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Thermal Elements. Jake Blanchard Spring 2008. Thermal Elements. These elements calculate temperatures in solids There are 1-D, 2-D, and 3-D elements All have just 1 DOF per node
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Thermal Elements Jake Blanchard Spring 2008
Thermal Elements • These elements calculate temperatures in solids • There are 1-D, 2-D, and 3-D elements • All have just 1 DOF per node • Properties are thermal conductivity (k) for steady state analysis and density () and heat capacity (cp) for transient analyses • Boundary conditions can be temperatures, heat fluxes, or radiation • Volumetric heating is also possible
Thermal Elements in ANSYS • LINK 31 – radiation link • LINK 32 – 2-D conduction bar • LINK 33 – 3-D conduction bar • LINK 34 – convection link • PLANE 35 – 6 node triangle • PLANE 55 – 4 node quad • PLANE 75 – 4 node axisymmetric-harmonic element • PLANE 77 – 8 node quad • PLANE 78 – 8 node axisymmetric-harmonic element
More Thermal Elements • SOLID 70 – 8 node solid • SOLID 87 – 10 node tetrahedral element • SOLID 90 – 20 node hexahedral element • SHELL 57 – 4 node • SHELL 131 – 4 node layered element • SHELL 132 – 8 node layered element
Real Constants • Area, heat transfer coeff., and emissivity for links • None for planar and solid elements • Thickness for shell element (not layered) • Use “Sections” for layered elements
In-Class Problems T=0 C • k1=1 W/m-K • k2=20 W/m-K 1 2 T=100 C 1 cm 10 cm
In-Class Problems T=0 C • k1=1 W/m-K • k2=20 W/m-K q=104 W/m2 1 2 1 cm 10 cm
In-Class Problems h=1000 W/m2-K Tb=50 C • k1=1 W/m-K • k2=20 W/m-K q=104 W/m2 1 2 1 cm 10 cm
In-Class Problems T=50 C • k1=1 W/m-K • k2=20 W/m-K • Channels are 3 cm in diameter 2 2 cm 1 15 cm 1 cm 10 cm q=104 W/m2
In-Class Problems h=1000 W/m2-K Tb=50 C • k1=1 W/m-K • k2=20 W/m-K • Channels are 3 cm in diameter 2 2 cm 1 15 cm 1 cm 10 cm q=104 W/m2