Planar Sauter Mean Diameter measurements in liquid centered swirl coaxial injector using Laser Induced Fluorescence, Mie scattering and laser diffraction techniques

• Simultaneous LIF, Mie and laser diffraction techniques for determination of absolute SMD.
• Corrections for the effect of multiple scattering in laser diffraction technique.
• Analysis of SMD distribution (Rosin-Rammler) and linear dependence of SMD from LSDS and LDT.

An experimental technique is carried out to demonstrate the measurement of planar Sauter Mean Diameter (SMD or D32) distribution in a liquid centered swirl coaxial injector (LCSC) using simultaneous measurements of Mie scattering, Planar Laser-Induced Fluorescence (PLIF) and Laser diffraction technique (LDT). Here water is used as the test fluid with addition of optimized quantities of the organic dye (Rhodamine 6 g) for PLIF measurements. Experiments are carried out at three experimental conditions with momentum flux ratios of 6.25, 12.14, and 19.95 respectively. Experiments are carried out to study the effect of dye concentration in LDT. LDT (line of sight) is corrected for multiple scattering effects. The SMD distribution obtained from Liquid Sheet Drop Sizing (LSDS) technique is calibrated using LDT (Malvern particle analyzer) that utilizes the principle of diffraction; the results obtained from both the methods are compared and analyzed using the respective histograms. The variations in the distribution of droplet diameter along the axial and radial locations in the spray field are also studied in detail.