hydrogen ISP in scramjet? 2000 ton oribal sto?! Now methalox or kerolox. FLYING AEROSPIKE!!?

[Arugela]

Is it true that a scramjet can get 1200-2700 isp from a scramjet?

I'm making a fantasy bomber/cargo plane and trying to figure out how it could fly. It's a bit over the top, but if that ISP can be obtained I think it could go to orbit. Even with it's massive 2000 tons to orbit max take off weight goal! 8)

https://www.researchgate.net/figure/SP-of-MI-Martian-Ramjet-Scramjet-engine_fig13_346778009

Most things say hydrogen in rockets are only 430-460 at most. Is it different for scramjets?

On a side note. Can liquid hydrogen be converted into a salt or similar form and reconverted for fuel to increase density? I've seen stuff on hypothetical metalic hydrogen that will get near 1200 isp. Are there any other solid forms besides metalic that could be used?

It's built partially around the idea of collecting water and converting it. Even though I've seen it's cheap enough for all fuel, I'm making the ship into a giant flying chemistry set just for the potential of fuels or converting resources. Especially if it can help build/maintain the vehicle to lower overall long term cost and building or other function. No idea how to do that, but it's fun trying to figure out. Possibly useful at minimum for space debri patching or something without having to get out of the ship.

One idea is for it to turn into cryogenic freezing near the engines for better cooling. Then solid in the ship interior. Potentially with permanent magnets in the hull structure and similar for passive power on top of any potential engine power.

That and the idea of covering the hull in cold plasma/air to get more lift and reduce drag in a programmed manner to enhance the aircraft.

Edited January 27, 2022 by Arugela

[SargeRho]

Scramjets, and really any atmospheric jet, gets much higher isp than rocket engines would. Turbofans can get well into the thousands of seconds. The reason is that they're not carrying internal oxidizer and remass, most of the reaction mass of a jet engine is the air.

[Shpaget]

Wikipedia has ISP of RR Trent 1000C at 13 200 s. But that is meaningless for spaceflight since turbofans, just like any other airbreathing engine can't operate in vacuum (the term "airbreathing" in the name should be a clue).

Converting substances back and forth can be done but is always going to cost energy and require additional equipment, and you know what they say about mass when it comes to space travel.

Permanent magnets for passive power? What does that mean? There is no energy in a magnet that can be harvested.

[Arugela]

If it uses large amounts of liquid oxygen and helium I was hoping it could go from possibly the ocean or land to air then space. Or just ground to space.

If it could get a lot of unfinished tonnage and some robots to space you could build lots of stuff in orbit. Or maybe get it to the moon. It's based on 5ft diameter tubes for holding moab bombs and stuff the b2 and b-52 can drop. I wonder how hard it would be to get a full cargo of up to 1500+tons to orbit. I think the max cargo is just under 1700 tons for what I somewhat randomly allotted. I gave it a somewhat low 288,000 lbs or 144 tons of fuel total. With 1200-2700 ISP It look like it should make it to orbit. I was hoping to use extra air from the body to pull in air to increase the flow so it could hit super/hypersonic at lower levels. Or just plow through with a lower end turbofan engine or something.

 

Edited January 23, 2022 by Arugela

[wumpus]

Remember, the fundamental issue of the rocket equation is that to accelerate, you need fuel.  And then when you do accelerate, you are "paying" to move all your fuel as well.  Ramjets and Scramjets don't need to carry, and thus accelerate, the oxygen.  Hydrogen is absurdly light (although the density is an issue), so extreme Isp is possible.  Also expect Isp to reduce as you increase speed.  2700s Isp is probably only going to happen during the initial acceleration and the overall Isp will decrease (to less than rocket Isp by orbital speed).  Unfortunately I couldn't find the "free online" paper for the X-43, but that includes all the best data about the fastest hydrogen Scramjet to fly (no idea if the Australian project was hydrogen, the Air Force's follow up uses kerosene).

Aren't salts what you get when you strip excess hydrogen from acids (I was a lousy chemistry student, so maybe not).  In any event, you would be carrying far too much mass of "not hydrogen", no matter how much hydrogen you could shove in a molecule.  The whole point of the fuel is low mass (it isn't all that energetic).  Similar for cracking water.  This only works if you cracked it *before* accelerating, and then either discard the oxygen or use it for some other purpose (possibly saving some for final orbital insertion.  But most of the oxygen wouldn't be needed).  Also realize just how inefficient cracking water is, and you'd probably need a nuclear reactor (you probably don't want to send it and its shielding to orbit).

Metalic hydrogen, more specifically meta-stable metalic hydrogen, doesn't appear to be a thing.  The idea was that you could apply sufficient pressure to turn it metal (this may have happened), and when you lower that pressure it would remain metalic.  This doesn't happen.  Metalic hydrogen was assumed to not only be an ideal way to store hydrogen, but "monatomic hydrogen" which would be an ideal monopropellant (think nuclear levels of density and energy).

As far as I know, the shuttle had the hydrogen about as dense as it gets, and the fuel tank was mostly hydrogen by volume and mostly oxygen by mass.

One last thing about hydrogen.  Being the lightest stuff around it is also the best form of rocket exhaust (assuming you are generating momentum by heating).  It is by far preferred for nuclear thermal rockets, solar or microwave heated rockets, and hydrolox rockets not only run fuel rich to save the engine from melting (many rockets do that) but also the theoretical ideal mixture of hydrolox is fairly fuel rich to gain the benefit of heating up all that hydrogen (even if doing so lowers the temperature of the exhaust).

[Arugela]

If I'm doing my math right. I did 288,000 lbs of fuel.

This says: 4.432 lb/ft3

If I'm not mistaken that is 42x42x42?

2*42x42x21

That might fit in the dimensions of the plane. Mostly the stub past the cargo and into the wings.

It's starting as a diamond shape 166.5 ft wide * 96 ft long* 30+ft tall. It's basically a diamond B2 with a much fatter body and must fatter wings from top to bottom. I think that perfectly fits in the wing structure outside of the bombbay/cargo. If the plane does an aerospike in the body it only needs 2*sr2200's or 4*xsr2200's. the fuel cold be in front and the air could come from the front I assume. the pictures with engines are for top and bottom SR71 engines. 24 in total. Would the X/SR2200's be lighter overall? I couldn't find total weight. I gave 72 tons for engine that might not be needed.

cargo is 5ft diameter tubes that are 72 ft long. I'll get a picture.

https://imgur.com/5245Pgg

If I added three more tubes on the ends I think it would cover half of the 288,000lbs of fuel approximately. 12-15 tubes of Liquid hydrogen total after you consider the ends get smaller as you go past the center core of cargo tubes.

