Hi Jan, On line 5912, velocity BC is written with capital letter V instead of small letter v (as in 5928). If you write velocity with small letter, it'll read the BC in the .usr file (userbc subroutine), otherwise you have to specify the values of velocity in the .rea file. In addition, in the elements (E) BC you have to specify E n1 n2 n3 n4 0 0 0 n1: Number of element n2: side of element n3: element connected n4: side of the element connected. However, you've set n3 and n4 to 0. I hope it helps you. Regards, SL El 01-07-2014 13:56, [email protected] escribió:
Hello Neks, I' trying to solve the MHD equations and encounter the same error reported here: http://lists.mcs.anl.gov/pipermail/nek5000-users/2011-June/001365.html. For testing, I have set up a small grid (384 elements) with B=0 at the boundaries and B=0 as initial conditions, and the error appears before the first timestep. As mentioned in the documentation, I have used the same BC-types for the B Field as for the velocity, so in the .rea file it reads:
5909 ***** PASSIVE SCALAR 1 BOUNDARY CONDITIONS ***** 5910 E 1 1 0.00000 0.00000 0.00000 0.00000 0.00000 5911 E 1 2 0.00000 0.00000 0.00000 0.00000 0.00000 5912 V 1 3 0.00000 0.00000 0.00000 0.00000 0.00000 5913 E 1 4 0.00000 0.00000 0.00000 0.00000 0.00000 5914 E 1 5 0.00000 0.00000 0.00000 0.00000 0.00000 5915 E 1 6 0.00000 0.00000 0.00000 0.00000 0.00000 5916 E 2 1 0.00000 0.00000 0.00000 0.00000 0.00000 5917 E 2 2 0.00000 0.00000 0.00000 0.00000 0.00000 5918 E 2 3 0.00000 0.00000 0.00000 0.00000 0.00000 5919 E 2 4 0.00000 0.00000 0.00000 0.00000 0.00000 5920 E 2 5 0.00000 0.00000 0.00000 0.00000 0.00000 5921 E 2 6 0.00000 0.00000 0.00000 0.00000 0.00000 5922 E 3 1 0.00000 0.00000 0.00000 0.00000 0.00000 5923 E 3 2 0.00000 0.00000 0.00000 0.00000 0.00000 5924 E 3 3 0.00000 0.00000 0.00000 0.00000 0.00000 5925 E 3 4 0.00000 0.00000 0.00000 0.00000 0.00000 5926 E 3 5 0.00000 0.00000 0.00000 0.00000 0.00000 5927 E 3 6 0.00000 0.00000 0.00000 0.00000 0.00000 5928 v 4 1 0.00000 0.00000 0.00000 0.00000 0.00000 5929 E 4 2 0.00000 0.00000 0.00000 0.00000 0.00000 5930 E 4 3 0.00000 0.00000 0.00000 0.00000 0.00000 etc.
The thread above mentioned that it was due to incorrect BCs, but unfortunately no more details were given.
Cheers, Jan
_______________________________________________ Nek5000-users mailing list [email protected] https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users