On 7/20/2014 3:39 PM, Przemek Klosowski wrote: > The trick with rocket engines is to prevent them from burning themselves up > while burning the maximum amount of fuel. Therefore, it's a complicated > fluid dynamics/thermal management problem, with fuel lines cooling the > combustion/expansion chamber, turbo pumps working against pipe and flame > back pressure, etc.
Also closed VS open cycle turbopumps. Turbopumps burn rocket fuel and oxidizer to spin high speed turbines, which drive other high speed turbines that pump the majority of the fuel and oxidizer into the combustion chamber. Electric pumps or pressurized (blow down) tanks with gravity feed worked for small rockets but as size and power increased those methods couldn't feed the fuel fast enough. From the start of the rocket age, most rocket scientists declared it an insurmountable problem to feed the turbopump exhaust into the combustion chamber so the gas wouldn't be wasted. The pump exhaust was just dumped out a pipe off to the side and accepted as an unavoidable efficiency loss. Attempts to create a closed cycle engine generally resulted in things exploding. How do you feed relatively low pressure pump exhaust into the high pressure combustion chamber, without having that high pressure push back up to the pump and blow it apart? "Dunno, I guess we just can't." said the scientists and engineers. Meanwhile in the USSR, rocket scientists decided they would figure out how to build closed cycle engines, no matter how many exploded or failed in other ways. Every failure was just eliminating one more way it wouldn't work. The efficiency boost was critical because their main launch rocket (a version of which is still used to this day) uses over 30 separate engines in its first stage. That's what was the downfall of the Soviet Moon program. They tried to scale that concept up (instead of going with fewer but much more massive engines like the Saturn rocket) but were unable to ever get one of the N1 rockets' first stages all lit up without at least one engine failing and causing a big fire or a rather large kaboom. The US thought one of the N1 launchpad explosions was a small aboveground nuclear bomb test. More engines, needs more fuel, more weight, needs more engines which need more fuel... One bit of leftover from the N1 was a warehouse full of the engines, and all the documentation required to build them. It was all saved by the people who built them, in defiance of orders to scrap it all as part of sweeping the entire debacle under the rug. After the breakup of the USSR, Russian officials were delighted to discover they still had that technology to sell to other countries. The production and modernizing of those engines was put back into motion while some of the "barn find" old engines were fitted to some American rockets, but in single units. If you have some free time, look up the Kerbal Space Program. It's not a game, it's a massive time sink that'll draw you in while you attempt to build virtual rockets that don't fall apart and explode, or explode then fall apart. ;) Conveniently available for Linux, Windows and Mac OS X. The 64bit versions are a bit more buggy than the 32bit versions. Huge numbers of KSP videos on Youtube if you just want to watch. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com ------------------------------------------------------------------------------ Want fast and easy access to all the code in your enterprise? Index and search up to 200,000 lines of code with a free copy of Black Duck Code Sight - the same software that powers the world's largest code search on Ohloh, the Black Duck Open Hub! Try it now. http://p.sf.net/sfu/bds _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
