An experimental investigation of resonant heat transfer enhancement in grooved channels

Quantitative Visualization of Heat Transfer in Oscillatory and Pulsatile Flows

“…In laminar, steady-state conditions there is virtually no exchange of fluid between these two regions. The results of Patera and Mikic (1986), Karniadakis et al (1987), Greiner et al (1990) and Greiner (1991) showed that selfsustained oscillations develop in such flow configurations at a relatively low Reynolds number in the transitional regime, and the interaction of separated flow with imposed unsteadiness leads to lateral convective motions that result in overall transport enhancement.…”

Mass‐transfer enhancement in a wavy‐walled tube by imposed fluid oscillation

“…For example, no resonant enhancement occurs for pulsatile flow in the plane channel because no velocity perpendicular to the main stream is generated, although the Tollmien-Schlichting waves exist. To identify the above numerical results, Greiner (1991) carried out the experimental study in the grooved channel with a small cavity. He confirmed that small fluid oscillations at the Tollmien-Schlichting frequency increase dramatically the amplitude of the instability, even for Reynolds numbers below the critical value at the onset of self-sustained oscillations, and thus enhance heat transfer.…”

Experimental investigation of fluid flow in horizontal pipes system of various cross-section geometries

“…It was concluded that the head losses of the downward sloping pipe flow are always lower than the head losses of the horizontal flow and these are always lower than the head losses of the upward sloping pipe Work has also been reported on experimental investigations in grooved flow geometries. Greiner [5] investigated the water flow through ducts with periodically grooved elements located into one wall. He found that while the absolute level of transport depends on the thermal and geometric conditions, the enhancement gained from 20% flow rate modulation is fairly insensitive to them.…”