Others have mentioned the "air curtain" name for the flow of air itself. A space enclosed by 3 solid walls and an air curtain, (plus ceiling and floor, though ceiling often contains elaborate ventilation arrangements), is called a "laminar flow hood." They're often used as one of several layers of containment in working with hazardous vapors or infectious diseases.

An air curtain by itself might be used to reduce heat transfer as by helping keep the expensive warm air in a building.