ABSTRACT

Within the framework of radioactive waste management, the VALIDA program, co-financed EDF/CEA, started to provide reliable data for the validation of numerical tools used to model the cooling of spent nuclear-fuel containers in dry storage facilities. The design of such facilities implies thermal-aeraulic calculations in order to predict containers and wall temperatures. VALIDA experiments were carried out in this way on a finite circular heated cylinder mounted vertically in a wind tunnel cooled by a cross-flow air circulation. The results show that the airflow pattern strongly depends on the ratio of the buoyancy to the inertia force on the one hand and on the upstream turbulence intensity on the other hand. Zones where experimental convective transfers involve predominately forced or natural convection are distinguished thanks to established heat transfer correlations. A dimensionless Bo* number is defined to characterize the experimental flow regimes obtained.