Empirical Protocol to Correct Laser-Diffraction Measurements from Multiple-Scattering Effects

The present work addresses the problem of multiple-scattering effects on Laser-Diffraction spray drop-size distribution measurements. The Laser-Diffraction Technique (LDT) is a rather straightforward diagnostic often used in industries and universities to characterize liquid sprays. Recent LDT equipments have been especially conceived for highly transient and dense sprays such as those encountered in car injection applications (direct gasoline injection or diesel injection). In particular, they are equipped with an optional algorithm to correct the effects of multiple-scattering that occurs when the spray density is great. However, experimental investigations of the literature reported that this algorithm was not able to treat all situations. An explanation for this could be found in the assumptions of the model that are often not satisfied by real sprays. For several years, an alternative to this approach has been explored: it consists in establishing an empirical correction protocol. In a recent approach, this empirical correction protocol received a mathematical description. The work in the present contribution generalizes this mathematical model and demonstrates that it is able to describe the influence of multiplescattering for other working conditions. The sprays investigated here are produced by a three-jet gasoline direct injection device. We found that the mathematical model was adaptable to this case. Therefore, the present empirical correction protocol appears to be easily applicable and should be recommended at least to test a theoretical model or at most to replace it