Best rocket engine test we've done so far!

On February 12, 2022 we conducted a 3 second hot-fire test of our prototype rocket engine, Ronald. This is the same combustion chamber we fired twice two weeks prior. We didn't expect it to continue holding up from additional testing, but it actually did quite well. There was a bit of erosion at the throat from prior tests, and that actually caused some fuel leakage from the cooling channels into the chamber. This turned out to be some inadvertent film cooling, and it is helping the nozzle hold up against the heat. Also, our igniter survived this test, whereas it had failed each of the two previous tests. We use an automotive glow plug with the tip protruding slightly into the chamber, and film cool it with fuel from the cooling channels. This didn't work before, but after reaming out the orifice a bit, it held up perfectly this time. Thrust was a bit higher on this test, as the LOX tank pressure setpoint was increased over the last one, in addition to swapping out our pressurization solenoid valve for one with a more powerful coil and higher CV value. But, LOX tank pressure fell just as quickly as before, which is observable as the exhaust plume turns fuel-rich about one and a half seconds into the test. The only other chokepoint in the system is the regulator on the compressed gas tank. We will be upgrading to a regulator which a much higher flow capacity to ensure our O:F ratio stays at 2.2:1. Be on the lookout a couple weeks from now as we also just ordered much larger propellant tanks, about 5x more capacity as our current tanks. We should be able to test up to about 20 seconds!!

[tirus]

That little smoke ring at the end is nice.

[mmb]

Does just the camera make the plume look wierd or is it actually like that, if the latter how come the flow is so wierd?

[maxumus]

Came back to this channel after seeing the new batmobile

[alexjshank]

Are you doing any force measurements yet? looks like the cart is on wheels so I wonder if you could just put some measurement setup between the cart and the wall.

[renkeludwig]

Aye man i LOVE this.
This has always been my dream!
Do you have any info on what the thrust of this beast is?

[saeednajafii]

What’s the weight of engine if it’s fully loaded?

[dsdy]

Are you employing film cooling around the nozzle or something?