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# 3d_contact

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# 3d_contact   { 3D_CONTACT.PDE

This problem shows the use of a contact resistance boundary between layers in 3D.

The resistance model is applied to the entire boundary surface.

See 3D_CONTACT_REGION.PDE for restriction of the resistance model to a single region.

(This is a modification of problem 3D_BRICKS.PDE).

}

title 'steady-state 3D heat conduction with Contact Resistance'

select

regrid=off { use fixed grid }

coordinates

cartesian3

variables

Tp

definitions

long = 1

wide = 1

K                           { thermal conductivity -- values supplied later }

Q = 10*exp(-x^2-y^2-z^2)   { Thermal source }

e = 0.01                   {'epsilon' offset to avoid plotting on discontinuities }

initial values

Tp = 0.

equations

Tp : div(k*grad(Tp)) + Q = 0 { the heat equation }

extrusion z = -long,0,long     { divide Z into two layers }

boundaries

surface 1 value(Tp)=0       { fix bottom surface temp }

surface 2 contact(tp)=jump(tp)/10   { THE CONTACT RESISTANCE }

surface 3 value(Tp)=0       { fix top surface temp }

Region 1           { define full domain boundary in base plane }

layer 1 k=1             { bottom right brick }

layer 2 k=0.1           { top right brick }

start(-wide,-wide)

value(Tp) = 0         { fix all side temps }

line to (wide,-wide)   { walk outer boundary in base plane }

to (wide,wide)

to (-wide,wide)

to close

Region 2           { overlay a second region in left half }

layer 1 k=0.2           { bottom left brick }

layer 2 k=0.4           { top left brick }

start(-wide,-wide)

line to (0,-wide)             { walk left half boundary in base plane }

to (0,wide)

to (-wide,wide)

to close

monitors

contour(Tp) on z=e as "XY Temp - Upper"

contour(Tp) on z=-e as "XY Temp - Lower"

contour(Tp) on x=e as "YZ Temp"

contour(Tp) on y=e as "ZX Temp"

elevation(Tp) from (-wide,e,e) to (wide,e,e) as "X-Axis Temp"

elevation(Tp) from (e,-wide,e) to (e,wide,e) as "Y-Axis Temp"

elevation(Tp) from (e,e,-long) to (e,e,long) as "Z-Axis Temp"

plots

contour(Tp) on z=e as "XY Temp - Upper"

contour(Tp) on z=-e as "XY Temp - Lower"

contour(Tp) on x=e as "YZ Temp"

contour(Tp) on y=e as "ZX Temp"

surface(Tp) on y=e as "ZX Temp"

elevation(Tp) from (-wide,e,e) to (wide,e,e) as "X-Axis Temp"

elevation(Tp) from (e,-wide,e) to (e,wide,e) as "Y-Axis Temp"

elevation(Tp) from (e,e,-long) to (e,e,long) as "Z-Axis Temp"

end