Containment Scaling: Experimental Investigation of the Breakup of a Stratified Layer Due to a Vertical Jet from Below on Two Scales

Abstract

In the context of containment safety, the break-up of a helium (helium as substitute for hydrogen) layer due to an upward vertical jet in a confined volume was the subject of experimental investigation in two geometrically similar test facilities scaled 1:4. The high instrumentation resolution in space and time of the small-scale facility (MiniPanda) provided 2D temperature field and 1D helium concentration profile measurements well suited for CFD validation and detailed analysis of the break-up process. In order to conduct similar experiments on the scaled facilities, the boundary conditions (i.e., the jet diameter and velocity) for the experiments with two length scales have been scaled with regard to a Froude number relating the jet’s buoyancy to the jets inertia at the helium layer interface. The different flow phenomena observed in the two facilities are discussed based on experimental results.