Re: Atmospheric Flight to Orbit


"Craig Fink" <WeBeGood@xxxxxxxxx> wrote in message
news:LRfGh.5877$PL.3762@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Cool, so your engine is an attempt to bridge the ISP gap between jets and
rockets. Sounds like it does.

A child must learn to crawl before it can walk, then walk before it can
run.
Sounds like your engine is in the crawling stage of Atmospheric Flight to
Orbit. Does your engine take you from 0 to 5k-6k fps with an ISP of 1000+?

It is an engine concept with a reasonable chance of working, not hardware.
It would be usefull to about that speed if very active measures were taken
to handle intakes and thermal problems. The variable intakes to handle that
mach variety mass more than the engine itself. The heat loads on the
vehicle
and engine through that range add considerable mass, complexity and design
problems.

It also sounds like your study was attempting to run all the way to Orbit.
An SSTO? If you turned the engine off, you should have dropped it. What
was
your performance gain when you turned the engine off? Could I have a copy
of your paper? Sounds like interesting reading.

I didn't do a formal paper. To get an idea of the concept, look up
air-turborockets.
Then check out centrifugal compressors and radial inflow turbines. My
concept
recognizes the similarity between a squirrel cage fan and those two
turbomachines
to give a regen cooled engine.

My point is that I have a vested interest in air breathing engines for this
purpose,
and they fail.
--
Craig Fink
Courtesy E-Mail Welcome @ WeBeGood@xxxxxxxxx
--

john hare wrote:


"Craig Fink" <WeBeGood@xxxxxxxxx> wrote in message
news:zRWFh.7664$_73.5431@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
I would think that the advantages of airbreathing engines are tremendous.
A
payload increase in the 100% to 1000% range. There is a huge performance
gap (ISP to SPF Specific Fuel Consumption) between rocket engines and
airbreathing engines. From 600 for the best chemical rockets to the
1000-4000 for airbreathing engines. Doubling the ISP of the best rocket
engine will more than double the payload.

In my opinion, not much has been done or studied to bridge this gap. If
your
trades don't give a serious advantage then something is wrong with your
trades. Like, maybe they had the wrong engine.

The regulars here have excersized diplomacy in not pointing out that
I have a vested interest in finding a use for air breathing engines for
spaceflight. I did a short talk on an air breathing engine I invented
at Space Access 04. On paper it should have a very high T/W ratio
with fair fuel consumption. Better than any jet flying today. I did
the trades. On pure performance, pure rocket wins every time. I
have to find other reasons to justify use of my concept.

The ABE Isp is only good for narrow bands of speed and altitude. The
very high weight of most air breathing engines is dead mass for the
rockets to carry from their cut off velocity to the vehicle final
velocity. That dead mass eats up far more fuel than is saved in the early
climb. My concept engine, a variation on the air-turborocket, should get
25+ to 1 thrust to weight, with an Isp well over 1,000. The trades still
don't close for it on performance alone.



.

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