Meco

You know that bang in the pipes when someone shuts a tap fast? That's not the tap. That's the water refusing to stop. Its momentum has nowhere to go, so it piles up into a pressure wave and runs back up the pipe.

Meco 0.7: the Merlin 1D in Mission 13 finally has its pintle. Also: • The Injector Head: coaxial or pintle, built in 3D while you type • Six missions skip the plumbing chores • Medals. Miss gold and the debrief tells you why. Hit gold and it shuts up.

A valve snaps nearly shut on a moving LOX line. In Meco's Mission 4, the pressure jumps from about 2.5 to about 26 bar, then rings. For a moment the LOX runs backwards. That's water hammer, on the line you built in Mission 2. Stopping it is your problem.

In a space game, the engine is a part you pick. In Meco, you design it, with real physics. Wire pumps, injectors and nozzles on a node graph, press Run Test, and the live graphs answer. Design. Test. Fail. Learn.

I wrote a tooltip for Meco, my rocket engine design sim, that argued with one of my own missions. My first draft said raising back pressure cuts feed flow. That is only true while the line is subsonic. Once the nozzle chokes, flow is set upstream and stops answering to it.

Heads-up if you have a saved engine from Meco 0.5: in 0.6, pumps make roughly 9 to 13% less head and torque than they did. An engine that used to close may need a retune. If it suddenly runs lean, the pumps are where to look first.

Push a bell too far at sea level in Meco 0.6 and you can watch the flow let go of the wall. The flow field renders as a 3D volume inside your bell. Past the separation point the field grays out, and thrust only counts where the flow is still pushing.

Meco 0.6 is out. Four numbers. A real engine bell. And you can see it now. The chamber, the cooling, the flow field. Live in 3D. Load the Merlin 1D template. Make it yours.

Miku, your mentor at Mecodyne, leaves a note: do not press Run Test. You press Run Test. A real engine spins up, the graphs start moving, and that is your first day on the job.

Meco 0.5 ships with a new first day on the job. Miku leaves a note: don't press Run Test, I'm in a meeting. You press Run Test anyway. A real Vulcain engine spins up on your screen. So much for the note.