For this purpose, a roadmap of experiments, supported by Computational Fluid Dynamics (CFD) calculations has been developed: a) Experiments in H2O, Hg and PbBi Experiments using water (hydraulically similar to PbBi) have been performed at UCL (B). The aim was to optimize the design of the target nozzle taking into account the core configuration. First liquid-metal experiments with Hg were performed at IPUL (Lv) in 2001. Validation experiments with PbBi in the KALLA-loop at FZK (G) were performed in September 2004. These results showed the principle possibility to create a suitable flow configuration in a free surface target nozzle. To fine tune the nozzle design, a second campaign of water experiments is being performed at UCL within the frame of the IP-Eurotrans project. These will be again be followed by validation experiments with LBE in the KALLA-lab at FZK. The flow pattern in the water experiments is characterized in detail to serve as input for the validation of CFD codes. b) CFD calculations
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An in-depth assessment using the currently available CFD codes has shown that the flow pattern is the result of a complex interaction between turbulence and free surface features. Our goal is to develop a code which combines advanced turbulence and free-surface features, by implementing the LES turbulence model in the state-of-the-art VOF code COMFLO (RUG, NL). The final goal of efforts concerning code development and validation is to obtain a suitable tool for numerical simulation of the influence of the proton beam heating on the target nozzle which cannot be simulated experimentally at this stage. A first very rough assessment with a far from optimised calculation tool has shown promising results. However, since this is a critical point in the windowless | |