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Post Info TOPIC: Aurora speculation thread (rational discussion only pls)


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RE: Aurora speculation thread (rational discussion only pls)
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Leela25 wrote:
retroistic wrote:

An Aurora thread on this forum? Times are a changin'!

I'm half expecting this discussion on aerospikes to somehow coalesce with the "donuts on a rope" contrails. They always seem to.


 IKR?? what was i thinking *headdesks*

Only hatters who have not a clue what an aerospike is would connect the two. The pulsejet explanation is equally absurd. Sometimes i see both theories mashed together. Doughnut contrails happen wih anything that make contrails... they are commonly caused by turbulence or ambient wind conditions.


 Tell me about it. If a pulse jet were to detonate at such low intervals to create rings like that it would be a pretty sh1tty pulse jet. The pulses are timed at several hundred per second, you wouldn't even be able to comprehend it.

 

Rafale D wrote:

what was the overall conclusion?


 Probably the same as her "short answer" to the question of why they aren't mainstream.



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Guys, can we get serious and let this old myth die already? It has been proven that Aurora does not exist so why spend so much effort debating the aerodynamics behind a nonexistent aircraft?



-- Edited by retroistic on Tuesday 5th of May 2020 04:51:09 PM

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You seem like a blast at parties, retroistic.



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And you come across as overly sensitive about a simple comment about maintaining rationality on a forum with a low tolerance to speculative nonsense. But don't mind me, go ahead and have your fun. It's not up to me anyway.



-- Edited by retroistic on Tuesday 5th of May 2020 05:24:23 PM

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No need to be so spicy. No one's justifying the existence of Aurora, just some of the phenomenon that indignantly carry the label.



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Second on Anthony's response. Of course "aurora" is bs, but the reports are a bit more grounded in reality. Consider "Aurora" as an umbrella word for the phenomena and the same should apply to the name of the thread. Or you could just separate the name from the reports like i do. We are not saying that the reports = Aurora, instead we are attempting to separate the label and its stigma with rational speculation for these repors.



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Pepper wrote:
 Tell me about it. If a pulse jet were to detonate at such low intervals to create rings like that it would be a pretty sh1tty pulse jet. The pulses are timed at several hundred per second, you wouldn't even be able to comprehend it.

 Well it depends, some are less than one hundred( the nazi V1 had a valved pulse jet that had a frequency of 45 per sec which made a buzzing sound) but yea the the frequency is too close together to be the root cause of a pattern like that. Especially if it were a valveless design which would be more appropriate for a theoretical hypersonic vehicle.

Rafale D wrote:

Informative answers are the best kind, thank you.smile

Now to be constructive : Why would you want to use it as a re entry shield when the SSTO lifting body is designed with adequate heat shielding? Besides, even if you did, I think that if it can withstand the extreme temperatures of rocket thrust it can handle atmosphere friction. The fuel type could also play a part in temperatures, if you used a denser type with higher heat absorption it should aid in temperature reduction. My impression is that an aerospike is flexible between solid and liquid fuel and should be able to handle a cryogenic fuel type. You seem to have a better grasp of rocket science tho so I'm eager for some schooling.

How did they handle these problems on the SR-71 aerospike and what was the overall conclusion?


 Because you can.....

Think about it, it CAN withstand the extreme temperatures so you can design a craft that will utilize it as a reentry shield if you need to... especially if it were a plug nozzle (see Phil Bono ROMBUS) they are sometimes classified differently from an aerospike but they are essentially the same thing just truncated. Remember they are heavy relative to a craft's center of gravity so you can use this mass to an advantage... doesnt work so great with SSTO design like the X-33 though and was a major concern that prompted full integration into the structure. Cooling can be achieved by actively circulating liquid hydrogen through the engine cooling system at the base while the engines are still active, before it enters the combustion chambers. You don't really need cryogenic fuel for this kind of cooling method, hell water circulation will work. Obviously the linear aerospike of the X-33 would not work with ballistic reentry... hypothetical SSTOs of this type are usually designed for noseward reentry per Air Force/DOD requirements for cross-range distance anyway. It's not so much that an aerospike can't work at all, as a shield, but more of whta kind of aerospike and the craft it was designed for. The cooling method I described is fine and dandy in theory, but it's still an engineering hassle to integrate efficiently and quite costly.

