リップ付き二次元ノズルからの噴流の諸特性について

抄録

Mixing/diffusion enhancement is one of the key technologies in various aspects, and is needed in chemical reactors, heat exchangers, burners/combustors, air conditioners and so on. Jets are known to be useful for such mixing/diffusion enhancement. Most of past studies concern a circular jet, namely, the jet from a nozzle with a circular cross section. On the other hand, we have been recently focusing our interest upon non-circular jets, to achieve more efficient mixing/diffusion enhancements. Among such non-circular jets, a plane jet has fundamental and practical importance. We research the jet from an asymmetrical two-dimensional nozzles to one side of which a lip changing lip length. Experiments are conducted at Reynolds numbers of 1,000 3,000 and 6,000. The aspect ratio of the nozzle exit is fixed to 300. And, the lip length is 0, 2.0h, 3.3h, 4.0h, 5.0h, 6.0h, 8.0h and 10h, where h denotes the height of the nozzle exit. We show turbulence-intensity in addition to mean-velocity profiles at various downstream sections, in order to reveal fundamental characteristics of the jet.