I came up with this idea for a flap/aerospike combo:

It's internal structure could allow the flaps to extend /retract. It might also help with elongating the thrust if it helps. Might need the crygenic cooling inside it though to help cool it. I assumed cold plasma between the plasma and aerospike surface +cryogenics flowing through the metal to help cool.

Any gas left over could be used to help cold plasma/air surface the plane to control the relative drag and other issues to land better. Plus to gain efficiency going up. Said holes on surface then could also be used as maneuvering thrusters.

Edit: If structural issues aren't a problem and it can actually fly is this a problem? Hydrogen embrittlement? I'm assuming an sto reusable concept might not like this.

Maybe a mix of fuels in that outside set of tanks that aren't on the cargo view. If it combines either kerolox or metholox and then has some extra lh2 for something maybe it can get away with less density. some of the cryogenics could be shared with the engines for enhance performances and then us different fuels or mixed fuels at different altitudes. Could you get away with an even mix of hydrolox, methalox, liquid oxygen?

Not sure about engine position and structure for the wings. But if you get it all in those last 6 tanks(3 each side) it would put all fuel in the body near some potential rear engines. Then just extra structure to the thick wings if possible... Then landing gear...

In fact, if I only used 6 tubes what would be the best fuel? Methalox?

That is 8246.68- 8482.3 ft3(1375-1413ft3 per tube) of room and 288,000 lbs minimum. If you can fit it in that space that is 10,042.6932 delta v at 950 isp.

And if any combo works you could have two go up in whatever configuration. One fuel the other and push it part way to lunar orbit then separate and return to earth while the other finishes the burn. And if needed it could always convert some tubes into more fuel tubes.

Edited January 23, 2022 by Arugela

[DDE]

5 hours ago, Arugela said:

Can liquid hydrogen be converted into a salt or similar form and reconverted for fuel to increase density?

https://en.m.wikipedia.org/wiki/Ayaks#Thermochemical_reactors

[kerbiloid]

MMH

[magnemoe]

As I understand one reason why hydrogen is popular for scramjets is that it burn fast and you don't have much time to burn the fuel inside an scramjet an added bonus is the cooling you get. 
However I say hydrogen has downsides for an warplane as its hard to handle and an orbital rocket can be much more optimized as it can have an long set up time. 

[kerbiloid]

6 hours ago, magnemoe said:

As I understand one reason why hydrogen is popular for scramjets is that it burn fast

Its high ISP due to the lowest possible molecular mass and its enormously huge heat capacity.
It can't be competed by any other coolant, and that's the case when the coolant is at same time  the fuel.

The historical HSHL SSTO projects of 1960s-70s include a plane with turbojets, a scramjet, and air scoops.

On start the spaceplane has its oxytanks empty, so weights much less. While the hydrotank is full.
It starts by turbojets using the hydrogen and atmospheric air.
Reaching several machs, it switches off the turbojets and engages the scramjet working on the hydrogen and atmospheric air, too.

It begins accelerating and slowly raising, taking air from scoops, liquifying it, and storing the oxygen in the oxytanks.
The lifting forse supports it, so it gets much heavier than on start.

It reaches the thin air altitude simultaneously with full oxytanks.
At the same time it starts feeding the engine with the extracted oxygen .

It closes the air intakes, and its hybrid scramjet is fed by the same hydrogen and the oxygen from tanks.

It reaches the orbit.

The hydrogen is used to cool both engine and hull.

[Arugela]

This is the max length you could get if you stopped the tanks at one side. I assume you want air intakes and or aerospikes at the end. Just about get the exact amount needed for hydrolox.

The 1x and 2x are how many are stacked on stop of each other. They make two triangles one in the butt of the other triangle like how the bomb bays are squished together.

NVM, that is the tonnage at 4.432 lb/ft3... I keep getting the math mixed up. You would need about 4.3 times this area.

The entire bomb bay and side additions are just enough to hold a little over 288000 lbs of hydrolox. My math was bad before. So, it would need to hold something much more dense.

those 6 side tanks hold a total of 7,557.76 for double that for both sides. 15,115.526 ft3 total for fuel in that configuration. That means I need a fuel that can hold 19 lb/f3.

If it was all in the body I would need 46 tanks for hydrolox. That means 46+36= 82 tubes at 72 ft.

I could do a pattern of 3+4+5+6+7+8+9+9+8+7+6+5+4+3. for 84 tanks and a bigger body.

Or change fuel types.

Again, if my math is right(normally not) I could do 2x3x2x1 from the center mass to get 16 total tanks on each side.

Would butane or kerosene work better? It's more dense in this case. I think..

Liquid kerosene would only require 4 extra tanks. It's probably better unless it's ISP is bad. Then it needs more fuel. That is 1 tank per XRS2200 or 2 tanks per RS2200. That might be the better fuel. As long as it's ISP isn't too low or other issues. It's the correct density.

Could you hold the lox in a smaller tank and keep it at crygenics temps in a closed cycle before releasing it for cooling and then keep kerolox at it's temp in bigger tanks. Then release the lox in orbit? Maybe save extra for cooling for a return trip? If you can replace lox as you use the kerolox maybe it would work out easy on the flight up? still not sure how much lox you would need.

pardon the messiness:

4xkerolox tubes+2xlox tubes.

You could even fill them both up within the 2000 ton limit. If the structure has a limit of 144,000lbs engines have 144,000 lbs. Kerolox a limit of 288,000 lbs. That leaves a 28,800lbs and 155200lbs left over from a max payload of mop bombs. So, you have a very large density of around 66lb/f3 for cargo.

This leaves 92 tons left over. This could fill another 2 fuel tank with lox almost perfectly. This leaves around 277,000 lbs of kerolox and 92 lox without even having to add to it during flight. Although you could to save fuel. And might to add a bit more effective kerolox efficiency. Hopefully I got the math right this time.

This means the bomb bay tubes are in a 1+2+3+4+5+6+6+5+4+3+2+1 setup. The 1+2+2+1 on the side are fuel tanks and the scramjets are behind them and air intakes in front if there is room for both. I'm assuming sadly near the wing edge. If this plane technically has a wing edge. I'm hoping the diamondish shape lends to making that a non issue. You could also change the size of the tanks and make them shorter and wider in order to compensate for the engine positions. Or move the engines to fit mid between them.

