Thermal Analysis by hcj

VIEWS: 0 PAGES: 10

									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
                               2
    k2=20 W/m-K                        2 cm
      Channels are 3 cm
       in diameter         1                   15
                                               cm
               1 cm
                                   10
q=104 W/m2                         cm
        In-Class Problems h=1000 W/m2-K
                           Tb=50 C
  k1=1 W/m-K
                           2
  k2=20 W/m-K                      2 cm
    Channels are 3
     cm in diameter    1                   15
                                           cm
                1 cm
                               10
q=104 W/m2                     cm

								
To top