With that statement, I used to begin my day in the blue building of PVcomb… I had the chance to participate with the PV to Fuels Technology group in a project for developing a novel type of hydrogen electrolyzers. These electrolyzers are devices that can use the produced voltage from solar cells to split water molecules into hydrogen and oxygen. Therefore, they can enable us to store the solar energy as a chemical fuel, H2; so that we can use it later whenever there is a demand for electricity regardless of the solar irradiance profile over the day.
My work is all about simulating new structures and parameters for the H2 electrolyzers using COMSOL Multiphysics. The capabilities of this program for simulating physical phenomena are astonishing. However, seeking the desired results is obstructed with many problems, and figuring the big picture requires analyzing all the results together.
Many lessons were learned from these simulations, not only about the fluid mechanics and the electrochemistry happening in the electrolyzer but also about the simulation as a process in itself. Usually, I leave two simulations for the workstation to calculate them overnight. In my first days in the internship, I always had that statement in the morning with the results: “very ill-conditioned preconditioner”. It took some time to figure out what it really means and how to be solved but it never stops visiting me to the extent that it became my favorite error now.
But wait! It is not the happy ending yet: I have more warning statements, and ambiguous results to interpret. I wish to find my way to the desired electrolyzer by the end of my internship. To conclude, I would say: behind every error, there is a story to tell.
Alaaeldin Elozeiri
Thank you for sharing your struggles with us and again, I like the way you are writing. The error statement “very ill-conditioned preconditioner” sounds funny to me. I do not have anything to do with simulations etc, but what does that error statement mean? Couldn’t the program handle the parameters or the values/input you gave ?
That’s so nice to hear
Simulation is about gaining knowledge of the physical phenomena happening through solving some fundamental equations. As real applications are so complex to be analyzed analytically, the structure is divided into very small sections/domains and software solve the fundamental equations numerically in each section with the aid of the defined boundaries and initial conditions.
The mentioned error tells that the software failed to find a solution with the defined domains, boundaries and initial conditions. So, I need to enhance how the structure is segmented and the initial condition to find a correct solution.
I really love it. Patient analysis of what has gone wrong is THE crucial part of science. Keep on improving the programme and we are eagerly awaiting your talk or your poster at the final presentation!
Thanks, ARÖ
Dear Alaaeldin Elozeiri, I am a kind of geek of the simulations. In my degree, I tend to work with Matlab and Ansys. I was wondering what module are you using.
Best regards, Julio Guzmán.
it is nice to find friends with similar interests ^^
my problem requires to use two physics modules at least: one for the fluid flow and another for the electrochemistry study.
This is another very interesting post from you. But I was wondering: what are typical parameters in these simulations?
I really hope you find the right electrolyzer within the next four weeks. Good luck!
Thanks, Max
Each structure can be optimized mainly for its hydrogen production by controlling its geometric and operational parameters like the dimensions of the electrolyzer and its periodicity.