Assuming kerolox is 50lb/f3: 10ft diameter tanks, 36.67ft longx2. 1 per wing.

5x5xPix36.67x2x50=288,000lbs of kerolox.

That gives lot of room in front and back for engines and air intakes.

Lesson: 5ft diameter tubes are very inefficient for storage. Especially fuel.

 

Although a similar 10 ft diameter tube at 66 ft could hold 288,000 lbs of methalox. So, I guess it's a matter of choice..?!

do expandable 10ft diameter tubes exist for fuel? This could expand/contract for different fuels including filling it with oxygen later.

Still not sure if this would have to take off from water or need lots of landing gear. I would assume each has problems. One extra mass to float from boyancy needed 2 for wheel mass.

If it uses the anton 225's wheels it might need up to 50-54 pairs of wheels. 100-108 total.

Current max cargo is 1620 tons. This can be dropped to 1555.2 tons or 1440 tons for extra wight for landing gear and structural reinforcement. Max tonnage without cargo at 1440 tons cargo is then 560 tons plane weight. I'm assuming that would help with making it strong enough for good maintenance/reusability. It's also a potential wing loading of 144lb/f2. Not sure how the cubic wing loading would work out. Or what shape it should have.

If it can generate lox in flight is that useful for putting over the fuselage to control vortices and drag to increase aerodynamics and landing weight. It could land with lox seeping out it's pores. And possibly burn all fuels then use pure lox to deorbit if it has enough. Not sure if it would have a small amount of normal fuel for landings or subsonic flight or whatnot. And could lox be used to lower the speed and pressure along with intaken air of super and hypersonic flight speeds?

With 560 tons outside of cargo that is 144 tons fuel(methalox or kerolox), 144 tons structure, 108 tons landing gear(100*2160 lbs average each), 92 tons lox(if and when desired).

Another cargo config is 6x6x6x6x6x6 circles for 30x30x72ft. This makes a sqaure 1600sqft area or 64800 ft3. This simplifies the wheels to 12 per row. Or 12 per 5 ft. I think this gets 44,444to40,000 lbs per wheel pod. then divided by wheels.

Edited January 24, 2022 by Arugela

[kerbiloid]

ZAZ-968 "Zaporozhets", 1970s

Spoiler

Power ~45 HP (non-British, 736 W/HP) ~= 33 kW.

Fuel:  gasoline, consumption ~6 l / 100 km at 80 km/h speed, density ~= 0.75 kg/l,
so ~0.045 kg / km at speed 22.2 m/s.

So, effective thrust = 33 000 / 22.2 ~= 1.5 kN

Mass: 840 .. 1 160 kg, let it be average = 1 000 kg.

So, effective acceleration (in absense of road and air drag): 1 500 / 1 000 ~= 1.5 m/s².

Tank capacity: 40 l.

So, trip distance = 40 * 100 / 6  ~= 667 km.
Trip duration = 667 / 80 * 3 600 ~= 30 000 s.

Total delta-V = 30 000 * 1.5  ~= 45 km/s.

45 000 = Exhaust speed *ln (1000 / (1000 - 80))

Exhaust speed = 45 000  / ln (1000 / (1000 - 80)) ~= 45 000  / ln (1000 / (1000 - 80)) ~= 45 000 / 0.0834 ~= 540 km/s.

ISP = 540 000 / 9.81 ~= 55 000 s.

***

Once again.

Total delta-V ~= 45 km/s.

Exhaust speed ~= 540 km/s.

ISP ~= 55 000 s.

In Soviet Russia the cheapest cars were having ISP of a thermonuclear torch ship and were able to pass 1 AU in 40 days.
(Ok, in 80 days, as they needed fuel to brake.)

[magnemoe]

11 hours ago, kerbiloid said:

Its high ISP due to the lowest possible molecular mass and its enormously huge heat capacity.
It can't be competed by any other coolant, and that's the case when the coolant is at same time  the fuel.

The historical HSHL SSTO projects of 1960s-70s include a plane with turbojets, a scramjet, and air scoops.

On start the spaceplane has its oxytanks empty, so weights much less. While the hydrotank is full.
It starts by turbojets using the hydrogen and atmospheric air.
Reaching several machs, it switches off the turbojets and engages the scramjet working on the hydrogen and atmospheric air, too.

It begins accelerating and slowly raising, taking air from scoops, liquifying it, and storing the oxygen in the oxytanks.
The lifting forse supports it, so it gets much heavier than on start.

It reaches the thin air altitude simultaneously with full oxytanks.
At the same time it starts feeding the engine with the extracted oxygen .

It closes the air intakes, and its hybrid scramjet is fed by the same hydrogen and the oxygen from tanks.

It reaches the orbit.

The hydrogen is used to cool both engine and hull.

The questionable part here is to scavenge the oxygen in flight, that will require energy, granted you can use the cold hydrogen but wonder if its not better to run the turbojet on jet fuel and save on fuel tanks the liquefying equipment. 

[kerbiloid]

1 hour ago, magnemoe said:

The questionable part here is to scavenge the oxygen in flight, that will require energy, granted you can use the cold hydrogen but wonder if its not better to run the turbojet on jet fuel and save on fuel tanks the liquefying equipment. 

Who knows, but the projects were done by respectable companies, not on the back of the envelope.

So, probably of same possibility as Starship.

[Arugela]

I did give it enough weight for a full 92 tons of lox from takeoff. Maybe it could store enough fuel in a turbofan as part of the normal weight for the engines/aerospikes. If it can generate any lox it can help keep it topped off though. And maybe use it for the plane surface to improve aerodynamics. If it has enough energy maybe some cold plasma here and there if it helps. I would assume to cool the engines/help with surface drag or other things.

I don't think it can use hydrolox though. It would have to be enlarged quite a bit. I did the math wrong at first.

