F-14 Space Launch Vehicle

Originally posted by esecallum
no.

you are deliberately lying...just imagine a 747 going into a vertical postion and it collapsing.

And this is where I no longer care about you.

i challenge you to quote me a single instance of this collapse happening...

I certainly can quote you many instances of a 747 reaching ultimate load and as a result having structural failure, but there are a few things stopping me (in order):

1. you will reject anything I put forward

2. from your posts here, its obvious you wont understand the accident reports and the technical terms they use

3. you quite obviously dont want to believe anything but your own misguided views about physics and aviation

4. because of the first three points, it would be a waste of my time to spend 10 or 15 minutes compiling the information in a post.

So, please feel free to continue with your ludicrous plan, and we will continue to laugh at you.

Originally posted by waynos
But you DO want to slow down when you are coming back, which is what was meant by the question.

Yes that was what I meant! I didn't think it was that hard to understand, especially since I have asked it twice already to no avail!

Esecallum, you have to slow the plane down before it reachs the atmosphere on its return journey or it would be ripped apart. Thats assuming it could make the outbound journey of course, which it cant.

esecallum, all the other posters in this thread - waynos, jra, RichardPrice, and gfad in particular - have been letting you get away with a lot. It is considered "good form" to back up claims of any kind with evidence, like links to other web sites, reasonably detailed technical explanations, and (where appropriate) mathematical calculations. You have provided none of this, apart from from some mis-understood and/or misapplied calculations.

So, how about some links? Can you give us a detailed technical explanation of how the engines on your orbital 747 will work, or maybe calculate how much fuel/oxidizer you expect they will require? How about explaining how you expect that a 747's wings will still be producing lift when accelerating upward at a 45-degree angle?

Or how about just answering the question about how you plan to slow your plane down when you want to re-enter the Earth's atmosphere?

Of course, I doubt you'll do any of those things, because if you do you'll find out exactly how crazy this idea is.

Originally posted by gfad

Originally posted by waynos
But you DO want to slow down when you are coming back, which is what was meant by the question.

WELL ASK MORE CLEARLY.


its very simple ...you rotate the plane 180 degrees slow to 500 mph above 100 km above the earth surface then re-enter the atmosphere...

then rotate again 180 for forward flight...

no heat shields...no stresses.


so to summarise

from 0 to 100 km height you take-off and travel at an angle of 45 degrees upwards at a speed of 500 mph.....

lift being provided by both engines and wings...

you will reach 100 km or 70 miles in under 20 minutes


at 100 km zero atmosphere =zero drag=zero friction and you will reach 7800 metre/second at 23000 miles high very quickly...

Originally posted by PhloydPhan
esecallum back up claims of any kind with evidence, like links to other web sites, reasonably detailed technical explanations, and (where appropriate) mathematical calculations.
.

if you bother to look and read i have already done this...yet you have ignored them and tried to villify me instead...

i have answered every question at length..just look at the size of my responses to every question...in depth and very detailed...


admit it...you are just jelous and do not want other people to succeed because

Originally posted by esecallum
i have answered every question at length..just look at the size of my responses to every question...in depth and very detailed...

Size of ones reply is unimportant, its what's in it counts. I could write a dozen paragraphs of nothing but 'fluff' if I were so inclined.

You are not going into this very detailed at all. One major thing you seem to skip over constantly is the amount of fuel one would need. How much fuel is it going to take to get up to 7.8km/s? (a lot I'd imagine) and then you're going to need just as much to slow yourself down again. It sounds highly unlikely that a 747 could carry enough to do all that.

admit it...you are just jelous and do not want other people to succeed because

No offense, but how old are you?

Originally posted by esecallum

its very simple ...you rotate the plane 180 degrees slow to 500 mph above 100 km above the earth surface then re-enter the atmosphere...

then rotate again 180 for forward flight...

no heat shields...no stresses.

No heat shield, no stress (ignoring it getting to orbit in the first place) - but lots and lots of fuel and oxidiser required. Which the 747 cannot carry.

Put simply, the Space Shuttle doesnt use a heat shield for fun, it uses it because it cannot carry the required fuel for deceleration so it uses the earths atmosphere.

As I said in a previous post, the Shuttle takes over four times the fuel load of a 747 to get to orbit, and it also uses a fuel mixture with a much much higher specific impulse - meaning the 747 would have to carry a lot more than 4 times the fuel load to achieve the same effect, but we shall ignore that for now.

