| Author | Message | ||
     Boogiman1981 |
http://www.reuters.com/article/2012/11/28/us-scien ce-spaceplane-idUSBRE8AR0V220121128 Smoke and mirrors or real? | ||
| Ducbsa |
"remarkable heat exchanger that is able to cool air sucked into the engine at high speed from 1,000 degrees Celsius to minus 150 degrees in one hundredth of a second." I would think the exchanger surface area and pump for that would be pretty darn big. | ||
| Darth_villar |
Color me skeptical. Mathematically conceivable is a long way from physically possible. When looking for investors, many things can be exaggerated. It will be pretty cool and impressive if this accomplishes what they say it can do though. | ||
| Chauly |
Wouldn't that be "cool and compressive"? Sorry... | ||
| Hootowl |
Actually, it would be compressive and then cool.  | ||
| Ducbsa |
We need to rename this forum the "Witty Forum".  | ||
| Nobuell |
It seems physically impossible to me. The size of the fluid to air coils we use just to change air temperature 40 deg f are quite large with much lower air velocity. Something does not sound right. It is all a matter of surface area, fluid temperature and air velocity. There are no magic bullets. Simple physics. I am not sure how much air a jet engine uses, but it has to be quit a lot. Reducing the air temperature 800 deg in a single pass, would need a lot of surface, a huge refrigerant plant and it will have to have a huge pressure drop. | ||
| Boogiman1981 |
1,150C temp drop. my thoughts were similar how can this whatever it is get around the known laws of physics and thermo-dynamics? the amount of intake air at the advertised speeds for a craft big enough to be worth while, tons and tons per second... | ||
| Hootowl |
I agree, it seems fantastic. All the same, I hope they find the private funding they seek. No private entity would cough up 400 million for a pipe dream. A government would. Ours, specifically. | ||
| Pikeben08 |
Sounds to me like somebody forgot to carry a 1. Or maybe they used millimeters instead of feet or something like that failed Mars probe. | ||
| Kenm123t |
adiabatic cooling what is the pressure drop? 1000c at what pressure and the 150 below at what pressure ? | ||
| Aesquire |
Interesting.... I'm a bit skeptical, but Perhaps they've got a new trick. Not the first time accepted wisdom has been wrong. ( or we'd still be using low pressure steam engines ) My question is, why bother with turbojets at scramjet speeds? We're still working on that, the USAF has had problems getting theirs, the X-51a, to run for an extended period. http://www.space.com/17091-hypersonic-waverider-ho w-the-usaf-x-51a-scramjet-works-video.html ( in a fit of remarkable stupidity, they are using throwaway test drones.... the Navy figured out decades ago it's cheaper to re-use them... but they have Chance Vought to thank for that with the Regulus program.) http://en.wikipedia.org/wiki/SSM-N-8_Regulus ) For a practical approach to orbital craft, check out Darkhorse. http://www.risacher.org/bh/analog.html http://www.ai.mit.edu/projects/im/magnus/bh/bh-faq .html |