Is this possible: https://www.scientia.global/wp-content/uploads/Huu_Duc_Vo_Njuki_Mureithi/Huu_Duc_Vo_Njuki_Mureithi.pdf

I was hoping it and things like controlled air over the surface could help control things similarly. and if possibly intaking air like a bee to increase air flow to the engine to get a lower flight speed for super/hyper sonic. this might be a reason to use permanent magnets in a layer of the plane. I also though I saw a way to get electricity from them that didn't use moving parts. Not sure how much though. Would passing gasses help?

something odd like this applied to an air surface: https://www.windpowerengineering.com/dutch-wind-wheel-generates-electricity-without-moving-parts/

maybe these could be useful to pull air in via small holes in the wing or from other ducts? Before the air gets faster that is. Would it create too much drag to pull in air in smaller holes? can it help speed up the air in the main engine?

Edited January 24, 2022 by Arugela

[Shpaget]

8 hours ago, Arugela said:

this might be a reason to use permanent magnets in a layer of the plane

This makes no sense. 

Magnets in the RR video are a part of a brushless electric motor, and there certainly are moving parts.

Magnets are magic, but they still abide by laws of thermodynamics.

[kerbiloid]

They said. the copper is expensive in motors...

... until somebody suggested a motor based on neodymium magnets.

[Arugela]

What if the gas tanks have giant archimedis screws(or regular?) in them and they could be allowed to rotate when desired. They could be surrounded by permanent magnets to slowly rotate. Particularly as everything says you can't do high torque with them. Could this generate electricity? Would it help get rid of gas bubbles? They could be counter rotating on each side of the plane. When allowed to move they could generate electricity as the fuel is being used. 

What about a toroidal doughnut shape with two tanks? The inside and outside have a thin tank for lox for lubricant/friction control. The middle tank layer has the methalox. Then the farthest inside of the tube is the air tunnel for shock cone/scramjet? The inside of the methalox has a screw and the outside has permanent magnets and maybe so does the screw thread. When activated it rotates to generate electricity. The tank could be up to 20 ft wide.

Also I saw a permanent magnet turbofan somewhere also. Not sure if it worked or not. It was a defunct patent.

Could you put a permanent magnet based turbofan in the front of the plane behind the air inlets/shockcone to balance the aircraft weight out. Assuming where it needs to go physically?

That or put it inside part of the toroidal shaft where it balances properly on the craft. Not sure what you do about the cold/hot regions next to the lox/methalox tanks. Could this be used to help create flow? And is trying to cool superflow air helpful for ram/scramjets or harmful? Would cold plasma being pumped into the aircraft air stream help at all? If not also in the body automatically when the tanks rotate?

The giant tanks could be part of the air/turbojet/air intake system. would that be hard to cool properly or could it be useful or at least used for something?

I just read heating the air reduces power. So, if you super chill it and put the permanent magnet tuborfan at the back or just lived with the heating of the tank that could increase the gas expansion along the path creating more airflow and then activate it at an early speed? Then the toroidal shape could be part of the air intake system.

could you simplify the cryogenics by then only needing to cool the lox and then leave the temperature difference naturally for the methalox via the shape of the tank?

At that point I still wonder if the tanks/engines could be balance to leave a diamond shape airframe or if the wings would be needed to be brought back a bit to leave the com ahead of the col. I imagine you could design the tanks to be forward a bit to balance on empty. They would probably be heavy in themselves.

cool sound too:https://www.youtube.com/watch?v=rHvpcqj4XB8

I wonder if you could use the cyrotanks to cool it enough for the mangets to work.

https://cen.acs.org/energy/fossil-fuels/Cool-fuel-hypersonic-aircraft/96/i18

Also, could the concept of a sterling engine be used to produce electricity from the hot side? Some Lox could be pumped in if it's safe enough. If cold plasma is to be used it might need a lot of electricity. I haven't found how much can be generated in general yet.

Edited January 25, 2022 by Arugela

[Shpaget]

Can you please pick one concept and refine it instead of just throwing a random though out there and moving on to something completely different in a same sentence?

Please forget about magnets. They are not a source of energy, no matter how cold you make them, nor will they make an Archimedes screw rotate.

Don't concern yourself with COM and COL. You're not designing a spacecraft. Figure out the fundamental physics and basic concept of your ideas first.

[Arugela]

Or  you could learn the concept and not be bothered by it(or god forbid share.). You're not exactly adding to the conversation and It's not my fault the information to learn anything is so bad. Particularly because of people like you. I'm not paying 10's of thousands of dollars to learn something. And if you hadn't noticed all information on the internet and otherwise has been reduced to make people reliant on colleges on purpose. So take your complaining elsewhere.

I'll simplify something for you. Correct answers are just all the information. If it's not present or impossible to find people cannot and will not learn something(particularly when certain layers are constantly missing. Or data is very heavily specialized and no middle info is available.). The real world measure is if they did or didn't. At this point it doesn't exist. And this info is only complicated because of the lack of translation and ability to do so over the giant mess that is the modern internet/libraries and other sources. That is how the real world works. If you can't  find the info and layers are missing or too messy it's not reasonable and destroys how many people can and do learn things. We're not in a remotely reasonable environment. There are practical things that must be done for others to learn.

BTW, aerodynamics isn't complicated fundamentally. It's because of the mess of information and how hard it is to find info and other issues. It always has been. Although previously we had the difficulty of going to places to get info in a less than ideal manner.

if you translate and supply information most subjects are absurdly simple.(basic proper writing and definitions. Not relying/overrelying on third party info etc. Not adding unneeded wording.) Most modern issues have to do with nothing else. It's also why things don't advance as far. If you hadn't noticed we are getting ever increasing childish egotistical issues in science and similar areas for decades now. This is why. It's the lack of surrounding data from more people learning the subject in an inefficient setup. If the data were better and people could learn it reasonably this would all change and there would be more to go against and more learned overall.

I'm so sorry I'm looking at it from an engineering standpoint and exploring. But those areas have no information on it. I figured you guys are so knowledgeable it would be trivial in a conversation.

You noticed how in real world applications you usually want to keep large data on everything. You want that or a equivalent in information available for simple translation amongst other things. Just like before we messed up the computer world. anything is possible if you have sufficient documentation to bridge it. Most science area's are ultra focused. That is bad for learning or broadly learning and leads to lot's of problems. It destroys bridging information. Then followed up by the other problem with expecting everyone to know something because someone else does. Without any real world understanding of how that happens or what must be there it to exist. Especially when those people have areas heavily done and formatted for them and learned in a specialized manner. People all come from different starting points. What you need is the info from different point to all get to the same points. But broadly enough to cover all subjects. We have that distinctly missing or culled currently for personal gain and other childish reasons.

