Dannie here. I build software to help you learn about rocket engine design interactively. Want more after Kerbal? Follow my journey!
London
Joined October 2021
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Four numbers. Four hundred cooling channels you never had to draw. Go ahead, spin the camera.
Then every valve on a schedule, staged in time. Get the sequence right and the engine runs nominal.
Meco. Design. Test. Fail. Learn.
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.
In 1898, the man who later gave aviation its lift theorem worked out how slowly you have to close a valve to stay safe.
In Meco, Mission 4 hands you that valve and lets you slam it. On liquid oxygen. store.steampowered.com/app/1…
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.
Still playing? Mission 12:
• coaxial head, LOX and liquid hydrogen
• tune each leg's pressure drop to 10 to 30% of chamber pressure
• too soft and chamber swings move the flow (chugging), too stiff and you pay pump power for nothing
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.
Meco is a rocket engine design sim with real physics, in Early Access on Steam: store.steampowered.com/app/1…
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.
Mission 12 teaches it on a LOX and liquid-hydrogen engine. Size each leg so its pressure drop lands at 10 to 30% of chamber pressure: stiff enough that a swing in the chamber barely moves the flow, soft enough that you aren't wasting pump power.
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.
On the bench right now: the injector head, promoted to a full assembly. The head renders in 3D like the Thrust Chamber and Turbopump already do, and it rebuilds as you type, each time a field holds a number it can build from. Running here only, not in anything you can download.
