resistance between two points
Hello,
first of all, I would like to thank all the developers for sfepy and related tools, which is absolutely awsome, mainly because of the great flexibility.
I am afraid I have a very basic problem which everyone knows how to solve except of me. I have two points (nodes) and I want to calculate heat resistance between them. By heat resistance I mean ratio of temperature difference and heat power, so the unit will be Kelvin per watt, K/W. I think there are two possible ways:
One node has defined temperature. The other node has defined power. Then I find temperature of the other node. But - how to assign power in watts? I wanted to get inspired by the example poisson_functions.py, but the "load" parameter is power density (in watts per cubic meter). Therefore, in one node there is infinite power density.
Both nodes have defined temperature. Now I need to calculate the total flux over surface surrounding any of the nodes. But how?
Please, could you give me an advice, which of these two ways should I use and what examples from the documentation is the closest to my problem?
Thank you very much, Jan Martinek
Hello Jan,
On 09/06/2012 04:38 PM, jmartinek wrote:
Hello,
first of all, I would like to thank all the developers for sfepy and related tools, which is absolutely awsome, mainly because of the great flexibility.
Thanks, glad to hear that!
I am afraid I have a very basic problem which everyone knows how to solve except of me. I have two points (nodes) and I want to calculate heat resistance between them. By heat resistance I mean ratio of temperature difference and heat power, so the unit will be Kelvin per watt, K/W. I think there are two possible ways:
So you are solving a problem with Laplacian operator, right? What is the definition heat of heat power? To see the exact equations would help :). I will try to answer anyway below.
- One node has defined temperature. The other node has defined power. Then I find temperature of the other node. But - how to assign power in watts? I wanted to get inspired by the example poisson_functions.py, but the "load" parameter is power density (in watts per cubic meter). Therefore, in one node there is infinite power density.
Could you define the load over a small element surface instead? Then knowing the face area, it would be easy to impose the correct power density.
- Both nodes have defined temperature. Now I need to calculate the total flux over surface surrounding any of the nodes. But how?
We were talking about fluxes in recent threads with David Libault and Alec Kalinin ("Evaluate a solution in the arbitrary point in the domain"), maybe you could find something useful there.
Best regards, r. [1] https://groups.google.com/forum/?fromgroups=#!topic/sfepy-devel/xfzjsLSRHvM
Please, could you give me an advice, which of these two ways should I use and what examples from the documentation is the closest to my problem?
Thank you very much, Jan Martinek
participants (2)
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jmartinek
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Robert Cimrman