joule heating of material with anisotropic electric conducti
joule heating of material with anisotropic electric conducti
I am new user of Elmer. I want to calculate joule heating for an electric anisotropic material. However I cannot obtain the result if I use the anisotropic parameter. Can I calculate the joule heating of this situation by using Elmer.We will attach the sif file used for reference so please advise.
- Attachments
-
- study2.txt
- (5.3 KiB) Downloaded 373 times
Re: joule heating of material with anisotropic electric conducti
Hi mahichihi,
Yes Electric conductivity can be represented as anisotropic tensor, as it is writtten in the snippet of source code of StatCurrentSolve.F90.
Now, in the Material n section of your solver input file you need to write a 3*3 matrix in three rows separated by \ as for Elmer sif convention as:
Since you are expressing electric conductivity and heat conductivity as orthotropic tensors, what would happen if you simply write them as:
Yours Sincerely,
Anil Kunwar
Yes Electric conductivity can be represented as anisotropic tensor, as it is writtten in the snippet of source code of StatCurrentSolve.F90.
Code: Select all
!------------------------------------------------------------------------------
! Read conductivity values (might be a tensor)
!------------------------------------------------------------------------------
CALL ListGetRealArray( Model % Materials(k) % Values, &
'Electric Conductivity', Cwrk, n, NodeIndexes )
Conductivity = 0.0d0
IF ( SIZE(Cwrk,1) == 1 ) THEN
DO i=1,3
Conductivity( i,i,1:n ) = Cwrk( 1,1,1:n )
END DO
ELSE IF ( SIZE(Cwrk,2) == 1 ) THEN
DO i=1,MIN(3,SIZE(Cwrk,1))
Conductivity(i,i,1:n) = Cwrk(i,1,1:n)
END DO
ELSE
DO i=1,MIN(3,SIZE(Cwrk,1))
DO j=1,MIN(3,SIZE(Cwrk,2))
Conductivity( i,j,1:n ) = Cwrk(i,j,1:n)
END DO
END DO
END IF
Code: Select all
Material 1
Name = "Material 1"
Reference Temperature = 290
!Electric Conductivity = Variable Temperature;REAL;290 9.26e11;1290 8.34e11 ;END
Electric Conductivity (3,3) = Real \
8.34e11 0 0 \
0 8.34e11 0 \
0 0 8.34e9
!Heat Conductivity = 13.4e6
Heat Conductivity (3,3) = Real \
13.4e6 0 0 \
0 13.4e6 0 \
0 0 13.4e4
Density = 8400e-18
End
Code: Select all
Material 1
...
Electric Conductivity (3) = Real 8.34e11 8.34e11 8.34e11
...
Heat Conductivity (3) = Real 13.4e6 13.4e6 13.4e6
...
End
Yours Sincerely,
Anil Kunwar
Last edited by annier on 20 Feb 2017, 02:10, edited 1 time in total.
Anil Kunwar
Faculty of Mechanical Engineering, Silesian University of Technology, Gliwice
Faculty of Mechanical Engineering, Silesian University of Technology, Gliwice
Re: joule heating of material with anisotropic electric conducti
Hi annier. Thank you for your reply.
I retried calculation at the advice of you. As a result, I could obtain the joule heating, volume current and potential, but th temperature remained the initial condition.I will attach the result.
Please point out if there are still points to improve
Note that, I wrote 3*3 matrix following formula;
Electric Conductivity(3,3)=REAL 8.34e11 0 0 \
0 8.34e11 0 \
0 0 8.34e9
Heat Conductivity(3,3)=REAL 3.4e6 0 0 \
0 13.4e6 0 \
0 0 13.4e4
since if I use your suggestion the Elmer solver outputs an error message.
ERROR:: SectionContents: Problem reading real keyword: electric conductivity: \ 8.34e11 0 0.
Yours Sincerely,
Mahichihi
I retried calculation at the advice of you. As a result, I could obtain the joule heating, volume current and potential, but th temperature remained the initial condition.I will attach the result.
Please point out if there are still points to improve
Note that, I wrote 3*3 matrix following formula;
Electric Conductivity(3,3)=REAL 8.34e11 0 0 \
0 8.34e11 0 \
0 0 8.34e9
Heat Conductivity(3,3)=REAL 3.4e6 0 0 \
0 13.4e6 0 \
0 0 13.4e4
since if I use your suggestion the Elmer solver outputs an error message.
ERROR:: SectionContents: Problem reading real keyword: electric conductivity: \ 8.34e11 0 0.
Yours Sincerely,
Mahichihi
- Attachments
-
- temperature
- temperature.png (9.23 KiB) Viewed 6951 times
-
- potential
- potential.png (17.04 KiB) Viewed 6951 times
-
- Joule heating
- joule heating.png (31.41 KiB) Viewed 6951 times
Re: joule heating of material with anisotropic electric conducti
Hi Mahichihi,
Please put one \ in the first line after Real when representing the anisotropic tensor matrix as in:
I have updated it in the second post as well . The numbers of the matrix follow the next line of the sif file.
Yours Sincerely,
Anil Kunwar
Please put one \ in the first line after Real when representing the anisotropic tensor matrix as in:
Code: Select all
Material 1
Electric Conductivity (3,3) = Real \
8.34e11 0 0 \
0 8.34e11 0 \
0 0 8.34e9
...
Heat Conductivity (3,3) = Real \
13.4e6 0 0 \
0 13.4e6 0 \
0 0 13.4e4
...
