Validation of the beam window temperature distribution calculations of MYRRHA by means of Computational Fluid Dynamics

A feasibility design study of the proton beam window of MYRRHA, which is an interface component between an accelerator and a nuclear reactor, needs a method to be able to evaluate heat transfer characteristics of the beam window under flowing lead bismuth eutectic. Experiments were conducted by Japan Atomic Energy Agency for different inlet temperatures and different flow rates with 6 kW as maximum heat generation. This Master Thesis investigates if RANS equations implemented in CFD codes, such as the application of the turbulent Prandtl number concept and the Reynolds analogy, can accurately predict turbulent heat transfer on the Beam Window. A sensitivity study modifying the turbulent Prandtl number was carried out to improve predictions of turbulent heat transfer. The analysis results show a general agreement between the numerical simulation and the experimental data on the shape of the curve, while calculated temperatures are generally homogeneously higher than the measured ones. The turbulent Prandtl number are quite influential on the solution. The reason is discussed in detail.