Sea dragon and Big Dumb Booster.

> I'm certainly no rocket scientist. Can anyone give me a basic outline of
> the causes of combustion instability? Is this something that we can iron
> out of designs with dampening devices and computer modelling?
>
Causes: vibrations in the feed line, resonances in the combustion chamber
working as an organ pipe,... There are two remedies: Put a Helmoltz resonator
to dampen vibrations, or use a pintle injector to get a better fuel mixing.

> The Sea Dragon BDB, designed in the early 60's anticipated the use of a
> single, huge pressure-fed first stage engine, producing 36 million Kgf of
> thrust. Since the design was never built and tested, are we to assume that
> the designers of the early 1960's were ignorant of POGO effects?
> http://www.friends-partners.org/mwade/lvs/searagon.htm

The Sea Dragon problems are not technical, they are monetary, Where do you
find the billions to build the first unit?

The only workable alternative is a OTRAG-like design with up to 600 smaller
rockets. Each could have the theoretical possibility to launch may be 2000 kg
in LEO and would have a mass in the 60 - 80 t at take-off. A 120 thrust motor
would do the job on each elementary rocket. Using the V2/A4 injector
clustering technique, such a motor could be derived from a 1/20th scale
system or 6 - 7 t thrust motor, something in the range of amateur desing. I
am working on such a concept for some time now. The first version of that
motor would be itself a 20 cluster, each element with a thrust in the 500
lbf domain. This first step has been ground tested.

Would you be interested in that project? If yes, I can even tell you how to
make money with it right now (no risk, no money going out of your pocket!)

Yvan Bozzonetti.