End
Yours Sincerely,
Anil Kunwar
Anil Kunwar
Faculty of Mechanical Engineering, Silesian University of Technology, Gliwice
Faculty of Mechanical Engineering, Silesian University of Technology, Gliwice
Re: joule heating of material with anisotropic electric conducti
Hi annier.
I modified the conductivity tensor according to your advice as follows
however the results were same as before.
I still can not understand why this kind of thing happens.
Do i miss up anything?
Sincerely yours
Mahichihi
I modified the conductivity tensor according to your advice as follows
Code: Select all
Material 1
Name = "Material 1"
Reference Temperature = 290
!Electric Conductivity = Variable Temperature; Real MATC "(-9E+07)tx+1E+12"
!Electric Conductivity = Variable Temperature;real;290 9.26e11;1290 8.34e11;end
!Heat Conductivity = 13.4e6
Electric Conductivity (3,3) = Real \
8.34e11 0 0 \
0 8.34e11 0 \
0 0 8.34e9
Heat Conductivity (3,3) = Real \
13.4e6 0 0 \
0 13.4e6 0 \
0 0 13.4e4
Density = 8400e-18
End
I still can not understand why this kind of thing happens.
Do i miss up anything?
Sincerely yours
Mahichihi
Re: joule heating of material with anisotropic electric conducti
Hi mahichihi,
The two Electrical conductivity elements of the matrix E_11, E_22,are equal that is 8.34E+11. Make them different to visualize anisotropic effect.
The same reasoning with heat conductivity. In numerical simulation, there are many things we need to adjust.
Yours Sincerely,
Anil Kunwar
The two Electrical conductivity elements of the matrix E_11, E_22,are equal that is 8.34E+11. Make them different to visualize anisotropic effect.
The same reasoning with heat conductivity. In numerical simulation, there are many things we need to adjust.
Yours Sincerely,
Anil Kunwar
Last edited by annier on 28 Feb 2017, 07:35, edited 1 time in total.
Anil Kunwar
Faculty of Mechanical Engineering, Silesian University of Technology, Gliwice
Faculty of Mechanical Engineering, Silesian University of Technology, Gliwice
-
- Posts: 196
- Joined: 29 Sep 2011, 12:25
- Antispam: Yes
Re: joule heating of material with anisotropic electric conducti
Hi there,
what is the dimension (meters/millimeters) of your geometry? Often you don't see a change in some quantity when there is a scaling mistake.
For example when you want the geometry to be in millimeters, but you got meters then the heat source is simply not big enough to cause a significant change in temperature.
Then you would need to add a Coordinate Scaling = 1.e-3 in the first section of the sif file.
This is just a wild guess tho.
best regards
Franz
what is the dimension (meters/millimeters) of your geometry? Often you don't see a change in some quantity when there is a scaling mistake.
For example when you want the geometry to be in millimeters, but you got meters then the heat source is simply not big enough to cause a significant change in temperature.
Then you would need to add a Coordinate Scaling = 1.e-3 in the first section of the sif file.
This is just a wild guess tho.
best regards
Franz
Re: joule heating of material with anisotropic electric conducti
Hi annier.
My question is, rather than not be able to see the anisotropy, is that the temperature can not be calculated at why calculated Joule heat. For example, if the electric conductivity is isotropic and incorporates anisotropy in the thermal conductivity, the temperature can be calculated.
The following is the sif file used.
Sincerely yours
Mahichihi
My question is, rather than not be able to see the anisotropy, is that the temperature can not be calculated at why calculated Joule heat. For example, if the electric conductivity is isotropic and incorporates anisotropy in the thermal conductivity, the temperature can be calculated.
The following is the sif file used.
Code: Select all
Material 1
Name = "Material 1"
Reference Temperature = 290
!Electric Conductivity = Variable Temperature; Real MATC "(-9E+07)tx+1E+12"
!Electric Conductivity = Variable Temperature;real;290 9.26e11;1290 8.34e11;end
!Electric Conductivity (3,3) = Real \
! 8.34e11 0 0 \
! 0 8.34e11 0 \
! 0 0 8.34e9
Electric Conductivity = 8.34e11
!Heat Conductivity = 13.4e6
Heat Conductivity (3,3) = Real \
13.4e6 0 0 \
0 13.4e6 0 \
0 0 13.4e4
Density = 8400e-18
End
Mahichihi
- Attachments
-
- temperature distribution
- temperature.png (17.17 KiB) Viewed 6914 times
Re: joule heating of material with anisotropic electric conducti
Hi Franz.
Thank you for your comment.
My geometry has dimensions um. So I rewrie the physical constants.
For examaple, on the Heat Conductivity, I employ 13.4e6 pW/ um K instead of 13.4 W/m K.
Sincerely yours
Mahichihi
Thank you for your comment.
My geometry has dimensions um. So I rewrie the physical constants.
For examaple, on the Heat Conductivity, I employ 13.4e6 pW/ um K instead of 13.4 W/m K.
Sincerely yours
Mahichihi
Re: joule heating of material with anisotropic electric conducti
Hi,
did you also adjust the vacuum permittivity (it is in As/Vm by default)?
I assume that you know what you are doing when working in um whereas Elmer assumes m by default. You will have to check all parameters, material properties etc. very carefully...
Alternatively, say
Coordinate Scaling = 1e-6
in the Simulation section, as Franz suggested.
HTH,
Matthias
did you also adjust the vacuum permittivity (it is in As/Vm by default)?
I assume that you know what you are doing when working in um whereas Elmer assumes m by default. You will have to check all parameters, material properties etc. very carefully...
Alternatively, say
Coordinate Scaling = 1e-6
in the Simulation section, as Franz suggested.
HTH,
Matthias