[amrrhm]

Hi,

I understand that using udf we can do loops on nodes and etc. Is there any way to loop only on nodes in a section (e.g. xy plane) or couple of nodes and export data (velocity, pressure, temperature, ...) for only those points.

Thanks

[MFGT]

Hi amrrhm,

as far as I know, you can evaluate these values with cutplanes via EnSight only.

However, it would be cool if UDF Monitor Point function would work in a similar way like embedding (sphere, box, plane, boundary, ...whatever) and directly receive averaged values for the defined volumens/surfaces, without extra compiling the .dll file. And adding extra variables via a tab.

[amrrhm]

Hi MFGT,

It would be really time saving if we can get variables for just a number of selected nodes.

[alemoine]

Hello all,

If you are interested in only a couple of points throughout the computational domain then you can define UDF Monitor Points. The UDF Monitor Points allow you to set an (x,y,z) location as well as a radius.

If the radius is set to 0.0, CONVERGE will output the nearest cell-center information.

If the radius is greater than 0.0, CONVERGE will average over all of the cell-centers located within the sphere that is defined by the radius and (x,y,z) location.

If you are interested in looking at averaged information on a plane or any non-spherical shape, then as previously mentioned you will need to use Ensight.

Thank you,

[amrrhm]

Thanks alemoine,

Is just defining points in UDF Monitor Points is enough or I have to tell Converge to output the information for those points (e.g. in user_post.c). If the second case is true, how should I do that? I see the coordinates of the points at the end of the udf.in, but is there a function to get the cell number for those coordinates.

It would be very appreciated if you would give more details on this.

Thanks

[MFGT]

Originally Posted by amrrhm

Thanks alemoine,

Is just defining points in UDF Monitor Points is enough or I have to tell Converge to output the information for those points (e.g. in user_post.c). If the second case is true, how should I do that? I see the coordinates of the points at the end of the udf.in, but is there a function to get the cell number for those coordinates.

It would be very appreciated if you would give more details on this.

Thanks

Have a look in the UDF Manual.
After including the UDF monitor points in the case setup, you have to compile a converge.dll and use the converge-udf executable instead of the normal one. If you dont want to add further variables, there is no need for modification of the original .c files (you get them from the converge download area). However, it might be more efficient to delete all unnecessary functions from the makefile and create a smaller converge.dll file.

Adding further variables of interest is not so easy to do, if you dont have a bit of programming background.

[amrrhm]

There is no udf executable for 2.3, is that right or I am missing it?

[ywang89]

Originally Posted by amrrhm

There is no udf executable for 2.3, is that right or I am missing it?

For Linux, there is only one CONVERGE 2.3 executable for the runs with UDFs and without UDFs. When udf_flag=1, the code will try to find the UDF library.

Thanks,

[amrrhm]

Hi all and thank you all for your input.

I have selected couple of points to get output (velocity, temp, pressure) for only those points. I have followed the UDF manual, copied everything in a udf_dir folder, edited the object part in makefile so it only contains user_points.o and user_points_data.o and ran the make. I set the LD_LIBRARY_PATH as "export LD_LIBRARY_PATH=./udf_dir/"

After all, when I try check_inputs in the serial mode I get:

Loading CONVERGE UDF LIBRARY: libconverge_udf.so
./udf_dir/libconverge_udf.so: undefined symbol: user_load_csi_libraries

and if I use the mpi, I get:
error while loading shared libraries: libmpi.so.1: cannot open shared object file: No such file or directory


Any ideas where I am making mistake? Thanks

[alemoine]

Originally Posted by amrrhm

Hi all and thank you all for your input.

I have selected couple of points to get output (velocity, temp, pressure) for only those points. I have followed the UDF manual, copied everything in a udf_dir folder, edited the object part in makefile so it only contains user_points.o and user_points_data.o and ran the make. I set the LD_LIBRARY_PATH as "export LD_LIBRARY_PATH=./udf_dir/"

After all, when I try check_inputs in the serial mode I get:

Loading CONVERGE UDF LIBRARY: libconverge_udf.so
./udf_dir/libconverge_udf.so: undefined symbol: user_load_csi_libraries

and if I use the mpi, I get:
error while loading shared libraries: libmpi.so.1: cannot open shared object file: No such file or directory


Any ideas where I am making mistake? Thanks

Hi amrrhm,

If you are using CONVERGE v2.3, you will need to include the user_dynamic_routines.c in the directory. Therefore, your makefile should have the following object files:

OBJS = user_dynamic_routines.o\
user_points.o\
user_points_data.o

Please change the makefile and rerun make to see if this error message goes away.

It should be noted that ALL udf's in v2.3 require user_dynamic_routines.c.

Thank you,

[amrrhm]

It works now. Thank you very much.