The present study deals with a slot fluid jet impinging onto
an electrically heated circular cylinder in water. The continuous
and synthetic jets were tested. The slot nozzle width was
0.36 mm, the cylinder diameter was 1.2 mm, and the
cylinder-to-nozzle spacing, related to the slot width, was 5–21.
The Reynolds numbers based on the nozzle width ranged 35–
170. The Laser-Induced Fluorescence (LIF) visualization
revealed a dominant flow separation occurring on the windward
cylinder side for both continuous and synthetic jets. The flow
around the leeward cylinder side is completely absent. It is
attributed to the effects of the mini scale and low Reynolds
numbers. An increase of the Reynolds numbers changes flow
pattern from a steady jet-flow separation to a vortex shedding
wake-flow regime. Heat transfer experiments were validated in
a natural convection regime. An enhancement of average
Nusselt numbers by 4.2–6.2 times by means of the synthetic
jets was quantified by comparison with the natural convection
regime. A correlation for the average Nusselt number was
proposed for both continuous and synthetic jets.
Papers presented to the 12th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Costa de Sol, Spain on 11-13 July 2016.