Planar liquid volume fraction measurements in air-blast sprays using SLIPI technique with numerical corrections

Abstract

A methodology to improve the accuracy of liquid volume fraction measurement in a dense spray is presented. A combination of experimental technique, structured laser illumination and planar imaging (SLIPI) and numerical corrections is used to overcome losses in conventional planar laser-induced fluorescence (PLIF) imaging. A quantitative distribution of liquid volume fraction in a plane is obtained using corrected SLIPI–PLIF signal and PDIA (particle/droplet imaging analysis) technique. The methodology is applied to air-blast sprays for GLRs (gas to liquid mass ratio) 1, 2.5 and 4. The effect of multiple scattering is significantly high in the conventional PLIF signal imaging. A hollow cone spray geometry is observed at a GLR of 1 using the improved imaging technique. An increase in GLR from 1 to 4 leads to uniform distribution of liquid in a spray plane. A significant contribution of multiple scattering ( $$\sim$$ 62%) is observed in the conventional PLIF signal at GLR 4 along the axis of the spray. The symmetry in the SLIPI–PLIF signal is restored using the numerical corrections. The liquid volume fraction measurements from SLIPI–PLIF technique are further improved with the numerical corrections.