental validation of gas-accelerated flat sheet jet

This study presents the experimentally validated numerical simulation of a gas-accelerated flat sheetjet, providing valuable insights into its behaviour. The numerical calculation, based on the finite volumemethod (FVM) and volume of fluid (VOF) model, simulates a sheet jet with a gas Reynolds number of351, liquid Reynolds number of 332, Weber number of 51 and Capillary number of 0.15. A gridconvergence study confirmed that realistic behavior requires at least three computational non-adaptivecells (1.5 μm) across the radius of the sheet’s thinnest region (~5 μm), supplemented by at least twoadaptive mesh refinement (AMR) levels of the interface, giving a minimum cell size of 375 nm. Acomparison of various numerical cases for the analyzed multiphase, compressible, and unsteady flowrevealed that accuracy depends on grid resolution but is not sensitive to numerical schemes or settings.The developed numerical model demonstrates high accuracy, with the link area of the primary sheet(11,000 μm2) overestimated by 6%, the width (49.2 μm) by 6%, and the length (215 μm) underpredictedby 2%, all within the measurement uncertainty of 7%. The flow within the sheet jet was found to belaminar, without any recirculation zones.The analysis of the sheet jet dynamics identified four distinctflow regions governed by sheath gas pressure, surface tension and inertial forces, explaining theevolution of gas-accelerated flat sheet jets through successive orthogonal links forming a liquid chain.