自激振荡脉冲射流强化换热实验研究

Experimental Investigation of Intensified Heat Exchange Based on Self-excited Oscillating Pulse Jets

对自激振荡射流强化换热的机理进行了初步探讨,并对有无共振腔时的换热情况进行了对比实验。实验中发现,由Helmholtz共振腔产生的自激振荡脉冲射流增强了管内流体的掺混,破坏了边界层,从而达到了强化换热的目的。实验中还发现,当共振腔两端的压差增大时,将产生更为强烈的脉动流,明显地提高流体的紊流程度,从而强化了管内流动换热。

A preliminary exploratory study was conducted of the mechanism of self-excited oscillating pulse jets-based intensified heat exchange. Furthermore, a contrast test was performed of the heat exchange conditions with or without a resonant cavity. Through tests it is found that the self-excited oscillating pulse jets produced by a Helmholtz resonant cavity have intensified the dilution mixing of fluids in a tube, thus destroying boundary layers and resulting in an intensified heat exchange. During the tests it has also been discovered that the increase in pressure difference at the two ends of the resonant cavity will generate more intensified pulse flows, significantly enhancing the turbulence degree of fluids and, as a result, intensifying the in-tube flow heat exchange.