Turbulent Characteristics of Thermal Stratified Flow with Increasing Interfacial Level in a Cylindrical Vessel

Water tests in a cylindrical vessel have been performed to investigate the turbulent transport phenomena in the mixing shear layer which moves upwardly and affects the structural integrity of the vessel and internal structures during a transient condition of a fast breeder reactor. The turbulent characteristics of the coolant adjacent to a thermally stable stratified interface have been clarified by using the technique combined with 3 beam LDV and thermocouple probe. The correlations among two-component volocities and temperature are obtained simultaneously. From the experimental results, it was found that the maximum temperature gradient can be realized in the almost laminar-like condition in which the turbulent heat fluxes in the upper and lower layers are both damped.