View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0004023 | OpenFOAM | Bug | public | 2023-10-14 16:33 | 2023-10-17 09:02 |
| Reporter | Karam92 | Assigned To | will | ||
| Priority | high | Severity | major | Reproducibility | always |
| Status | closed | Resolution | no change required | ||
| Product Version | 11 | ||||
| Summary | 0004023: NCC fetal invalide conservation in Interface | ||||
| Description | As I attempted to run a simulation for a turbomachinery system with NCC using OpenFOAM version 11, I discovered that while the simulation accurately conserves mass between the inlet and outlet, there were illogical values at the interface. Additionally, the inflow rate for the incompressible fluid in interface was found to be invalid and significantly deviated from the expected real values | ||||
| Steps To Reproduce | The most effective way to reproduce the problem is to run the "nonConformalChannel" tutorial and measure the value of the "nonCoupleUp" patch using the #includeFunc patchFlowRate(patch=nonCoupleUp) directive in the controlDict file. Then, compare this value with the inflow rate. | ||||
| Additional Information | I attempted to rerun the simulation with OpenFOAM 10 using cyclicAMI, and the inflow rate value is physically accurate and conservatively modeled | ||||
| Tags | No tags attached. | ||||
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You misunderstand how this works. The "nonCoupleUp" patch is the wall. It is not coupled. Hence the name; "nonCouple...". This condition applies to whatever area is left over after the intersection engine has connected everything it can. In the old terminology, this is the ACMI-non-overlap patch. In this case, the intersection is basically 100%, so the "nonCoupleUp" patch gets removed entirely. The patch you should be monitoring is "nonConformalCyclic_on_nonCoupleUp". I.e., "#includeFunc patchFlowRate(patch=nonConformalCyclic_on_nonCoupleUp)". The AMI simulation of the nonConformalChannel is not conservative, either between the inlet and outlet, or across the interface. The graph generated by the Allrun script demonstrates this unambiguously. AMI will look conservative if you compare the inlet with the upstream interface (coupleUp), but that's because the flow hasn't crossed the AMI between these two patches. If you compare the inlet with the outlet or the downstream interface (coupleDown) you will see the non-conservation. The NCC simulation, by contrast, is conservative to within the solve tolerance of the pressure equation wherever you measure it. https://cfd.direct/openfoam/free-software/non-conformal-coupling/ https://cfd.direct/openfoam/free-software/using-non-conformal-coupling/ Closing. User support. |
