Hello,
I never worked with the heattransfer function of Liggghts and have an problem which I'm unable to solve.
There are two partickles types inserted continously. One at (type 1) 500°C and one at (type 2) 20°C.
dt=0.00001 s
fix ftco all property/global thermalConductivity peratomtype 80. 0.038
fix ftca all property/global thermalCapacity peratomtype 449. 1700.
The radius of particletype 1 is 0.5 mm and from type 2 is 0.7 mm.
dn_dump=1000 that means 0.01s
When I simulate the model with this values, I don't see any continious heattransfer.
When I look at the dump-file, there are ony the two temperatures for particletype 2, 20°C and 500°C.
It should not be posible that an particle ist heated up in 0.01s.
I hope some one can help me.
Best regards
RobertG
kunzhang | Fri, 03/20/2015 - 18:45
In the directory of examples
In the directory of examples/LIGGGHTS/Tutorials_public, there are two heat transfer examples, you might check your in.** file with the example to see if there is any imappropriate setting in your document. Or, you could upload your full script.
Kun
RobertG | Sat, 03/21/2015 - 11:32
Thanks for your reply
Thanks for your reply kunzhang,
I implemented the code from the heatTransfer_2 Tutorial.
The only difference between the heatTransfer-part is, that im using two different particletypes.
Type 2 is inserted with 600 °C (I have done it, with the fix heat/gran initial_temperature command).
Type 1 is inserted with 600 °C and changed with the set property/atom Temp command.
Best regards
RobertG
kunzhang | Wed, 03/25/2015 - 18:37
Actually, I am working on the
Actually, I am working on the similar problem by using two types of particles, and the results look good. How did you set up and what is your thermalconductivity and thermalcapacity value? What is your total simulation time?
Kun
RobertG | Fri, 03/27/2015 - 12:57
Hello kunzhang,
Hello kunzhang,
thanks for your reply. The setup and values are described in the posts above
One temperature-value is set by the fix heat/gran initial_temperature command (for particle type 2)
The other is set with the set property/atom Temp comand (for type 1).
This command will be done every 10000 (every 0.1 s) timesteps, so that every particle which is in an certain area will get changed his temperature.
Usually im running this program for about 1 s.
But yesterday, i discovered, that there is no temperature exchange, between the two particle, at all.
My previsios error was caused, because I use the restart-function.
I hope you can help me.
Best regards
RobertG
RobertG | Fri, 03/27/2015 - 12:57
Hello kunzhang,
Hello kunzhang,
thanks for your reply. The setup and values are described in the posts above
One temperature-value is set by the fix heat/gran initial_temperature command (for particle type 2)
The other is set with the set property/atom Temp comand (for type 1).
This command will be done every 10000 (every 0.1 s) timesteps, so that every particle which is in an certain area will get changed his temperature.
Usually im running this program for about 1 s.
But yesterday, i discovered, that there is no temperature exchange, between the two particle, at all.
My previsios error was caused, because I use the restart-function.
I hope you can help me.
Best regards
RobertG
RobertG | Mon, 03/30/2015 - 11:45
I fixed it.
Okey, that was an annoying bug.
Basically, it was caused, because I have use the fix heat/gran command for just one particle type.
This command, initialize the temperature and!!!! says which particle types should be accounted for calculations.
I have used it just!!! for initialize the termperature for one!!!! particle type and it was calculated for one particle-type.
I whould like to thank every one, who tried to help me with this problem.
Best regards
Robert