CFD _CAST-Tilted -New mesh generation E. Da Riva

Summary E. Da Riva 1.Mesh generation 2.First results 3.Thermal b.c. improvement?

E. Da Riva Symmetry Focus on modeling and understanding physical phenomena (instead of reproducing the exact experimental number of moles) Interconnection between cold-bores neglected (Adiabatic in most simulations + Horizontal -> small influence on natural convection) Axisymmetric fluid domain -> good mesh Symmetry plane b.c. -> better exploitation of computational resources No changes for the thermal b.c. MESH: CAST-15Feb2012.msh cells

E. Da Riva Wall meshing Cell thickness close to wall: 50 μm Grow ratio: 1.2 # layers: 10 Cell longitudinal size increasing from 1 mm at the windows up to 15 mm at 3.5 m from the cold-bore center

E. Da Riva Polypropylene window Thicker window with fake non-isotropic conductivity did not work. Propylene window modeled with real thickness and conductivity. Non-conformal interface between steel net and poplypropylene.

E. Da Riva First results Ideal Gas. Pressure 37.1 mbar Hot window (T w =63 K, T CB =1.798K)

E. Da Riva MFB Fluent Star-ccm+

E. Da Riva MFB Fluent Star-ccm+ Sleeve not taken into account in the Star-ccm+ simulations. b.c. T = K

E. Da Riva First results Ideal Gas. Pressure 37.1 mbar Hot window (T w =63 K, T CB =1.798K)

E. Da Riva Density along axis

E. Da Riva Thermal b.c. improvement?