Transitional flow patterns behind a backstep with porous-based fluid injection

Transient flame spread during convective ignition of solid fuel in a sudden-expansion combustor

“…Note that the fuel vapor is drawn by the large vortices and behaves as a weak upward flow. The upward flow is found to neutralize the upstream flow that is induced by the vortices, which is consistent with results from the study of transpiration cooling in a suddenexpansion channel [40]. Consequently, the recirculation structure is relatively insignificant comparing to that in the non-reacting case.…”

Cooling transients in a sudden-expansion channel with varied rates of wall transpiration

“…5. Note that the four patterns correspond respectively to patterns A, B, C, and D in [12], in which detailed analyses of the flow structures are demonstrated.…”

“…Two maxima of the Stanton number occur at the beginning of the coolant injection; one is near the step corner, and the other locates at the reattachment zone. The former is attributed to the greater coolant injection induced by the low pressure (the low-pressure center locates at x = 2.5-3.5 H) [12]. Accordingly, the temperature difference across the porous sheet is increased.…”

“…The aluminum oxide (Al 2 O 3 ) powder is seeded into the flow when conducting LDV diagnostics. Further details about the LDV measurement, including its uncertainty analysis, are available in [12]. Total 40 thermocouples (K-type, 125 lm) are attached to 20 stages at both sides of the porous sheet to measure the temperature of the bottom wall, while the flow temperature is accessed via a tiny probe installed with another thermocouple (K-type, 25 lm).…”

“…Furthermore, four distinct flow patterns were categorized by Yang et al . [12] by increasing the wall injection velocity ratio gradually.…”