12 Replies Latest reply on Jun 2, 2014 11:23 PM by Jared Conway

    Thermal analysis execution problem

    Allan Douglas Santos Silva

      Hi There.

      I'm trying to perform a transciente analysis in a system with concentric cylinders and with a heat power at the center of the system. But the software could never finish the analysis; always appears an issue, like the error mensage: Status code 9999 PCGLS_FATAL. Or something like: the Diagonal coefficient matrix is zero.And further something like: the results not converged after 1000 iterations.


      Beyond that the analysis  take too long time. The program takes sometimes 24 hours to calculate the view factor and after he spends hours to make one iteraction. It happens that at the interactions the solidworks fails to converge the results; most of the time he could not even pass the first iteration.


      This is analysis are par of a  research project; it is very important realize them in the next weeks. If anyone can help, I would greatly appreciate it.

      Above is the link of a zip archive of all the parts of the model. There are several   simulations in the model, from the more simplified model to the more complete.At the zip archive are atached also the curve of ambient temperature and heat power, beyond of specific heat of Aluminium.





      From already thank you

      PS: I'm Brazilin, so sorry for my english.

        • Re: Thermal analysis execution problem
          Allan Douglas Santos Silva

          I inserted the link because he is too many bigger to attached it.The properties of studies are already set; only just run them. I'm new in simulations like this, therefore i think that i make some mistake tha i can't figure out.

          • Re: Thermal analysis execution problem
            Allan Douglas Santos Silva

            If someone solve this problem, we will not have problem in including your name as contributor on our next paper

              • Re: Thermal analysis execution problem
                Jared Conway

                Can you give a synopsis of the analysis?


                How does heat go in?

                How does it go out?

                What do you want to learn?

                What are you expecting?


                My recommendation would to start really small and simple. Make sure it works and you understand the program. Them build up to the full analysis.


                The error looks similar to something I've run into before where there was no way for heat to leave the system.

                  • Re: Thermal analysis execution problem
                    Allan Douglas Santos Silva

                    Off Course!


                    The system consists in five concentric cylindrical shells, with a heat power at the central position . All the system is in the vacuum, thus the heat exchange happens only for radiation between the cylinders and by the heat radiated by the heat power.So the heat power radiates the heat for the most internal cylinder, and this cylinder radiates heat for the next cylinder and so on, until the external cylinder that radiates the heat for the environment.

                    It's a transient analysis and we want to find out how will be the temperature distribution at the cylinders. We already have the experimental results and we need to reproduce this results through the thermal analysis from SW. The problem is that  the analysis don't work.


                    I'm sure that I'm making some mistake, but I don't know what is it.I tried a  very simple case, with only one cylinder and the heat power at the center;nevertheless the analysis take more of two days and after all this time the solver fails, with a message saying that the results not converged after 1000 iterations.


                    What do you think?