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Temp. difference in cold flow compression/expansion SprayEngineFoam with layered A/R

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Old   April 29, 2014, 15:26
Default Temp. difference in compression/expansion SprayEngineFoam with layered A/R
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Hello all,

I am currently running a simulation with sprayEngineFoam by using a simple box with layered addition removal as described by Marco in the post "engineMesh with layered addition removal".

First, I would like to mention that there is a bug in the pEqn.H used by sprayEngineFoam. There is a mismatch of unity of measures when operating surfaceScalarField phiHbyA, so line 55 of pEqn.H should be modified as

(fvc::interpolate(rho*HbyA) & mesh.Sf())

At the moment, I am simulating only compression/expansion, starting from -180°CA (BDC) to +180°CA (next BDC).
What I noticed is that temperature and pressure are not specular respect to TDC, e.g. at -50°CA during compression temperature(640K) and pressure are substantially higher than at +50°CA during expansion (T=285K!!).
From theory they should be the same, since neither combustion nor fuel injection occur.

I attach the thermophysicalProperties and fvSolution files.

Has anybody noticed these P and T behaviours with layered A/R and engineMesh motion?
I was wondering if there could be an issue in the meshPhi flux that is not correctly computed expecially when new cells are added during expansion.

Can anybody help me? Thanks a lot!

Attached Files
File Type: txt thermophysicalProperties.txt (1.4 KB, 7 views)
File Type: txt fvSolution.txt (2.5 KB, 6 views)

Last edited by lucasal; May 4, 2014 at 09:24.
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layereda/r, sprayenginefoam, temperature difference

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