AbstractAn analytical study of flow in the impact region of two jets is used to develop a mathematical model that yields data for the air curtain performance. In this model”theory for the pressure difference created by an air curtain in a rectangular duct is applied to two turbulent-plane air streams injected from two opposite walls. The theory enables us to establish the quantitative influence of the jet properties and duct geometry on the pressure difference and to predict flow conditions in both inlinilies. The flows in both inlinities are considered together with the method applied for generating the streams. Air ulled to fonn the jet ill taken from an external source or is drawn In from one or both side. of the air curtain. The theory i. also extended to an air curtain fanned by a single jet. Some computed and experimental re.ults are presented.