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Old   April 10, 2019, 08:31
Default Subdomains inside a Domain
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Pedro Oliveira
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I have designed 3 cylinder subdomains inside a conical outdomain. The subdomains it will work as geometry reference for different energy sources(on future work). But first I wanna be sure that the cylidners geometry doenst influence the results. I have subtracted ( on Space Claim) the subdomains to the outdomain and defined on CFX-Pre, the "full domain" as the outdomain( without the cylinders volume) plus the cylinders subdomains.

I have also defined the interface between the various cyliders and also between the cylinders and the outdomain as Conservative Interface Flux for Mass and Momentum and GGI.

The "full domain" on CFX-Pre is full of liquid water, then I distribute 1000W in all the domain equally, trough one total energy source defined for the outdomain plus the cylinders.


After that, I did the same experience but just with the conical outdomain, that is, now I only have the conical outdomain without any cylinders. The water is on the full conical domain and I have define an energy Source of 1000W equally on the conical domain, through the total energy source of1000W.

I noticed that if I defined an energy Total Source of 1000W through the outdomain plus the cylinders, I get different temperature results when compared if I distribute the energy in the conical outdomain( without cylinder geometry subdomains reference).



Does anyone has any clue about this?
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Old   April 10, 2019, 09:27
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Have you looked at the flow summary at the end of the run?

There should be a section for the total amount of energy introduced in each subdomain. Do they add up to your expected value?

Repeat for the single volume simulation, and compare. Are the reported values equal between both simulations?
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Old   April 10, 2019, 14:34
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I have already made a simulation with the single volume simulation, the mean temperature is 550K, but for the case with cylinders, the mean temperature is 460K.

Notice that the energy is 250W (and not 1000W as I said before) and that the energy source is equally dsitributed on the single volume domain and for the cases with the cylinders is equally distributed for the cylinders and outdomain.

I post here the images of the flow summary, where C1, C2 and C3 are the cylinders and Fluido is the outdomain, and the flow sumary of the case for single volume too.

Do you notice anything here that could lead to such a big temperature difference?

(The simulation conditions are exactly the same for both, the only difference is the cylinders geometry inside the outdomain, which shouldnt interfere with temperature or energy distribution)
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Last edited by oliveira1820; April 11, 2019 at 06:10.
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Old   April 11, 2019, 06:11
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