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IDProjectCategoryView StatusLast Update
0002650OpenFOAM[All Projects] Bugpublic2017-08-29 14:56
ReporterSahasAssigned Tohenry 
Status closedResolutionsuspended 
Product Versiondev 
Fixed in Version 
Summary0002650: Wrong factors for the cubic inerpolation scheme
DescriptionDetails of the problem and corresponding mathematics can be found in this thread:

To sum, there are the wrong values of kSc, kVecP, kVecN in cubic interpolation (see file src/finiteVolume/interpolation/surfaceInterpolation/schemes/cubic/cubic.H, lines 126, 127 and 142). Now the code is:
const surfaceScalarField kVecP(sqr(scalar(1) - lambda)*lambda);
const surfaceScalarField kVecN(sqr(lambda)*(lambda - scalar(1)));
surfaceInterpolationScheme<Type>::interpolate(vf, kSc, -kSc)

Should be:
const surfaceScalarField kVecN(-sqr(scalar(1) - lambda)*lambda);
const surfaceScalarField kVecP(-sqr(lambda)*(lambda - scalar(1)));
surfaceInterpolationScheme<Type>::interpolate(vf, -kSc, kSc)
TagsNo tags attached.



2017-08-04 16:42

reporter   ~0008514

Present formula gives wrong results only in case of non-uniform grids, of course.


2017-08-04 17:15

manager   ~0008515

Can you provide a simple case which demonstrates the need for this change which can also be used to test the new implementation?


2017-08-04 18:44

reporter   ~0008517

I don't have such case but may be I can come up with it in a few days.
Anyway current implementation is incorrect "per se".


2017-08-04 19:35

manager   ~0008518

The current implementation may incorrect and your suggested change may be correct but this needs to be demonstrated and the new implementation tested otherwise it is a random change which may or may not improve the code.


2017-08-17 14:57

manager   ~0008600

Have you found a case which demonstrates the problem and verifies the proposed correction? If not should I close this report and "not reproducible"?


2017-08-17 17:29

reporter   ~0008602

Hello, Henry! Sorry for delaying with answer.
I have performed some tests and found them unsatisfactory (the difference in results obtained using two formulas is not strong and obvious). Thus you may close the report with reason "suspended", I think. If I find a good test I reopen the report.


2017-08-29 14:56

manager   ~0008645

Suspended pending verification of the proposed change.

Issue History

Date Modified Username Field Change
2017-08-04 16:34 Sahas New Issue
2017-08-04 16:42 Sahas Note Added: 0008514
2017-08-04 17:15 henry Note Added: 0008515
2017-08-04 18:44 Sahas Note Added: 0008517
2017-08-04 19:35 henry Note Added: 0008518
2017-08-17 14:57 henry Note Added: 0008600
2017-08-17 17:29 Sahas Note Added: 0008602
2017-08-29 14:56 henry Assigned To => henry
2017-08-29 14:56 henry Status new => closed
2017-08-29 14:56 henry Resolution open => suspended
2017-08-29 14:56 henry Note Added: 0008645