But also as I said earlier, its a lot more complicated, as the operational empty weight of a 747-400 (ie no fuel on the 747) is over twice that of a Shuttle with payload (ie no fuel on the Shuttle). So we are now talking at least 8 times the fuel load of a typical 747 - which puts the 747 well above its maximum takeoff weight, infact it puts the aircraft well into the region of danger just with that much weight onboard and sat on the tarmac.


The Shuttle uses 2 million litres of fuel and oxidiser (excluding the solid fuel boosters), and the 747 idea would require 4 million litres to get it to orbit (discounting the other problems with your idea).

But now you need to get it home safely without a heat shield, and the law of conservation says you need the same energy to do this so again we are talking another 4 million litres of fuel.

8 million litres of fuel on an airframe designed to handle 250,000 litres maximum.

Assuming the fuel density gives a per litre weight of 0.5kg (it doesnt, all Jet A is heavier per litre, nearly a kg), that puts the fuel load at 4 million kg.

4 million kg for fuel alone on an airframe designed with a maximum takeoff weight of 440,000kg on the newest, largest model the 747-8 (which has the same fuel capacity of the -400).

Yup, theres flaws in your arguement all right.

Originally posted by esecallum
WELL ASK MORE CLEARLY.

its very simple ...you rotate the plane 180 degrees slow to 500 mph above 100 km above the earth surface then re-enter the atmosphere...

then rotate again 180 for forward flight...

no heat shields...no stresses.

Well I think I did ask pretty clearly the first time!! :

Originally posted by gfad
A 747 won't break the speed of sound with out falling apart first. I know what you are going to say ... but there is no resistance so it is ok. Even if that was true how are you going to slow it down again before it reenters the atmosphere? If you dont slow it down it will just be ripped apart at about 400,000 feet when it starts to hit the atmosphere.

and then again:

Originally posted by gfad
Esecallum, you still havn't answered my question above about how you are going to slow the 747 down from mach 3 or whatever before it reachs 400,000 feet.

Secondly how do you propose turning the plane 180 degrees? Thirdly I think you will find that an engine operating on a wing that is travelling at mach 5 in the opposite direction is going to provide just a bit of stress on the wing, otherwise how is it going to slow it down?! I know 747 wings are built to deal with these stresses.

WELL ASK MORE CLEARLY.

Well, it must have been pretty clear already because it was gfads question, not mine, but I had no trouble understanding it.

its very simple ...you rotate the plane 180 degrees slow to 500 mph above 100 km above the earth surface then re-enter the atmosphere...

Thats what I was afraid you'd think. In this entire mad scheme that has to be the maddest part yet.

The sad thing is you shouldn't need a detailed explanation of why that is just so completely wrong, common sense should be enough.

I've been watching this thread for a few days now for amusement and I must say I think esecallum is having a little fun with everybody. IMO he's just trying to irritate. Call it techno-trolling.

Oh, by the way... I had this idea to turn a Winnebago into a submarine. Anybody interested?

Originally posted by esecallum
i dont understand your obsession with air as thrust? it makes no sense.

you bun fuel with air/oxygen and the thats is your thrust.end of story.

His obsession with air as thrust is because that's how a jet engine works. As has already been stated here (but you still seem to ignore) is that jets are not like rockets. They don't use air (oxygen) simply to help fuel burn like a rocket, instead large amounts of air is compressed with the fuel and this mixture is burned. The burning fuel mixed with large amouts of compressed air together create thrust. That's LARGE AMOUNTS OF AIR. This why jets have such large air intakes that suck in plenty of air. The oxygen isn't just used for oxidation (burning). The amounts of air required for this purpose could not be carried by the vehicle.

re-entry is the opposite....

you slow down using engine power to normal aircraft speeds before coming back into the main atmosphere..no need for shielding ...high g forces or any unusual stresses....

Many of you cannot grasp the simple fact the present space shuttle and rockets burn/ use at least 95% of their fuel within the 10 mintues of takeoff and then are basically flying bricks/darts without any thrust.

that is why they need shielding and fancy materiels...

the 747 concept is the exact opposite.

To stay in orbit (in the equilibrium between gravity and centrical force that you described) you need to be moving at about 17,000 mph. If you move faster, your orbit starts to get wildly erratic (a large ellipse). If you move any slower, you start falling towards earth. I suppose you could stay at orbital altitudes at slower velocities by using constant thrust, but that would require tremendous amounts of fuel.

FYI, The space shuttle heats up because of the friction it encounters when it hits the atmosphere going 16,000 to 17,000 mph (yes, there is friction at those speeds, even in a thin atmospere).

