# Thermodynamic problem

Hello there,

There is a problem here, a plate is given a heat to a surface point for several seconds and then is removed. I need to know a velocity of temperature change in the plate (°C/sec) and the plate steady temperature. I did not find any literature deals with the problem. You are my last resort guys.
Regards,

You can simulate this using CalculiX, if that’s what you want to know. You could use a concentrated heat flux (*CFLUX) with temperature variation defined using *AMPLITUDE. Run a transient heat transfer analysis until it reaches the steady state.

Thank you very much for your reply. As I did not use ccx for some time, I cannot find Example files: oneel20cf.

Here’s the content of that file:

``````**
**   Structure: cube subject to concentrated flux;
**   Test objective: *CFLUX
**
*NODE, NSET=Nall
1,  1.00000e+00,  1.00000e+00,  0.00000e+00
2,  1.00000e+00,  0.00000e+00,  0.00000e+00
3,  1.00000e+00,  0.00000e+00,  1.00000e+00
4,  1.00000e+00,  1.00000e+00,  1.00000e+00
5,  0.00000e+00,  1.00000e+00,  0.00000e+00
6,  0.00000e+00,  0.00000e+00,  0.00000e+00
7,  0.00000e+00,  0.00000e+00,  1.00000e+00
8,  0.00000e+00,  1.00000e+00,  1.00000e+00
9,  1.00000e+00,  5.00000e-01,  0.00000e+00
10,  1.00000e+00,  0.00000e+00,  5.00000e-01
11,  1.00000e+00,  5.00000e-01,  1.00000e+00
12,  1.00000e+00,  1.00000e+00,  5.00000e-01
13,  5.00000e-01,  1.00000e+00,  0.00000e+00
14,  5.00000e-01,  0.00000e+00,  0.00000e+00
15,  5.00000e-01,  0.00000e+00,  1.00000e+00
16,  5.00000e-01,  1.00000e+00,  1.00000e+00
17,  0.00000e+00,  5.00000e-01,  0.00000e+00
18,  0.00000e+00,  0.00000e+00,  5.00000e-01
19,  0.00000e+00,  5.00000e-01,  1.00000e+00
20,  0.00000e+00,  1.00000e+00,  5.00000e-01
*ELEMENT, TYPE=C3D20R, ELSET=Eall
1,     1,     2,     3,     4,     5,     6,     7,     8,     9,    10,
11,    12,    17,    18,    19,    20,    13,    14,    15,    16
*NSET,NSET=FIX
5,6,7,8,17,18,19,20
*INITIAL CONDITIONS,TYPE=TEMPERATURE
Nall,0.
*MATERIAL,NAME=EL
*CONDUCTIVITY
50.,0.
*PHYSICAL CONSTANTS,ABSOLUTE ZERO=-273.15,STEFAN BOLTZMANN=5.669E-8
*SOLID SECTION,ELSET=Eall,MATERIAL=EL
**
*STEP,INC=100
1.,1.
*BOUNDARY
FIX,11,11,0.
*CFLUX
1,0,10.
2,0,10.
3,0,10.
4,0,10.
9,0,-40.
10,0,-40.
11,0,-40.
12,0,-40.
*NODE PRINT,NSET=Nall
NT,RFL
*EL PRINT,ELSET=Eall
HFL
*END STEP
``````

Well, I download the file, thank you. I have a problem while

cgx -v oneel20cf.frd

there is just a cube and when I try Animate->Start nothing happens, may be I have to press something else before I do Animate->Start ? May be there is a tutorial on how to deal with thermodynamic problems on Calculix?

Did you select the field (for contour plot) first ? What exactly do you want to animate - temperature change ?

``````*NODE PRINT, NSET=…