It doesnt matter, all of this is purely theoretical since the LASRE is the only form of aerospike to have ever been flight tested. the SR-71 aerospike was never hot-fired during flight tests because of a liquid hydrogen leak in the LASRE pod... they only cold-flow tested it plus some hot tests on the ground. Not much data is available because the programme is essentially dead, so the results are inconclusive. Bottom line is cost and politics... the biggest issues to overcome in any development in aerospace over all else. :P

OMG this was a pain to retype!!!! and i stayed up late just to do it... AB servers being mean. xp



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I'm so confused. So are you saying a linear aerospike nozzle can be used as a re-entry shield or only the plug nozzle? And if the cooling solution can theoretically consist of water circulation then I don't understand the complexity or why it would be so costly. Love your input and would appreciate some more.



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retroistic wrote:

And you come across as overly sensitive about a simple comment about maintaining rationality on a forum with a low tolerance to speculative nonsense. But don't mind me, go ahead and have your fun. It's not up to me anyway.



-- Edited by retroistic on Tuesday 5th of May 2020 05:24:23 PM


 I'm not being oversensitive, who is being oversensitive lmao?? I responded to the fact that you just seemed dead set on shutting our conversation down because the word Aurora somehow triggered you. We're all being civil here.smile



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Water circulation is dual purpose for cooling and injecting into the airflow to increase air density, which increases thrust because the compressor operates at higher than normal levels. Really old trick but it works if done right (you can be faced with affected booster ISP.) DARPA RASCAL Phase 2 ground testing was able to achieve around Mach 5 through LOX and water injection. The specific form of water matters too: ordinary tap water was used in cooling the LASRE unit and caused burn-through due to CaCO3 buildup in the coolant vessels, and decreased combustion pressure. De-ionized water is safer and more efficient.

Get over yourself, you also protested the topic right in the beginning of this thread so stop being a hypocrite. I'm not shutting anything down, I asked a question (well two actually) and let you on your merry way. You're the one who's triggered, not me.



-- Edited by retroistic on Friday 8th of May 2020 08:59:45 PM

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What you call protest I call having an opinion and moving on with my life, which you should try. You call me a hypocrite but here you are, still posting in this thread after being high and mighty about it. At least I'm willing to stick around since the discussion evolved into a pretty educational area for me. I'm not here to cause a stir like you did.



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omg pls calm down... there is literally no need for hostility.

Yes retro taht technically works but only with a breathing engine system like SABRE and RASCAL's F100 turbofan or something like these. Solid/liquid chemical propulsion is a bit different... you could mix in antifreeze and circulate through a closed cycle system but you suffer a weight penalty since the system's complexity adds excess mass to an already heavy aerospike nozzle, and besides water would most likely be wasted in the burn process so it's only useful as a closed cycle coolant (higher thermal absorption rate). TBH you'd be better off with a regenerative liquid oxygen cycle or a mix of both... a hydrolox system.

Both aerospike designs could work as a shield but a plug nozzle would be more efficient for its shape in combination with an aerodynamic body that allows such. like i said, anything like the X-33 would obviously not work since the lifting body is designed for noseward entry. ROMBUS is a better candidate for ballistic reentry.

