The unsteady flows produced by consecutively pulsed, transient jets were studied using time-resolved particle image velocimetry, where two successive volumes of fluid were ejected from a nozzle into a quiescent fluid. Previous work has shown that the flows from double-pulsed jets persist to much longer times than the equivalent single-pulsed jets, suggesting powerful fluid dynamic interactions between the two ejection events. The transient jets had an exit Reynolds number of 1500 based on the nozzle diameter. The interactions between the jets was found to change significantly with the time separation between the two ejections. The instantaneous velocity distributions showed that, for shorter time intervals between the ejections, the second starting vortex was not completely formed, which was the primary difference from an individually pulsed jet. The increased momentum flux and turbulent wake of the first ejection was found to stabilize the near the flowfield of the double-pulsed jet at shorter pulse intervals by eliminating the starting vortex structure.
Time-Resolved Flowfield Measurements of Momentum-Driven Pulsed Transient Jets
AIAA Journal ; 56 , 4 ; 1434-1446
2018-01-24
13 pages
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
Time-Resolved Flow Field Measurements of Momentum Driven Pulsed, Transient Jets (AIAA 2017-1890)
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