This is the same fundamental reason colleges can't translate credits between them efficiently. That, btw, should not exist as a problem. That is from a fundamental reduction in education standards that should no way exist. It should literally void all degrees attached to the problem. The ability to do that is literally the basis of the standard for education naturally...

Lets see if you can be useful. Find me a source of actual data of weight and tolerances of real world aircraft landing gear models. I can't find any.

And this for increased lift. The entire body could have it withing the unused parts going to the edge. And partially closed off to the direct it to the engine for inceased performanced potentially: (during takeoff and landing likely.)

It would be adjustable. And when closed it would be a single solid air frame wing that is symmetrical. Probably held in the wing itself. like a closable air intake. Or something else if possible.

If you are putting lox outside the plane could you use it and or methalox to make the entire plane body into giant aerospike and fly into orbit like a flaming pheonix? Originally I was wondering if the lox would help lower air surface temps. But if you can just use it like a giant engine... The entire plane could get a boost of speed at the top to get into orbit faster with the entire body of the aircraft. That would be a possible advantage to making the plane body like a giant aerospike diamond. And a reason to carry up all of that lox with you. If you mixed it with methalox over a much larger surface! AND THE ENTIRE PLANE WAS AN AEROSPIKE!! 8D

It's the perfect solution. None of the plane is wasted. And the low lift of the plane is made up for in raw thrust! Just need some temp controls and whatever structural issues! 8)

And the wheels might need to be based on quad weight tolerances(or more) instead of double. That might be easily possible though with the numbers. This is in case the aircraft leans sideways. But not sure how to figure that out.

Edited January 25, 2022 by Arugela

[Shpaget]

13 hours ago, Arugela said:

Or  you could learn the concept and not be bothered by it(or god forbid share.). You're not exactly adding to the conversation and It's not my fault the information to learn anything is so bad. Particularly because of people like you. I'm not paying 10's of thousands of dollars to learn something. And if you hadn't noticed all information on the internet and otherwise has been reduced to make people reliant on colleges on purpose. So take your complaining elsewhere.

I am trying to add to conversation by pointing out flaws in your concepts. If you don't want criticism, just say so and I'll add a little clap at the end of my post. You don't need 10s of thousands of dollars to access information and learn. I don't know where you live, but libraries are free, or next to free in  most of the world. Internet is full of free courses on every topic imaginable. If you want to read a scientific article that is behind a paywall of a journal, just email the author and in 9 out of 10 cases they'll happily send you the article for free. I'm not sure what complaining you are referring to, but I'm not doing any of that.

13 hours ago, Arugela said:

I'll simplify something for you. Correct answers are just all the information. If it's not present or impossible to find people cannot and will not learn something(particularly when certain layers are constantly missing. Or data is very heavily specialized and no middle info is available.). The real world measure is if they did or didn't. At this point it doesn't exist. And this info is only complicated because of the lack of translation and ability to do so over the giant mess that is the modern internet/libraries and other sources. That is how the real world works. If you can't  find the info and layers are missing or too messy it's not reasonable and destroys how many people can and do learn things. We're not in a remotely reasonable environment. There are practical things that must be done for others to learn.

It is impossible to categorize and neatly organize every bit of obscure information available. It is entirely reasonable that for some specialized info you need a little bit more than a single google search. Do some legwork.

It is also unreasonable to expect every bit of information to be available in a perfect translation to every language. Someones inability to understand the language of the author is not authors fault, nor is it the responsibility of the author to provide every possible translation.

13 hours ago, Arugela said:

BTW, aerodynamics isn't complicated fundamentally. It's because of the mess of information and how hard it is to find info and other issues. It always has been. Although previously we had the difficulty of going to places to get info in a less than ideal manner.

Yeah, I'm gonna disagree on this one.

13 hours ago, Arugela said:

Lets see if you can be useful. Find me a source of actual data of weight and tolerances of real world aircraft landing gear models. I can't find any.

I managed. It took me about 15 minutes. This is for 747-400, hope it suits your needs.

https://moam.info/d043u544-gpr1-747-412-4h6_59beb58d1723dd45281d4de0.html

Search for 1-86-041 and 1-86-051

13 hours ago, Arugela said:

And this for increased lift. The entire body could have it withing the unused parts going to the edge. And partially closed off to the direct it to the engine for inceased performanced potentially: (during takeoff and landing likely.)

You're talking about a scramjet and post a video about wing configuration specifically designed for ultra-slow flight. I don't see a connection.

Increasing lift is not free. It comes at a cost of drag.

[Arugela]

You realize all the data charts were removed from that link. It literally has no info. And if that bottom info is it it's unreadable.

The wing idea was for landing/takeoff. The idea would be to open the front/back of the wing, or some other transformable wing, give it a similar config for takeoff for life, then close it back up for normal flight if possible. It's just an idea. It's giving a semi statick ability that birds have in a normal craft. Plus giving the craft one of it's most needed qualities. This could be combined with funneling air into the intakes for extra low super/hypercruise potentially. It might just need to be designed well enough to not create too much drag. I would assume it's only used at important point to get air speed up. It would have to be adjustable enough for different uses. Open for that air wing configuration. Closed with a different shape for getting extra air to start super cruise early. Particularly since the wing isn't being used much.

BTW, I used to look this stuff up for fun a long time ago. It was very easy to find very detailed info on every part of something like landing gear worked. Tolerances for every part, material, etc. All heavily condensed into single sources and easy to read or study if you desired. This is getting ridiculous.

All I'm finding on any subject, besides a few documents I don't now enough to read, are very rare occasional to a single weight or piece of info that is not enough to do much of anything with. It doesn't matter what the subject is either.

Edited January 25, 2022 by Arugela

[Shpaget]

I wouldn't have posted it if it didn't contain the data. If you can't see it, there is something wrong with your computer.

This is a screenshot of one of the relevant pages.

 

[Arugela]

Yea, some of it is showing up now. Not sure why it was blank for so long. Must have been loading very slowly...(like part of a day)

Here is the patent I found: https://patents.google.com/patent/US20160377029A1/en

What about an obscene 13 wheel landing gear.

It's a normal 2x2 but doubled. The middle has a nother 2x2 on each side on the outside. That is 12. The 13th is in the middle and is a stearing wheel.

