D203 VELOCITY AND TEMPERATURE MEASUREMENTS IN HEAT TRANSFER OF SWIRLING IMPINGING JETS(Temperature measurement)

The turbulent heat transfer mechanism of a swirling impinging jet in the stagnation region was experimentally investigated, using a combined technique of particle image velocimetry (PIV) and laser induced fluorescence (LIF) for the simultaneous measurements of velocity and temperature fields. Instantaneous flow fields were visualized quantitatively to detect the turbulent heat flux. At the stagnation region, the flow near the heated surface was mixed intermittently by reverse flows toward upstream and spatial distributions of temperature were well correlated with instantaneous velocity vector maps. The dynamic behavior of recirculation zones attributed to swirl number Sw and the impinging distance mainly determined the turbulent heat transfer.