Abstract
The phenomena of heat transfer enhancement by turbulent coherent structures are indispensable to make high performance in heat transfer with a small pressure loss. Not only time-mean thermo- and fluid-dynamics but also unsteady and sequential thermo-fluid phenomena are very important to study and control the phenomena. The most percentage of heat transfer enhancement were given birth for very short time period, when the turbulent structures just came and make effect on the heat transfer field. But the time-dependent correlations between unsteady fluid-heat transfer fields are still unknown. In this study, the three-dimensional velocity measurement system by color image processing would be improved with unsteady multi-color fields and various detecting optical devices with features, and the unsteady enhancement processes would be investigated when the periodic vortex from cylinder were got collapse on a plane.
