I would also recommend checking out salome. It has a parametric CAD module like you would be used to in SolidWorks. It felt a little less finicky to me than freecad , and I also think it has more controllable STL generation compared to freecad.

I think sometime went wrong with your KDE frameworks description. Looks like the some python notes got in there instead.

Love seeing all the updates! OpenSUSE has been working great for me.

One more thing. Running hydrogen, even in blends of 30% hydrogen/70% natural gas, creates a large amount of extra NOx production. NOx, of course, is a pretty nasty pollutant. We need to redesign our current natural gas burners to help control NOx at high hydrogen blends.

Also, I think we need to be moving towards 100% hydrogen if we want to use combustion as a green replacement for natural gas. However, I don’t think many of the appliances that currently use natural gas could safely use 100% hydrogen because of the properties of hydrogen gas. Primarily, I think the flame speed of hydrogen would require us to redesign the various combustors that use natural gas currently so that we don’t have flashbacks. Additionally, the hotter burning of hydrogen might cause material failure issues in our current natural gas burners. The research I’ve done is shown that we could probably get away with 30 to 40% hydrogen, maybe dependent on the exact burner. I don’t think moving to 100% hydrogen is feasible without a massive replacement of all of our gas burning appliances.

Oh neat, I actually know a lot about hydrogen-natural gas blends!

I read the report because of this claim:

And now, a team of British researchers has found adding hydrogen to natural gas actually increases how much natural gas leaks from stove burners and boilers because the smaller hydrogen molecules help the larger methane ones escape.

I’ve never heard of small hydrogen molecules helping larger molecules leak. I was curious what the mechanism for this was. It turns out the report does not make that claim at all. In fact, the report claims the additional leakage from hydrogen blends is most likely just the hydrogen leaking. I didn’t run the numbers myself but the data presented seems approximately aligned with that. Hydrogen leaking through fittings is already a well-known and established challenge of blending hydrogen with natural gas. So the central thesis of this news article is completely fabricated.

I am a little surprised the utility companies are going to soon be mixing in hydrogen. I didn’t think we we’re quite ready to blend in hydrogen into natural gas for the leakage reason, and also because of production scaling issues that we haven’t resolved yet. These challenges are likely within reach soon. For example, the United States department of energy has a large research initiative right now to help lower the cost of hydrogen production to be more competitive with natural gas. We also need to make sure that hydrogen is produced in a carbon-free or carbon neutral way, which is probably going to be dependent upon our electrical grid becoming carbon free.

I’ve been using SALOME to create parametric 3D geometry. My use case is to parameterize my geometry features and export to STL files that I use with OpenFOAM. SALOME is integrated with a couple of grid generators, and I really like it’s 2D/triangulation/STL integration with netgen. You can specify faces for refinement to a desired mesh size, so for example around complex features you can create a fine STL mesh and on simple shapes you can have a really coarse mesh.

I’ve found the 3D modeling to be pretty straightforward, and SALOME usually does a pretty good job if you have to go back and modify previous features (something I’ve struggled with in FreeCAD).

I’ve also used FreeCAD for mesh generation, and it works ok but I’ve found the triangulation leaves a lot to be desired for splitting up the mesh as needed for OpenFOAM boundaries.

If you’re making STL files for 3D printing and you want a parametric CAD modeler for engineering parts, give it a try. If you want complex faces with artistic style, I would suggest Blender.