Search found 22 matches
- Fri Mar 11, 2016 6:44 pm
- Forum: Users
- Topic: Discontinuity Factor Calculation
- Replies: 5
- Views: 3405
Re: Discontinuity Factor Calculation
Jaakko, I believe that would be helpful. What we're really after are the heterogeneous currents and fluxes on the 6 surfaces of the cube/cuboid. We would be able to produce our own homogeneous solutions for non-reflective boundary conditions. So as long as the heterogeneous currents and surface flux...
- Thu Mar 10, 2016 7:18 pm
- Forum: Users
- Topic: Discontinuity Factor Calculation
- Replies: 5
- Views: 3405
Re: Discontinuity Factor Calculation
Jaakko, Ok, thank you for confirming the surface is super-imposed over the geometry. This is what I thought. And yes, I did receive warnings about negative values in the homogeneous flux solution. There are other regions where the values do match, it just happened that this region did not. I'm assum...
- Thu Mar 10, 2016 1:40 am
- Forum: Users
- Topic: Discontinuity Factor Calculation
- Replies: 5
- Views: 3405
Discontinuity Factor Calculation
Hello, I've been experimenting with the "set adf" capabilities in Serpent2. I was attempting to extract ADFs from a 3x3 assembly problem and noticed that the discontinuity factor calculated in Serpent is not equal to the ratio of the heterogeneous surface flux to the homogeneous surface flux printed...
- Mon Aug 31, 2015 9:45 pm
- Forum: Methods
- Topic: Detectors and Delta Tracking
- Replies: 8
- Views: 13156
Re: Detectors and Delta Tracking
I added "return 0.0" at the beginning of stopatboundary.c as you suggested. Here are the results: Original executable: Coarse mesh eigenvalue: 1.04082 +- 0.00032 Fine mesh eigenvalue: 1.04041 +- 0.00034 Modified executable (return 0.0): Coarse mesh eigenvalue: 1.04163 +- 0.00023 Fine mesh eigenvalue...
- Mon Aug 24, 2015 8:22 pm
- Forum: Methods
- Topic: Detectors and Delta Tracking
- Replies: 8
- Views: 13156
Re: Detectors and Delta Tracking
Jaakko, Thanks for the quick reply. This was good information to know. However, I don't believe this is what was causing the difference as both my cases were either using detectors or not. We went back and performed a few additional calculations and this is what we found: -With Serpent2, both the fi...
- Thu Aug 20, 2015 12:11 am
- Forum: Methods
- Topic: Detectors and Delta Tracking
- Replies: 8
- Views: 13156
Re: Detectors and Delta Tracking
I have a follow up question on this topic. By adding the set dt 1 card to a small 2 region problem, I was able to produce the same eigenvalue with a coarse mesh and a fine mesh (same overall global geometry). However, when I perform the same steps for a larger assembly problem, there is about a 10pc...
- Wed Jul 29, 2015 9:31 pm
- Forum: Methods
- Topic: Detectors and Delta Tracking
- Replies: 8
- Views: 13156
Re: Detectors and Delta Tracking
I added the set dt 1 card to my inputs and they now produce the same eigenvalue. Looks like my input was switching to surface tracking. Thanks for the help!
- Tue Jul 28, 2015 11:41 pm
- Forum: Methods
- Topic: Detectors and Delta Tracking
- Replies: 8
- Views: 13156
Detectors and Delta Tracking
I have a simple question that I think will explain something I'm seeing. If you add a surface detector to a problem geometry, does Serpent stop any neutron that crosses the surface and resample for the other side when using delta tracking? I've noticed that when I refine my mesh (use more gcus and m...
- Sun Dec 21, 2014 10:12 pm
- Forum: Bug reports
- Topic: Unexpected up-scatter XS larger than down-scatter XS
- Replies: 4
- Views: 5461
Re: Unexpected up-scatter XS larger than down-scatter XS
Hi Tuomas and Jaakko, So I checked the reaction rates for the up-scatter and down-scatter: Up-scatter: RR = 3.98263E-02*2.90579E-03 = 1.15727E-04 Down-scatter: RR = 4.46476E+01*4.99760E-04 = 2.23131E-02 In this instance you are right that the reaction rate for down-scatter is higher. However, I also...
- Mon Dec 08, 2014 10:03 pm
- Forum: Bug reports
- Topic: Unexpected up-scatter XS larger than down-scatter XS
- Replies: 4
- Views: 5461
Unexpected up-scatter XS larger than down-scatter XS
Hi all, I was running a simple 2 region pin cell problem in Serpent 1.1.19 and discovered that for one of the regions, the up-scatter cross section (2->1) is larger than the down-scatter cross section (1->2). The two regions are stacked on top of each other and I used 2 energy groups with the cutoff...