So your 747 is just going to use its engines (lets imagine that the engines work in space for a second - see above) to slow the vehicle down from 17,000 mph. Slow down to what speed and how quickly? As soon as you start slowing down, you start falling out of orbit, and you encounter the friction of the atmosphere at speeds slightly below 17,000 mph. You can't slow down fast enough (without killing the crew or breaking the vehicle into pieces) to say that the friction won't affect you. And decreasing your velocity at a slower rate will put you in the same boat as the shuttle...you will encounter the thin atmosphere at speeds that produce friction heat.

Edit to add:

Originally posted by esecallum
posted on 22-1-2007 at 08:41 AM (post id: 2894377)
you will reach 100 km or 70 miles in under 20 minutes

70 miles is still sub-orbital. As I stated above, constant thrust will be required to keep you at that altitude (fuel storage?)



[edit on 22-1-2007 by Soylent Green Is People]

Another point, in addition to the above which as also been mentioned before is that the turbofan engines of planes like the 747 only get a small portion of their thrust from the combustion process, something like 70-90%, depending on engine type is purely the large volume of air drawn through the front fan, this is why these engines are 'high bypass' engines, simply because most of the air bypasses the central core (just look at how the engines have a large cowl and then a much smaller cowl projecting from the rear). You are talking about replacing a hell of a lot of thrust with on board oxygen, far too much in fact.

I also think this is just a wind up, as I said earlier, but I admit I am enjoying it

Originally posted by Soylent Green Is People

Originally posted by esecallum
i dont understand your obsession with air as thrust? it makes no sense.

you bun fuel with air/oxygen and the thats is your thrust.end of story.

you are totally wrong...

air does not produce thrust.

kerosene burned with air or onboard oxygen produces thrust...

look it up...

and where does the energy to turn the turbofan blades and accelerate the air come from???

from a onboard 12 volt car battery?

see? i have you stumped

the engine issue is irralevant...

and also you people are so well brain washed you cant see your own nose because of your fat face...

this is not an insult...

but an observation....

you have been so throughly conditioned that you can only spout what you have been told to believe is possible..


none of you seem to understand the concept of SUSTAINED thrust from ground upto 24000 mile....

above 100 km no friction exists...any thrust will accelerate a vessal to a higher and higher speed as no drag exists..no energy lost...


have any of you heard of this equation...

v=at

Originally posted by gfad

Originally posted by esecallum

Esecallum, you still havn't answered my question above about how you are going to slow the 747 down from mach 3 or whatever before it reachs 400,000 feet.

Secondly how do you propose turning the plane 180 degrees? Thirdly I think you will find that an engine operating on a wing that is travelling at mach 5 in the opposite direction is going to provide just a bit of stress on the wing, otherwise how is it going to slow it down?! I know 747 wings are built to deal with these stresses.

MACH 5 DOES NOT EXIST IN SPACE..

no stress without air in space...

without air as a reference point.

you rotate the 747 by using thrust from ONE of the engines ONLY...

THE ENGINE NEAR THE END OF THE WING..this will cause the 747 to start rotating...once u have turned you fire engine no4 to stop the spin...

its all so simple...

it called thrust vectoring in a horizontal plane....

i have an answer to every question....

[edit on 23-1-2007 by esecallum]

[edit on 23-1-2007 by esecallum]

Originally posted by esecallum
you are totally wrong...

air does not produce thrust.

Air does produced thrust - accelerate the air and you get an equal and opposite reaction


Equation for thrust for a turbojet engine:


T = Ma(V1-Va) + Mf(Va)

Where:

T = Thrust
Ma = Air mass flow rate through engine
V1 = Engine nozzle exit velocity
Va = Aircraft velocity (or ambient velocity)
Mf = Fuel mass flow rate into combustion chamber

For a turbofan there is an additional component Ma(BPR)(V2-Va)

giving

T = Ma(V1-Va) + Ma(BPR)(V2-Va) + Mf(Va)

where:

T = Thrust
Ma = Air mass flow rate through engine core
V1 = Core nozzle exit velocity
Va = Aircraft velocity (or ambient velocity)
Mf = Fuel mass flow rate into combustion chamber
BPR = Bypass ratio
V2 = Bypass nozzle exit velocity


So you see, for a turbojet engine, you need the air mass flow through the engine to generate thrust.




What you are proposing is a liquid fuelled rocket engine, both the fuel (here it would be kerosene) and oxygen are carried on the vehicle itself.