If you only count 12 as weight supporting then, if it weight the same as the other one plus extra tires approximately, 9000lbs per wheel? If so you can get a 12 wheel x12 x2. I guess a double 4 setup with a front steering wheel might be easier if it helps to have stearing. easier to acount for the mass of the cargo(8000lbs for 8 wheels.). Outside of the body weight.

Trying to read this, but going with my aerospike wing idea: https://link.springer.com/chapter/10.1007/978-3-540-85181-3_83

Edit: I'm starting to wonder if the problem is google... I have a tendency to open up to 100 tabs(or more) when I play games searching for info. I think I've had this happen in the past. The moment an external link is introduced from someone else(or several) magically the same search results start flooding real information. Before this I'm literally going insane trying to find information and getting nothing.  I wonder if their search logarithms are being flooded by this sort of activity. And the info being searched from another persons external source is adding data for it to finally show other websites. I'm betting their search/display logic has some sort of limit or focus problem. Maybe too many youtube videos also... Since they own youtube I wonder if it effects google searches.

Trying to read this, but going with my aerospike wing idea I might be in the right direction: https://link.springer.com/chapter/10.1007/978-3-540-85181-3_83

Just the wrong type of aerospike. 8\ Wonder how light weight it is. You could being them out of the body on demand for certain parts of flight. Maybe they could be made to auto adjust as needed or as is efficient somehow in a simplistic reactive way that doesn't create too much extra drag. I'm assuming my wing being symmetrical, and potentially designed to fly upside down, might want these on top and bottom.

Apparently this isn't new: https://www.hindawi.com/journals/ijae/2021/9370331/

Could these be made of that niobium metal for going to orbit?

Could these be put in a scramjets air flow to help light it?

I found the thrust to weight of the xrs2200 and rs2200. 35 and 80. so 800,000 thrust is only 11-12 tons no matter what. That is fairly light. So, that could go in the engine or fuselage weight.

Edit2: I also forgot to apparently multiply by ln. I was working with much larger delta v. I was doing 900x9.81x1.0776 instead of ln(1.0776)*9.81*900.... Unless scramjets and whatnot can be that efficient on the way up. 8\

I think it can still get to orbit, but it needs a good chunk of the cargo to do so. Have to refigure this now.

If I give it around 844 tons of more methane(assuming you can run it on methane) and near 596 tons of cargo it might be able to make it. So, maybe a 0.3 cargo ratio. similar to the shuttle. But it might need to take off more tonnage for fuel and structure. This assume 1450 average isp from the scramjets and 450 average isp for the aerospikes.(along with 9550 Dv to fully circularize orbit and not just get apoapsis up.) The fuel would fit in 2 24 ft diameter fuel tanks at 72 ft long. Might have to be specially shaped or some fuel in the wings. But this would have the benefit of more cryogen in the ship to cooling to the surface.

No idea on the other cost. But it is near the same values as the shuttle in some ways. I think it's main point would be for ultra dense cargo.(mainly because the original design is from a bomber for moab/mop bombs) Unless a larger version is made.

For less dense cargo it would need it's bigger version at around 288ftx144ft and use liquid hydrogen. That might give room for a larger cargo bay. No idea on the cargo size though.

Can you convert a ge9x engine into a ram/scramjet and only use the rear smaller diameter? if you could fit at 1.5meters diameter at 4x on each side and 110,000lb thrust they would be usable for takeoff. Assuming I'm not missing anything else. If it could be brought down to 18,000lbs per engine instead of 21,000 it would be perfect. The rest of the engine could be in the other weight categories as It's using methalox cryogen to cool around the air intake. Assuming you can do that.

From what I'm reading, the proper compression ratio for ramjet is around 60 and scramjet between 50 and 100... The ge9x is around 61:1.

Maybe not. I did it with more detailed scramjet info(I think.). It might be able to get 236-308 tons to orbit. Depending on the engine weight. If it does 288 tons to orbit then that leave 20 tons for scramjet/ramjets without a turboprop.

If it went up to 1.2 mach with aerospikes:

0-1.2mach: 200t fuel(118+82t) (isp360) 411.6dv? aerospike

1.2-5mach: 68t fuel (isp 3450) 1303.4dv? Ramjet:methalox+air

5-15mach: 288t fuel(ISP 2160-1900) 3430dv? scramjet: methalox+air?

to orbit: 884t fuel (isp 450) 4255dv? aerospike.

Edit3:

Mach15-25: 262t+182t 444t (isp950) LM+LOX1444-1000(3430dv)scramjet+lox
mach25-orbit: 98t+68t 166.66t (isp450) 1000-833.333(825dv) aerospike

This uses 833t methalox and 333t lox.

^If this works and the engine weight without turboprops is light enough it might get the full 560t cargo. This gives 560t cargo with 1166t of fuel. this gives 20-22 tons for aero forces for extra fuel and if ram/scram need more weight or other issues. Not sure if turboprops could add more efficiency to the start of the flight or not. Or if any of the above is even correct.

If I'm correct the wing weight and body weight are the same at max load. around 583/560/583 with the center more conventrated and the wings distributing the weight more on the sides and with more structure in the center and body where needed. Optimal distribution might be 666.66/666.66/666.66. The fuel would take up any space not used. Not sure how the fuel loads change over time with lower loads.

With fuel cost alone that is 5 dollars per lb of cargo. and you could run tickets for 1728 persons, if they can fit, at near 3-5k a seat! 8) 5k making around 3.3million per flight above fuel costs. Fuel cost 5.25 million per flight at full load. Not sure how much fuel for a people run. That is about less than halve the tonnage, not including seats and other things. So maybe half the tonnage. If fuel is halved for half cargo then you could have bare minimum seats cost 1500 per person for a 1728 person flight. I'm assuming that doesn't work that way with fuel though.

Edit4: And I forgot to half the cubic area so unless you fly a wing that has a blunt or very rounded edge along the front/back it has a lot less space and must run on kerosene. Not sure how to do that one. If you could make the front fat and round enough to make up for the thin back and not loose volume for fuel you might be able to run on methane. If not kerosene. Unless I just did all the math wront... I hate math. Nope, it has around 72,000 cubft to use and I thought it had 144,000. This means it can't hold the methane fuel. It needs more dense. by about 2x. Or more interesting combinations.

This can probably be done better for more cargo space. But as is it might allow 288t cargo. If not it might be able to get up to the 560t stated before with more details. Especially the scramjet to mach 25 part.

