NARloy-Z and the aerospike

60 years ago Rocketdyne Corp introduced the Aerospike rocket engine

implementation as a lift device never occurred

but a new high temp alloy lining conventional bell shaped engine nozzle was developed-- NARloy-Z

the story----------

Aerospike Engine - YouTube

In the video they're proud of the extensive testing, to include "73 engine hot fire test and 4000 seconds of operation" a whole hour and 6 minutes.
A very expensive hour I'm sure, but interesting that run time is measured in seconds for such a large, complicated, and expensive engine/assembly.

Most rocket engines can run for only a short time, overall, the conditions inside one are beyond "brutal". But they do a lot of work in that short time.

The use of seconds does not surprise me at all.

If you read of the toxic waste dump they left behind, you'll get a better
sense of "Expensive"....

digger doug said:

If you read of the toxic waste dump they left behind, you'll get a better
sense of "Expensive"....

Click to expand...

You should see what reaction motors left up here lol

plastikdreams said:

You should see what reaction motors left up here lol

Click to expand...

Don;t leave us hanging, provide some more info.

AFA rocketdyne, google "SantaSusana" Rocket test station.

IIRC 2 million gallons of carbon tet, 1 million gallons of Trichlor
all dumped.

Military portable Nuclear powerplant experiment melted into the ground.

On and On.

Grigg said:

In the video they're proud of the extensive testing, to include "73 engine hot fire test and 4000 seconds of operation" a whole hour and 6 minutes.
A very expensive hour I'm sure, but interesting that run time is measured in seconds for such a large, complicated, and expensive engine/assembly.

Click to expand...

Aero spike engines are intended for orbital boosters; rockets that need high-performance engines operating across a wide range of altitudes (sea level to vacuum).

Most boosters only fire for 3 minutes before going empty and falling back to earth as trash. No mission has ever required a first stage engine fire for longer than 10 minutes (600seconds). So yes, 4000 seconds is an eternity in the rocket world.

And start/shutdown cycles are very hard on rocket engines (due to thermal transients and fatigue), so 73 different firings on one engine is actually pretty impressive.

Rocket engines live very short, violent lives.

Alloys with similar properties are Amzirc and Glidcop - thermal conductivity close to copper but but much better tensile strength at elevated temperatures, up to 700 °C. Some twenty five years ago ago I was working on a project using Glidcop; just about the time the material became available commercially. It machines nicely, even better than pure copper.

"Short violent lives".... Yep.

Consider the equivalent HP rating of the engine, which is actually relatively small. The HP per cubic centimeter, or the thermal energy per cc.

A buit of digging on google turned up several references with various data.

Just the gas generator to run the pumps for the Saturn F1 engine is stated to be 55,000 HP. Just for the fuel pump on one engine.

The HP rating of the actual engine depends on the speed, so it is a bit hard to specify. But I have seen ratings in the many million HP for the F1 when near engine cutoff (fastest speed).

The entire engine was nearly 20 feet tall, but the actual combustion chamber was much shorter and smaller, a few feet in diameter and length, not that much bigger inside than a 55 gallon drum, yet it burned something like 650 gallons of fuel per second, at a pressure of 1000psi and temperatures around 3000C.

It is impressive that anything could do that for the 2 or 3 minutes necessary to boost the rocket to 40 miles high and 6000 mph.......