Experimental and Computational Study of Underexpanded Free Jets Produced by Canned Air Dusters

Compressed air dusters, commonly known as canned air or electronic dusters, operate by releasing high-pressure gas through a small diameter nozzle, producing an axi-symmetric jet. As trivial as their common uses may seem, the flow produced by these cans can be highly complex. This study explores the educational and experimental value of a low-cost and widely accessible setup and method for visualizing and interacting with underexpanded jets produced by canned air dusters. Employed Schlieren imaging and computational simulations show that the variation of the nozzle geometry robustly produces a wide range of flow phenomena: subsonic flows, underexpanded flows, and even the rare highly and extremely underexpanded flows. These results suggest that the proposed method is not only of educational value but also for future research of the lesser studied characteristics of highly and extremely underexpanded jet flows.