But like i said also... all theoretical. No real life basis to go on since the LASRE was the only arospike that was flight tested.

i failed to specify the differences in my last post, sorry i was tired xD



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retroistic wrote:

The specific form of water matters too: ordinary tap water was used in cooling the LASRE unit and caused burn-through due to CaCO3 buildup in the coolant vessels, and decreased combustion pressure. De-ionized water is safer and more efficient.


 this is also true but can i nitpick a a bit? The buildup occured in the circulation system i.e. the coolant lines, not the vessels (the tanks, assuming you meant "vessels" as in containment vessels?) not sure what context of the word you're using lol

IIRC this was one of the ground hot-fire tests. The initial decision to use regular tap water still boggles my mind...



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Rafale D wrote:

What you call protest I call having an opinion and moving on with my life, which you should try. You call me a hypocrite but here you are, still posting in this thread after being high and mighty about it. At least I'm willing to stick around since the discussion evolved into a pretty educational area for me. I'm not here to cause a stir like you did.


 Just stop. You're a contradiction down to calling yourself Rafale D while sporting an F-5 avatar LOL. At this point I'll take my leave as I have no interest in quarreling with you. I have better things to do with my time.

Yes Leela, I was referring to the overall circulation system not the holding tanks. "Vessel" refers to a fluid channel or duct system too, not just a method for containment.



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Some hot tempers in here, gentlemen. Life is too short to waste time arguing about pointless semantics instead of appreciating each other's feedback. Can't we all just get along?



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retroistic wrote:
Rafale D wrote:

What you call protest I call having an opinion and moving on with my life, which you should try. You call me a hypocrite but here you are, still posting in this thread after being high and mighty about it. At least I'm willing to stick around since the discussion evolved into a pretty educational area for me. I'm not here to cause a stir like you did.


 Just stop. You're a contradiction down to calling yourself Rafale D while sporting an F-5 avatar LOL. At this point I'll take my leave as I have no interest in quarreling with you. I have better things to do with my time.

Yes Leela, I was referring to the overall circulation system not the holding tanks. "Vessel" refers to a fluid channel or duct system too, not just a method for containment.


 Wow dude you're reaching. I have never seen someone so desperate and immature to try and win an argument. If you really weren't interested you would not still be posting. Please just save yourself more embarrassment and let it go... By the way thanks for your response to my questions, Leela. As always you deliver. This forum definitely benefits a lot from your expertise.wink



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as for cooling have you ever seen a diode cooling matrix? Had some guys at Corona airport build a prototype DC electric in and the device would heat on the anode side and its 'waste' heat was just to an outlet to room air and the cathode side would be freezing and the frost would build up on it'

They put a water jacket and a pump on the cold side and the water would go into a mask a person would place on areas of plastic surgery.

adjust the temp with power input / loop feed back control... the matrix device was 2"x2" 1/4 inch thick....scaled up could it help pilots/instruments?

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Rafale D wrote:
retroistic wrote:
Rafale D wrote:

What you call protest I call having an opinion and moving on with my life, which you should try. You call me a hypocrite but here you are, still posting in this thread after being high and mighty about it. At least I'm willing to stick around since the discussion evolved into a pretty educational area for me. I'm not here to cause a stir like you did.


 Just stop. You're a contradiction down to calling yourself Rafale D while sporting an F-5 avatar LOL. At this point I'll take my leave as I have no interest in quarreling with you. I have better things to do with my time.

Yes Leela, I was referring to the overall circulation system not the holding tanks. "Vessel" refers to a fluid channel or duct system too, not just a method for containment.


 Wow dude you're reaching. I have never seen someone so desperate and immature to try and win an argument. If you really weren't interested you would not still be posting. Please just save yourself more embarrassment and let it go... By the way thanks for your response to my questions, Leela. As always you deliver. This forum definitely benefits a lot from your expertise.wink


 Whatever. Stay mad. I don't care.

Hillberg, yes that could work for individual flight components and instruments, but it would fail as an engine cooling method. It would literally melt at the extreme temperatures inflicted on it from both the propellant burn and heat friction.



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*sigh* thanks for confirming that i had made a mistake creating this thread guys. Locked.

Feel free to argue amongst yourselves in PMs i guess. :P



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