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IDProjectCategoryView StatusDate SubmittedLast Update
0000990OpenFOAMBugpublic2013-09-04 12:082013-09-05 18:19
Reporterdkxls Assigned Touser2 
PriorityurgentSeveritymajorReproducibilityalways
Status resolvedResolutionfixed 
PlatformLinux x86_64OSopenSUSEOS Version12.2
Summary0000990: [ReitzKHRT]: Wrong droplet diameter after breakup due to incorrect RT-breakup implementation
DescriptionThe droplet diameter in the ReitzKHRT model is incorrectly predicted, because the droplets are broken up as soon as tc > 0 or lambdaRT < d.

Droplets should only be broken up when tc > tauRT and lambdaRT < d!

The attached patch fixes this.
Additional InformationThis was correctly implemented in the dieselSpray classes:
https://github.com/OpenFOAM/OpenFOAM-2.0.x/blob/master/src/lagrangian/dieselSpray/spraySubModels/breakupModel/reitzKHRT/reitzKHRT.C#L138
Tagsbreakup, spray

Activities

dkxls

2013-09-04 12:08

reporter  

0001-RT-breakup-only-if-tc-tauRT.patch (901 bytes)    
From 9f822087f37e7b7fd48c5e4063298b2be8dd4656 Mon Sep 17 00:00:00 2001
From: Armin Wehrfritz <armin.wehrfritz@aalto.fi>
Date: Wed, 4 Sep 2013 13:59:52 +0300
Subject: [PATCH] RT breakup only if tc > tauRT

---
 src/lagrangian/spray/submodels/BreakupModel/ReitzKHRT/ReitzKHRT.C |    2 --
 1 file changed, 2 deletions(-)

diff --git a/src/lagrangian/spray/submodels/BreakupModel/ReitzKHRT/ReitzKHRT.C b/src/lagrangian/spray/submodels/BreakupModel/ReitzKHRT/ReitzKHRT.C
index e714db2..7cea479 100644
--- a/src/lagrangian/spray/submodels/BreakupModel/ReitzKHRT/ReitzKHRT.C
+++ b/src/lagrangian/spray/submodels/BreakupModel/ReitzKHRT/ReitzKHRT.C
@@ -165,8 +165,6 @@ bool Foam::ReitzKHRT<CloudType>::update
     if ((tc > 0) || (lambdaRT < d) )
     {
         tc += dt;
-        scalar multiplier = d/lambdaRT;
-        d = cbrt(d3/multiplier);
     }
 
     // characteristic RT breakup time
-- 
1.7.10.4
0001-RT-breakup-only-if-tc-tauRT.patch (901 bytes)   

wyldckat

2013-09-04 12:19

updater   ~0002457

I was just browsing by and I'm not very familiar with this part of the code. But I think the patch is missing something. Shouldn't this line:

    if ((tc > 0) || (lambdaRT < d) )

be something like this?

    if ((tc > tauRT) || (lambdaRT < d) )

dkxls

2013-09-04 12:27

reporter   ~0002458

The patch only removes two lines, hence no if statement is changed.

The two if statements you mentioned are both necessary and are still in the source code. The patch is correct, in my opinion.

dkxls

2013-09-04 12:28

reporter   ~0002459

But thanks for checking anyways. I very much appreciate any feedback or testing. :)

user2

2013-09-05 18:19

  ~0002468

Thanks for the report - fixed by commit fe729cd

Issue History

Date Modified Username Field Change
2013-09-04 12:08 dkxls New Issue
2013-09-04 12:08 dkxls File Added: 0001-RT-breakup-only-if-tc-tauRT.patch
2013-09-04 12:19 dkxls Tag Attached: spray
2013-09-04 12:19 dkxls Tag Attached: breakup
2013-09-04 12:19 wyldckat Note Added: 0002457
2013-09-04 12:27 dkxls Note Added: 0002458
2013-09-04 12:28 dkxls Note Added: 0002459
2013-09-05 18:19 user2 Note Added: 0002468
2013-09-05 18:19 user2 Status new => resolved
2013-09-05 18:19 user2 Fixed in Version => 2.2.x
2013-09-05 18:19 user2 Resolution open => fixed
2013-09-05 18:19 user2 Assigned To => user2