Effect of skewness on the characteristics of impinging jet atomizers

Characteristics of partially impinging jet atomizers (skew jets) in the context of application in liquid propulsion systems are studied in this article. Considering the fact that practical impinging injectors are likely to have skewness (partial impingement), an experimental study is made to understand the behavior of such jets, using water as a simulant. In perfectly impinging doublet, a high aspect ratio ellipse-like mass distribution pattern is obtained with the major axis normal to the plane of two jets, whereas in skewed jets, the major axis turns from its normal position. A simple correlation is obtained that shows that this angle of turn is a function of skewness fraction and impingement angle only and is independent of injection velocity. Experimental data from both mass distribution and photographic technique validate this prediction. Mean drop size of spray is found to decrease as skewness is increased. This may be the combined effect of the elongation of the liquid sheet and perhaps the shearing of the liquid sheet at the point of impingement. Hence skewness turns out to be an important parameter in controlling mass distribution and drop size