Experimental Study of the Near Field of a Breaking Liquid Sheet

An experimental study has been performed to improve the understanding of the initial air/liquid interaction in a breaking water sheet. This study is focused in the near field close to the exit slit, because it is in this region where instabilities develop and grow, leading to the sheet break-up. Planar laser-induced fluorescence has been used to visualize the air flow field. Acetone vapour seeded in the air streams has been used as fluorescent tracer. Mie scattering from the liquid sheet and water droplets, together with the acetone fluorescence signal has enabled simultaneous determination of the instantaneous water sheet location and the air flow structure. Images have been acquired slicing the flow both longitudinally and transversally. Particle imaging velocimetry measurements have been obtained to determine the air velocity both in absence and in presence of the water sheet.