Abstract
In this paper, it was reported that simulation design study about gas process unit, such as process gas reactor, heat exchangers and heat conditioner, for one of the heat utilization system components development of High Temperature Gas-cooled Reactor (HTGR). In simulating precisely the heat transfer control characteristics of the gas-mixing unit, a good model for turbulent mixing process of some velocity ratios is a key issue. Therefore, we have been proceeding to develop the newly CFD code. This code using algebraic Reynolds stress model has been reasonably predicted about complex turbulent flows such as flow separation in a rectangular duct with 90-degree sharp turn and strong anisotropic flow in straight duct with roughened walls. However, it has not enough been validated for gas-mixing turbulent flow. We have a lack of detailed knowledge and experimental data on the turbulent gas process in the unit. Hence, as the first step to make the air mixing process in gas unit clear, we have made an preliminary experimental study on turbulent mixing using the equipment with flow control door arranged some velocity ratios and a heating core. Flow visualization was carried out by using particle image velocimetry (PIV). As a result of this study, it was obtained representative velocity distribution data and turbulent kinetic energy distributions about separation and gas mixing section in the equipment, which is important for unit performance. Furthermore, it was found that production of turbulence in the unit were strongly formed by unsteadily long separation flow between velocity ratios and small scale vortices induced to the tip of door.
