Critical heat transfer problems are discussed in the context of the operation of a spallation source target, which represents a first demonstration of the feasibility of an innovative concept for generating energy usi...Critical heat transfer problems are discussed in the context of the operation of a spallation source target, which represents a first demonstration of the feasibility of an innovative concept for generating energy using a particle accelerator. Within the framework of the umbrella project MEGAPIE, an R&D support group was organized to take responsibility for target cooling. This involved the use of advanced numerical methods - Computational Fluid Dynamics (CFD) and Finite Element Method (FEM) - validated against suitable experimental data, and by means of appropriate benchmarking exercises. The design studies using CFD resulted in an optimum flow configuration being defined for the coolant circulation. Flow visualization tests were undertaken using a glass/water test section, with the velocity field mapped using optical and ultrasonic measuring techniques. These were followed by heat transfer tests, using the actual target materials (lead-bismuth-eutectic coolant and steel confinement). Further CFD/FEM work to analyze operational transients and accident sequences was also carded out, and is described in the paper.展开更多
文摘Critical heat transfer problems are discussed in the context of the operation of a spallation source target, which represents a first demonstration of the feasibility of an innovative concept for generating energy using a particle accelerator. Within the framework of the umbrella project MEGAPIE, an R&D support group was organized to take responsibility for target cooling. This involved the use of advanced numerical methods - Computational Fluid Dynamics (CFD) and Finite Element Method (FEM) - validated against suitable experimental data, and by means of appropriate benchmarking exercises. The design studies using CFD resulted in an optimum flow configuration being defined for the coolant circulation. Flow visualization tests were undertaken using a glass/water test section, with the velocity field mapped using optical and ultrasonic measuring techniques. These were followed by heat transfer tests, using the actual target materials (lead-bismuth-eutectic coolant and steel confinement). Further CFD/FEM work to analyze operational transients and accident sequences was also carded out, and is described in the paper.