MILESTONE: Launcher's 3D printed Copper Alloy E-1 🚀engine test was a success.

MILESTONE: Launcher's 3D printed Copper Alloy E-1 🚀engine test was a success. Reaching for 30-seconds the highest temperature for LOX/RP-1 (mix ratio 2.8) without any damage to the chamber. The highest performance rocket engines are made of copper alloy - but we only recently had access to 3D print copper alloy (CuCrZr) thanks to our partner EOS and their M290 machine. Most 3D printed rocket engines are produced today in Inconel alloy - which is a compromise in terms of cooling capability usually requiring a lower combustion temperature and as a result a lower performance engine. 3D printed copper alloy is the solution when performance matters.
Next step - Increasing in steps the combustion pressure to reach our E-2 flight engine goal of 1,400psi. #3dprinted #propulsion #copper #cucrzr

[aavkashyaan]

Which fuel you used? How much thrust is produced?
And please make video on How to design a nozzle

[AlexanderBatyr]

Wow, it looks exciting. Do you plan 3D-printing engine bell for E-1?

[bhuvanachandrabr]

is there a specific point in the flow velocity or injection pressure at which u start to view Mach diamonds or is it like exhaust pressure or reaction vessel pressure dependent ?

[robertclark]

I had question I wanted to ask. It concerns highly reusable rocket engines. I have a theory that the reason why jet engines can operate for thousands of hours total but rocket engines at best a few tens of hours total is because of the temperature they operate at. A jet engine may operate at ca. 1, 200 C, while a rocket engines at ca. 3, 000 C.

The temperatures for rockets are well above the melting points of the metals composing them, requiring methods such as regenerative cooling to keep them from melting.

So I wanted to see what would happen if rocket engines operated at lower temperatures such as jet engines. The method I wanted to use for testing this was to operate at a highly fuel rich state. I'm aware that rocket engines normally operare below the stoichiometric ratio, but I wanted to operate well below even this.

For example for a kerolox engine, the mixture ratio might be ca. 2.3 to 1. But I'm thinking of going even to below a mixture ratio of 1 to 1.

If my theory is correct the rocket engine will also be able to operate for thousands of total hours.

This will degrade performance of course as measured by Isp. But my ideas is operating at lower temperature, and necessarily also lower pressure, thinner walls and lighter weight materials could be used.

But the investigation into that can wait. The first thing is to test that operating at such reduced temperatures really does result in radically lengthened operation times.

Note this is something that can be tested by amateurs with pressure-fed engines. Ironically, it would be easier to test by amateurs with their pressure-fed engines.

The reason is most professional rocket production companies use pump-fed engines for performance sake. These are harder to change the mixture ratio because the gear ratios between the fuel and oxidizer pumps are usually fixed.

[roxannamason]

Largely untapped technology, high power fiber lasers are changing this as they enter the field. Ken