Frequently Asked Questions

Q: What does a Finite Element software package such as NM-SESES do ?
Typical design and optimization problems that scientists and engineers encounter are most often expressed by formulating the governing laws, namely constitutive and balance laws. The resulting equations belong, almost exclusively, to the class of partial differential equations and in general they couple together different physical quantities. In light of the specific geometries and conditions set upon the boundaries of realistic domains as well as the complexity of many material laws, analytical solutions to these equations can rarely be found, thus motivating the use of numerical tools such as NM-SESES. NM-SESES is based on the Finite Element Method, which is one of the most powerful and widely adopted methods for modeling and analysis of complex physical and chemical systems and processes.

Q: How do I interact with NM-SESES ?
NM-SESES comes with a graphical Front-End program consisting of an editor, a 2D mesh generator and a viewing engine for displaying geometries and numerical results. In addition, NM-SESES provides a very powerful functional input language for the specification of geometries, physical models, boundary conditions and numerical solution methods. The input file follows a well-defined and documented syntax similar to common high-level programming languages. Together with colored syntax highlighting and practical error handling, this interaction mode enables a high-level control over the simulation to be carried out and simple multiphysics problems are defined within minutes.

Q: Where can I find NM-SESES documentation and examples ?
NM-SESES comes with a user pdf-manual and a pdf-tutorial with many practical examples. In addition, many other running examples can be found in the (example) directory of the distribution.

Q: What about mesh generation in NM-SESES ?
NM-SESES does not create meshes for you by directly importing data from CAD systems. For a 2D geometry, you can use the graphical and practical mesh builder inside the Front-End program. For a 3D geometry, the method of choice is to use the functional input language to algebraically construct the mesh. An alternative is to import an externally built mesh based on rectangular and hexahedral elements. An initial mesh can be adaptively refined by NM-SESES.

Q: How does NM-SESES interact with other software ?
On the one hand, NM-SESES can be called in batch mode from any other programs without using the graphical Front-End program. On the other hand, NM-SESES can call another program.

Q: How can NM-SESES simulation results be exported ?
The computed fields are stored in a NM-SESES data file to be viewed in the Front-End program. In addition, several options are available for exporting numerical fields in a user-defined format at user-defined mesh locations as well as to integrate them on a user-defined domain.

Q: The license file is installed in the NMSeses/bin directory, but the message "No License File found" appears.

A: The message error tells you exactly what license file NM-SESES is looking for.

Q: The graphical Front-End shows no field distribution or the atual one seems to be completely inexact. What is wrong ?
You probably changed the ME-Mesh and there is an inconsistency of the actual mesh and the computed numerical data. In this case you have to redo the simulation by pressing the Run-Button. Another possibility may be frozen min/max values enabled for a previous field distribution which may let look the actual field as constant.

Q: The Front-End works and shows the model. After pressing the run-button, a console window shows up and disappears immediately thereafter. What is wrong ?
The kernel quickly finished probably due to a numerical exception and the option (-w) was not used. Use this option to let the Kernel wait a user response before terminating.

Q: I get the error message "SESES HARD ERROR: Numerical math-lib error". What does this message mean ?
This is the result of an illegal mathematical operation within the simulation. For example a division by zero or the logarithm of a negative value.

Q: When I use the "Write AtStep" or "Dump AtStep" statements, only the last statement actually produces an output. What is wrong ?
Only one "AtStep" statement can be active, which is the last one defined. However, you can easily define a number of different outputs within one single statement.

Q: I have found a bug in the program. Where can I report it?
A: Please send an email to