Ozone tagging for unseeded velocimetry

This paper builds upon our discovery of a new method called ozone tagging velocimetry (OTV) for performing unseeded molecular velocimetry. A major advantage of OTV is that the measurement may be performed without the requirement of seeding for subsonic and supersonic air flows. The OTV approach consists of tagging the flow with ozone produced by an ArF laser pulse. The stable ozone tag is convected with the flow, and subsequently observed using laser-induced fluorescence by a delayed KrF laser pulse. We outline several considerations for the implementation of ozone tagging velocimetry, and present results demonstrating its practice in controlled laboratory experiments.