Characteristics of Sheet Formed by Collision of Two Elliptical Jets at Short Impact Distance

Abstract

The research on characteristics of impinging jet has a long history and focuses mainly on the circular jets, whereas the impingement of noncircular jets, such as elliptical jets, receives much less attention. This paper investigated liquid sheet resulting from the oblique collision of two elliptical jets at short impact distance. The elliptical liquid jets contract and collide obliquely at impact point, forming a sheet in the form of a leaf bounded by a thicker rim. An improved theoretical model, taking jet contraction into account, for two elliptical impinging jets is established. The sheet features are obtained by combining the conservation equations between the liquid jet and sheet with the force balance equations of the sheet rim. The calculated sheet shapes are compared with the experiments, and the results show good agreement. The experimental results also indicate that the liquid sheet formed by elliptical jets tends to be larger and more unstable than that formed by circular jets. Based on the model, the effects of axial ratio and impact distance on the sheet characteristics, such as sheet shape and thickness, are also studied.