I am using Elmer7 rev 6064 for Windows from Sourceforge
I have found that once the Model Boundary Conditions input has been entered and updated, using the Remove function for Boundary Conditions works erratically. The first time Remove is invoked it usually successfully removes the condition and the tagged entities. On the second and subsequent attempts to invoke remove for other Boundary Conditions, the update does not take place. The window does not close. I have not tested this problem on Model section input other than Boundary Condition, but suspect that the problem is common to all Model entry windows.
There is a work around. If the Boundary Condition is not removed, but all of the entities to which it is applied are un-checked, then it is equivalent to removing the Boundary Condition. A new Boundary Condition can be created and the old entities applied to it without problem. When performing thermal analysis involving radiation and conduction it is useful to solve the combined problem, then remove the radiation boundary conditions to see how much of the heat transfer comes from conduction alone. Thus the need to remove Boundary Conditions easily.
I would add two items, which are not strictly bugs, but which should be included in any new documentation, or disclosed in a forum that is likely to get attention:
1. When materials properties are defined under Materials, and emissivity is given, subsequent definitions of emissivity under radiation boundary conditions assigned to specific boundaries are ignored. In order for the boundary conditions at those boundaries to apply, the emissivity in the materials section must be removed. Since materials properties are often picked from a library, the user may not even know that emissivity has been entered.
2. If , in the GUI, an attempt is made to fix the temperature of a Body, rather than a Boundary by using the Body Force section, the input must be made with syntax that is different from most other data entry in the GUI. Failure to put the control words REAL before the temperature and the temperature condition will cause the generated .Sif file to fail to execute. This may sound like a small issue, but I believe that it relates to a number of earlier posts about the difference between temperatures on a Boundary and temperatures of a Body. I believe that the question was really, "Why doesn't the application of temperatures to Bodies work". This problem comes up especially in thermal radiation problems where a Boundary has already had a radiation condition applied to it. That boundary is no longer selectable to apply a temperature. However the Body to which it is associated is still a check-able option. I do not know if ELMER allows multiple conditions to be applied to a Boundary, but the GUI does not make it a check-able option.