Experimental analysis of a non-isothermal confined impinging single plume using time-resolved particle image velocimetry and planar laser induced fluorescence measurements

Abstract

In this study, the experimental results of the flow behavior of a non-isothermal confined impinging single plume were analyzed. Experimental measurements were performed in the upper plenum of a high-temperature gas-cooled reactor (HTGR) that was scaled, designed, and assembled at Texas A&M University. The goal was to investigate flow mixing, thermal stratification, and plume impingement in the upper plenum of the HTGR under a loss-of-forced-coolant accident and provide a high-fidelity experimental database for validating computational fluid dynamics (CFD) and system codes. Time-resolved particle image velocimetry (TR-PIV) and planar laser-induced fluorescence (P-LIF) measurements were performed in the central plane of the plume flow in the upper plenum. A total power of 0.4 kW of heat was applied to the system. Convergence was achieved for the statistical results from the TR-PIV and P-LIF snapshots. The TR-PIV velocity vectors presented statistical characteristics of the plume flow, such as the mean velocity, root-mean-square fluctuating velocity, and Reynolds stress. The results revealed that the flow reached the maximum velocity far from the jet inlet at y/Dj=2. Furthermore, two-point velocity cross-correlation was performed on the TR-PIV velocity vector fields. Finally, the statistical results were calculated from the P-LIF temperature snapshots and the mean temperature. Furthermore, the temperature profiles were plotted. It was observed that the flow reached the maximum temperature near the plume inlet and decreased downstream.