This is then down to 0.144 cargo ratio. So, unless it's cheaper it's worse than the shuttle. And airfriction not accounted for could take the entire cargo away. So, a 2 ton maybe reusable ship for a few crew members and if lucky a few 100 tons of cargo at most. Unless my math is still that far off in a good way. Probably not since I used what were probably hydrogen ISP values and not methane! 8) So, goodbye cargo! 2000 ton 2 passenger plane to orbit! Maybe. Not to mention structural weight hasn't been gone over. I bet it's heavier than expected. Maybe a bigger plane with more weight and bigger wing. Then hydrogen and maybe some less dense cargo. Maybe 3600t to orbit!

When you figure delta v and tonnage for a fuel and need the 200tonnage for delta v to get to 411.6 velocity. If you use the ISP of the fuel do you add the oxidizer to that weight or can you simply divide by the fuel ratio within that tonnage?

I was doing 2.5lox-3.6lmethane. I took 200/6.1 and multiplied each number to get the total of each fuel. Is that mistaken? 82lox-118lmethane.

Does anyone know the answer to this also: https://chemistry.stackexchange.com/questions/111355/can-a-stoichiometric-mixture-of-oxygen-and-methane-exist-as-a-liquid-at-standard

https://space.stackexchange.com/questions/34973/pre-mixing-cryogenic-fuels-and-using-only-one-fuel-tank

Quote

particularly as JPL later demonstrated that you could make the mixture detonate merely by shining a bright light on it

So, ignition source is dependent on time of day! 8)

This has nice stuff in it: https://www.sto.nato.int/publications/_layouts/mobile/view.aspx?List=44a8f49d-e481-458a-91b4-212a9605bd9e&View=b927897e-9dc2-4392-aa25-598b0c04b48e&RootFolder=%2Fpublications%2FSTO Educational Notes%2FRTO-EN-AVT-150

Including an als (air liquification system).

https://en.wikipedia.org/wiki/Air-augmented_rocket

https://en.wikipedia.org/wiki/Liquid_air_cycle_engine

maybe a sabre engine that liquifies the air for use at the upper stages of flight so it starts with empty tanks and the lox/lair for closed cycle. And with a scramjet attached.

I wonder if you could get 2x sabers on the bottom and 2 on the top and use the body shape to get the less angled air filled. then the engine weight could be centered.

With 4 sabre engine, pulling hydrogen and lox out of the air, and a scramjet you might be able to make it work.  You would need your hydrogen to produce a decent amount of more hydrogen though. Maybe from water and use the remains. The liberally projected 198tons of hydrogen takes up around 83,000ft3 and the ship is only around 71,200ft3. So, it needs something to make a lot of hydrogen. Or a bigger design. Or a different fuel. Liquid kerosene might work with the design and some engine configuration.

Edit5: Actually I have 96,480ft3. So, I have enough to carry all of the 70kft3 needed for fuel(assuming any of my delta v is correct.). Anything generating oxygen can reduce this more and get more volume for cargo. So, the older methane with aerospikes and just ram/scram and no props might work if that is possible to begin with. And technically the hydrogen might work also if it can be efficient enough, but with even less cargo space and value. Or is the 96480 per side of the aircraft. If it is then hydrogen is on the table.

 

I'm bad at geometry:

Is the volume of the ship: (83.75*96*36)/3 = 96,480x2=192,960ft3? <- this is half of the ship as a 3d triangle. NVM, I took 96/36=2.666666 and divided further for approx 72kft3. That makes more sense. That formula I'm guessing only works for a sqaure. So, back to kerosene or a change in body design.

http://www.astronautix.com/l/l-1linearaeospikebooster.html

I'm hoping this means it can run on it.

 

Part of my original idea might be good. If I make it fly omnidirectionally with sc/ramjets facing towards the 60degree angle and the other engines towards the 120 degree angle or something. It can use both edges for a nose. This may help it in supersonic flight. Maybe it can be designed to slowly yaw sideways towards the other nose as it activates the ramjets. Maybe a spherical middle area with fuel tanks and engines and the body rotates around it. Or at least giant spherical gas tanks inside.

https://space.stackexchange.com/questions/43677/is-it-correct-that-the-saturn-v-rp1-tank-was-pressurized-by-high-pressure-helium

I assume it would help with ominidirectional pressure release.

 

 

Edit6: (bingo!)New rotating ship. If my new math is correct I have 192,000ft3 to play with(maybe 172,000ft3?) and not 72k. This means  pure hydrogen(maybe methane/lox if it can get to mars) and a massive tank in the middle. This ships points is to start at a 120 degree angle and slowly turn towards to 60 degree angle as you increase mach speed. If it can get liquid air/lox all the way up to mach 25 it only needs a tank of 168 tons of hydrogen(52.5105984 ft diameter, 75812.27ft3) to start until it hits space and then fills(or already has filled) a middle tank inside with lox/Lair for the final boost. This means a max takeoff weight of 2160 tons. 8 sabre engines(body rotates, but tank/engines stay in the same direction as body rotates around them.) and double landing gear top and bottom. Not sure where to put them.

 

The front angle is exactly 120 degrees. The side angle exactly 60 degrees. The top side angle is almost exactly 114 degrees and the side side angle is almost exactly 66 degrees. It has exactly 192,000ft3 of room. A little more with the sphere's popping out of the body. Not sure if it helps to have that exact of a number for the angle. If it does I could dop to exactly because of the extra ft3 from the sphere's sticking out.

 

Specs:

Dimensions: 166.27x96x54.0266ft(sphere 57.6 ft diameter(body angling from 54.0266ft.)

Cargo: 1440tons (passengers 800+?)

Max takeoff weight: 2160 tons (2000 nonimally.)

Engines: 168 sabre engines (with scramjet abilities added to mach 25.)

fuel tank: 52.5105984 54.02663253650301115974ft diameter sphere(inner diameter)(up to 54ft diameter(57.6)), 168(182tons max(222)) tons of LH2 max(has an inner tank that expands to hold Liquid air or lox as needed. Or some equivilant.)

Crew bubbles: 14.4ft diameter

Passenger bubbles: 28.8 ft diameter

Tonnages:

Cargo: 1440t

Landing gear: 162 tons (50 pairs of 4x wheels?) 120tons(36-37x4)

Fuselage: 144 tons

Engines: 192 96 tons (168xsabre engines, /w scramjet/las?) (up to 12? for twr 1.25 and up.) 8 engines is 1.1 or less than 1 on takeoff. May need 2.0 thrust to not overuse fuel. 16 engines or less if new ones with sufficient thrust exist.

