LostCosmonaut

B-57 ripoff

I made an attempt at a Tu-22, came out alright, I guess.

I believe the implication was that the stated power density was ludicrously high. I haven't seen the calcs though (and if I had, I wouldn't know how to make sense of them), so I'm not sure.

Based on my (admittedly brief time in a nontypical portion of the military) experience, this is broadly true.

Today I learned that the NSWR probably wouldn't work. Showed Zubrin's paper to my nuclear propulsion professor, who had the following comments (quoted verbatim): Geometry will not go critical at 20% enrichment Neutron flux = 3.5*10^17 neutrons/(cm2*sec), turn steel to jelly in minutes - rad damage Power density = 232 MW/cm3 - yeah right Heat flux = 700 MW/cm2 - heat flux will melt wall no matter what Made many terrible assumptions on boundary conditions Back to fantasizing about gas core NTRs and Orion drives instead.

I always thought this was more Tied's speed;

Would larger rounds (15-20mm) be easier to manufacture with shitty machine tools? Autocannons for the people!

Music to trip balls to:

This thread is intended to be a place for cool things that you just found out about, but that aren't necessarily major enough to merit their own thread. For instance, today I learned why heavy water is/was used as a moderator in certain types of reactors. Since hydrogen atoms are small, they are very good at slowing down neutrons, but regular hydrogen also has a nasty tendency to absorb said neutrons (which you probably want to be absorbed by the uranium/plutonium in your reactor). Deuterium is a bit heavier, but still pretty damn good at slowing neutrons, and it's much less likely to absorb them.

For reference, gamma in air is aboot 1.4. Helium is one of the highest at about 1.67. I think most exhaust gases for solid rockets are about 1.2-1.3ish, so I'd bet that gun gases are about the same. Also, the most thermodynamically efficient AR-15;

For something different, this recently popped up in TS;

Goon Sunday Punch talks about nuclear rockets of various forms;

This was original posted by goon Vessbot in the Aeronautical Insanity thread, but since some people here are poor and can't afford $10, I'll copy it over to here;

A Nazi Germany that somehow got functioning nuclear program, but is still as shitty as ever at turbines? I don't think a cold bleed reactor has ever made it to the build stage (we had hot-bleed in the 60s), but theoretically if you really wanted to you could make one.

So, this exists;

Some highlights from my recent Norway game (starting in 769): The Byzantines going Iconoclast, then Orthodox again. The Ummayads owning all of Spain, and part of France. The northern shore of the English Channel being owned by Norse pagans. Me plotting to kill my firstborn and secondborn son so that my genius third son can inherit the throne. Said genius son marrying a Tengri Khazar in order to acquire their superior genetics.

I still wish Nemesis existed.

I recently began a class on nuclear rocket propulsion, and one of the first topics covered was various nuclear rocket cycles. I'll do my best to explain them using amazing MS Paint drawings and words. The first is the hot bleed cycle. In this cycle, some propellant does not go through the reactor, but is instead shunted off in a different direction. This is mixed with some of the propellant that has passed through the reactor, but not out the rocket nozzle, creating a relatively hot stream of propellant. This propellant is passed through a turbine, which then powers the fuel pump. After passing through the turbine, the propellant is exhausted overboard (on some designs this can be used for attitude control). Since the propellant that has passed through the turbine is at lower temperature than that which has passed through the reactor, some efficiency is lost. The NERVA design from the 1960s/1970s utilized the hot bleed cycle. The cold bleed cycle is similar, except no propellant from the reactor is used to power the turbine. As a result, the propellant passing through the turbine is colder, thereby reducing turbine efficiency. However, this does have the advantage of producing less thermal stress on the turbine components. However, since the mass flow through the turbine is larger, the cold bleed cycle is less efficient than the hot bleed cycle. The expander cycle cleverly avoids propellant wastage by passing all the propellant used in the turbine back into the reactor. This avoids expending propellant in the relatively low temperature turbine exhaust, and means that the expander cycle NTR has a higher specific impulse than the hot or cold bleed cycles.

I went on the internet, and I found this;

At the altitude the pitcharound would have taken place at, air density would have been virtually nil (the maneuver was to have been done propulsively). So control authority would have been virtually nil, until you got down much lower (at which point you'd be back to positive alpha).

Most of them are, yes.

I recently came into posession of some video clips related to nuclear propulsion, so I thought I'd share them;