Possibilities and limitations of cfd simulation for flashing flow scenarios in nuclear applications


Possibilities and limitations of cfd simulation for flashing flow scenarios in nuclear applications

Liao, Y.; Lucas, D.

The flashing phenomenon is relevant to nuclear safety analysis for example by loss of coolant accident and safety release scenarios. It has been studied intensively by means of experiments and simulations with system codes, but CFD simulation is still at the embryo stage. Rapid increasing computer speed makes it possible to apply the CFD technology in such complex flow situations. Nevertheless, a thorough evaluation on the limitation and restriction is still missing, which is however indispensable for the further development. In the present work, the commonly used two-fluid model with different mono-disperse assumptions are used to simulate various flashing scenarios. With the help of available experimental data, the results are evaluated and limitations are discussed. A poly-disperse method is found necessary for a reliable prediction of mean bubble size and phase distribution. First attempts to trace the evolution of bubble size distribution by means of poly-disperse simulations are made.

Keywords: Flashing; CFD simulation; Two-Fluid-Model; Mono-disperse; Poly-disperse

Permalink: https://www.hzdr.de/publications/Publ-24558
Publ.-Id: 24558