Fuel: 182.9tons LH2 (multifunctioning tank.)(54.02663253650301115974ft diameter, 82,570ft3) 21 tons dry weight?

 

So, now it's a matter of how bad my math is for the fuel usage. And structural issues... (including landing gear placement. maybe water/landing takeoff and fuel up in the water for free to fill hydrogen?)

 

The middle tank would be attached to a plate on the surface that holds the engines. This can rotate. Or the body can rotate around it. This gives dynamic life/aerodynamics and the ability to rotate the engines to any combination for entry or other situations.

 

It would be a little like the interdictor from star wars, but with the bubble in the middle and two side bubbles.

 

It may needs lots of liquid oxidizer and go way above the normal weight for flight. I wonder if the cargo bays could be used as duel tank for oxidizer without harming them.  Depending one how aggresively it can get or convert lox/ liquid air.

 

Is there a way to recollect some of the vapor water/ break it back down, then use the oxidizer over again to reduce the needed mass and never go over the max ship weight? If you run at 8:1 ratio and some of it is recollected like it were at 6:1 could this save on oxidizer somehow. The last stage has to go up to 2500 tons if it can't collect/recycle. any reuse might be helpful to add to collection and have more on hand at any moment, even if it adds inefficiencies. The ship has enough storage room for oxidizer, but the weight of it makes the hydrogen use too inneficient and increases it beyond the tank limit potentially. If not close(assuming my math is close to correct.) any effective increase in oxidizer without adding more mass at any given moment would help. could the bell nozzles lap any of it up the sides like a reverse regenerative cooler. Or literally with the regenerative cooling system? If it goes back in the hole like a reverse film cooling it could be broken back down and shot out again hypothetically. Or just shot out as water and steam as an additive if it gains enough efficiency or acts as an oxidizer. The objective is oxidizer at all costs. Not sure how much could be collected at that point. A little bit of hydrogen wouldn't hurt either. Else cargo tonnage has to be reduced. Which is probably ok.

 

So, would a recycling, regenerative, (reverse?)film cooling be possible? The point would be to reuse some of the oxidizer or water forming and keep reusing it as oxidier in effect or something similar. Could you lap water back up the engine wall like water up a spoon? Maybe on the outside of the nozzle?

 

https://www.quora.com/How-much-water-does-it-take-to-put-a-rocket-into-space-using-hydrogen-and-oxygen

 

 

That is a lot of water to collect by the looks of it.

 

If anything maybe a low thrust space rocket variation that recycles the lost water on purpose. Or is that less efficient?

Actually that would be the most beneficial thing. The lack of needed oxidizer during orbital circularization burn would save the most mass and problems.

 

Here are my guesses as to performance.

Did I use delta v in KM/s or similar vs lb's? And does that change the end answer? I'm almost wondering if it's odd odd this is actually almost working. I think I was thinking Delta V was a neutral term. Yep, I used m/s as delta v.

 

If I can ever get my brain to do the conversion properly maybe it can do methane or kerosene still.. I think I correctly found I have near 172kft3. So, I have the volume to work with now... 8\ I was previously using the cross lengths to determine volume. I think I found the side lengths are about 55.6 ft in all directsion. Could still be wrong. I'm getting worse at math by the year. 55.6x55.6x83.13/3 = 85,661.585ft3x2= 171,323.1712ft3 for both sides. Still not sure that is correct though.

 

I'm very unused to metric. It will take a while for my brain to figure out how to convert it fully.  As simple as this technically is.

 

Here is a new chart. 8 hour flights to orbit with only 8 engines:

 

 

This design has 1440 tons cargo.

360 tons structural: 96tons(engines), 144 structure, 120tons landing gear.

360 tons fuel maximum: single 54ft diameter tank with 182.7 tons lh2 and enough weight for lox/lair to be added in flight.

Max weight around 2160. Normal takeoff weight around or under 2000 tons. last burn in space would be 2160 tons with 360 split between needed hydrogen and oxidizer.

 

As long as isp is neutral and doesn't need to be converted to ft/s this is a potentially feasible design. The only thing I haven't gone over in detail is the structural issues. At least from a superficial standpoint.

 

The main problem may be I used 8:1 ratio and if it can't go that hot it may not have enough fuel in the 182 tons if using 6:1 ratio or less. I was hoping this could be relatively solved by the engines being mounted to the giant cryogenic tank holding the hydrogen.

 

If you filled the center tank with a mix of lox and methane it could get over 6000 delta v with 360 tons of cargo and 360 tons of ship.

 

New messier version with optional positions and exact angles:

 

Still trying to figure out the correct isp at 8:1 ration, but can you run  8:1 if enough cooling could be produced and use liquid air's extra bits to provide higher isp? It would save huge amounts of tank space. If not I have to largely increase the tank size potentially. Though probably not too much because of the volume increase with a sphere. I was also hoping to over pressurize the hydrogen. Assuming it can go past the 4.432 I think I saw for the mass/ft3 I saw for the shuttle. I haven't gotten far enough to figure out how this works yet to work out the details.

 

Wild assumption here, but if I went with the flying aerospike idea could the thrust being pushed off the body of the aircraft like an aerospike help with cooling?

 

https://news.brown.edu/articles/2015/07/melting

 

Maybe this. My hypothetical material heat limit is for 4420 K. Just because it's the value for compressed hydrogen.

 

Could excess liquid air be stored to raise ISP by allowing the engines to fire into an artificial atmosphere at the end of the jet nozzle. Hopefully allow more heat to be outside of the engine and not inside. I assume by letting it out at the end of the nozzle and like if it were regenerative cooling released at the end of the cycle. It's probably excessive, but an ISP of 1200 past mach 15 and in deep space would be an interesting goal. How much liquid oxygen would need to be released to burn into if that is effecting ISP and not thrust.

 

So far my design, probably not realistic, stores 82,570 ft3 of space for hydrogen. If it has a lining to store the hydrogen that shrinks and then fills the outside with liquid air(or the reverse), if the liquid air is the same as lox, then that is 71.2 density per ft3 filling in afterwards. That maxes at under 3000tons(just under 2250 tons if lair is 54.3123/ft3.). So, there is lots of room. The hydrogen can only get around 183 tons of liquid and 218 tons of slush.

Edited February 26, 2022 by Arugela