RICHARD CLAIMS

"4 million kg for fuel alone on an airframe designed with a maximum takeoff weight of 440,000kg on the newest, largest model the 747-8 (which has the same fuel capacity of the -400).

Yup, theres flaws in your arguement all right. "


Richard your calculations are totally wrong and flawed....AND APPLY TO THE SHUTTLE ONLY.!!!!

the 747 as it exists carries enough fuel in its wings to last for at least 10 hours...
modified versions can last for 20 hours....

look it up...

upto 50000 feet going upwards at a speed of 500 mph takes how long does it take richard??

work it out

from above 50000 feet to 400000 feet using onboard oxidizer how long does it take travelling at 500 mph..?

work it out


then from 400000 ft to 23000 MILES how lon does it take a 747 ACCELERATING IN FREE SPACe WITHOUT ANY DRAG ON SUSTAINED THRUST?

if you work it out the flight duration is about 2 hours and yet a 747 can sustain thrust for 10 hours minimum......

do you see now?

your calcultions about 8 million litres are connected to that space shuttle...this not the same...
its a winged vehicle based on continous efficient sustained thrust....








[edit on 23-1-2007 by esecallum]

[edit on 23-1-2007 by esecallum]

[edit on 23-1-2007 by esecallum]

[edit on 23-1-2007 by esecallum]

Originally posted by kilcoo316

Originally posted by esecallum
you are totally wrong...

air does not produce thrust.

AND YOU HAVE REFUSED TO EXPLAIN WHERE THE ENERGY TO MOVETHI AIR VERY FAST COMES FROM.



"What you are proposing is a liquid fuelled rocket engine, both the fuel (here it would be kerosene) and oxygen are carried on the vehicle itself."

YES AND NO


all along i have been saying use a jet engine below 50000 feet then onboard oxidser above..

Originally posted by esecallum

all along i have been saying use a jet engine below 50000 feet then onboard oxidser above..

Onboard oxygen in the same engine?


Because the design point of a turbofan engine and the design point of a liquid fuelled rocket are poles apart. You'd need seperate propulsion units.

Originally posted by esecallum
MACH 5 DOES NOT EXIST IN SPACE..
no stress without air in space...
without air as a reference point.

You are wrong. Again. As usual. As you have been when answering every question.

Of course stress can exist without air. You have a massive object with very high velocity travelling in one direction, it therefore has a large momentum, and then you apply a large force in the opposite direction on the wings of the craft.

Those wings would be under enormous and would therefore probably break off. The stress I'm talking about isnt air resistance, its trying to push something in a direction it doesnt want to go in.

Imagine a bowling ball with a beam coming out of each side, this models the plane. Now accelerate the bowling ball to a velocity. By applying a force to the ends of the two beams you are creating a rotational moment in two opposing directions and the beams are under extreme stress. This is independant of whether the system being modelled is in air or a vacuum.

The 747 wings are not built for these stresses.

PS. your writing style is very difficult to understand. Try to write in paragraphs like the big boys and without having to caps lock every other line.

Originally posted by esecallum
YES AND NO

all along i have been saying use a jet engine below 50000 feet then onboard oxidser above..

Kilcoo316 is right...what you seem to be proposing is a vehicle with two different types of engines to be used at different altitudes.

So you say above 50,000 ft you'll use the onboard oxidizer. And as we have discussed, you can't carry enough oxydizer to operate a jet engine, so as kilcoo316 pointed out, your vehicle must have both jet engines (for below 50,000 ft) and rocket engines (for above 50,0000). You do realize that jet engines and rocket engines work by totally different concepts. The onboard oxidizer mixing with the kerosene that you talk about describes a rocket engine, not a jet engine. As discussed, a jet engine requires the compression of large volumes of air.

So what you are proposing is to have rocket motors take over at 50,000 ft. Here are some questions I have regarding this second propulsion system on your vehicle:

• What is the thrust of these rocket motors?
  
• Is it enough to keep this 747 from falling?
  
• What is the fuel consumption of these rockets?
  
• Maybe a 747 can carry enough fuel in its wings to operate it's jet engines for 10 hours, but is there enough fuel to also operate rocket engines?

BTW, jet engines are very fuel efficient, rocket engines are not.

And you are still ignoring the problem of slowing down gracefully (from the 17,000 mph required to reach orbit) without burning up in the atmosphere, since your vehicle is minus a heat shield.

edit:spelling counts!

[edit on 23-1-2007 by Soylent Green Is People]