抄録
The promotion of jet-stream diffusion may enhance the efficiency of mechanical performance in various industrial devices such as fluid machinery and combustion equipments. Both active and passive means were applied for the control of jet streams. Our previous studies disclosed that diamond-shaped cylinder bundles produce a self-excited oscillating jet-stream flow field having multiple uniform flow-rate groups. The present visualization work deals with effects of wall concavity on flip-flop flows in a diamond-shaped cylinder bundle. It is disclosed in the efflux jet streak-lines that characteristics of flip-flop flows are different in cases of the diamond-shaped cylinder bundle without and with wall concavity, respectively.
