Speaker
Chiara Mistrangelo
(Institute for Nuclear and Energy Technologies)
Description
In 2008-2009 experiments have been performed to investigate liquid metal magnetohydrodynamic (MHD) flows in a scaled mock-up of a helium cooled lead lithium (HCLL) blanket. In order to improve the mechanical stiffness of the blanket module the design of the stiffening plate between two hydraulically connected breeder units (BUs) has been later modified. In the former design the liquid metal passed from one BU to the adjacent one by flowing through a slot that extended along the entire width of the BU. In the most recent design this opening has been replaced by a series of smaller gaps. Therefore the velocity increases locally owing to the reduced cross-section along the flow path and the liquid metal has to expand along magnetic field lines to enter the next BU. These flow conditions are known to create additional pressure losses as a result of the occurrence of 3D MHD phenomena and significant inertia effects.
In order to quantify the influence of the design modifications described above, the available test section has been adapted to the new design features. Experiments have been performed to record pressure distribution in the new mock-up in a wide range of flow parameters and data have been compared with results obtained by using the former test section.
Experimental results show that these design modifications near the first wall lead to a local increase of pressure drop by a factor 3-3.5 compared to previous data. As a consequence the total pressure drop becomes larger too. Additional pressure losses near the first wall, where the fluid expands and contracts along magnetic field lines, seem to be mainly related to inertia effects confined in boundary layers along walls parallel to the magnetic field.
Co-authors
Chiara Mistrangelo
(Institute for Nuclear and Energy Technologies, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany)
Christina Koehly
(Institute for Nuclear and Energy Technologies, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany)
Leo Buhler
(Institute for Nuclear and Energy Technologies, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany)
