Spaceship design, for fun.

[ortemus74]

When I first designed the 747 spaceplane I didn't hear anything positive about the scramjet research... Then last year around March I heard mach 7 was acheived...<br />Then November I heard mach 10 was acheived... <br /><br />In reflection to the promising results of the 'new' scramjet technology I began to rethink the 747 & 717(or DC-9) spaceplane concepts...<br /><br />If I were to improve my idea from scratch I would streamline the wings and add a scramjet. Of coarse keeping the size the same it still would be a different spaceplane.<br /><br />I used the 747 because there were alot of facts about it. It made constructing a spaceplane easier.

 

[grooble]

Is it technologically possible to build a spacecraft that takes off from a runway, goes to high altitude, and then starts a scramjet, gets to several thousand mph, and then use some other engine to get to orbit, and then user a solar sail / ion engine to get the moon?<br /><br />

 

[le3119]

Is this actually space-worthy? Can we fly a commercial jet into space? One observation: I don't think that airframe can attain hypersonic velocities needed to make orbit. Doesn't such a spaceplane need a more aerodynamic airframe (such as a supersonic transport like the Concorde)?<br /><br />Note: The Shuttle does not need such an airframe, because it launches vertically, and enters orbit as a rocket (like Gemini, Saturn, etc).<br /><br />

 

[ortemus74]

It shouldn't matter as the atmosphere starts THINNING the drag on the 747 spaceplane will diminish. Also, the 747 spaceplane is fitted with steel girders and a reinforced hull making the wings and rear 'a hell of alot' stronger.<br /><br />Matt T.

 

[grooble]

I wonder what the son of concorde jet will be capable of?

 

[tap_sa]

Even if all the LOX/LH2 in those planes would be burned in as efficient rocket engine as SSME (Isp of 453sec), they would reach only about 3.9km/s speed. Not enough to make orbit, barely half.<br /><br />Why are you planning to use fuelcells to drive resistojets, instead of burning the propellants in conventional rocket engine?

 

[ortemus74]

I'm not burning the fuel... I'm using the capacitence of running the hydrogen fuel cells in parallel to charge the capacitor and then obtaining cell waste (water) to turn to STEAM. STEAM which increases standard rocket engines from 400lbs. of thrust per pound to 2000lbs. of thrust per pound.<br /><br />The reason why I'm using what I am using is because STEAM is more powerful than conventional rockets and it has been in use alot longer than rockets.

 

[tap_sa]

M'kay. Are you expecting to create hotter steam using this fuelcell approach than by burning the propellants in conventional rocket engine?

 

[ortemus74]

electrically, yes! <br /><br />Note: Charging the capacitor in parallel then using the waste as thrust!

 

[tap_sa]

What capacitor is being charged and why?

 

[ortemus74]

It's an almost instaneous process...<br />But to kept it hot a steel 'glow plug' (look at the 747&717 diagram) is used as a capacitor. It's hot to turn any left over 'cell waste into steam' to be used as thrust - if any water vapor were to touch the glow plug.

 

[tap_sa]

Let's see if I got it right now:<br /><br />1) fuel cells create water and electricity<br />2) fuel cell waste heat turns part of the water into steam<br />3) electricity is used to turn rest of the water into steam<br />4) steam pushes the plane<br /><br />Is that it?<br />

 

[le3119]

One other thing, the airframe of a 747 (or 717) is not designed for suborbital or orbital flight, otherwise the Shuttle would resemble a commercial jet. You don't have a lifting body that will survive reentry. There are heat and cold stresses in space that will strain the fuselage and probably break it apart. If that airframe where space-worthy, modified commercial jets would be the main choice for getting into orbit.

 

[ortemus74]

YES

 

[ortemus74]

Who are you to say that a 747 or 717 would have been the way to orbit when hydrogen fuel cells have only been around for a couple decades. Also, I invented this special method of using hydrogen fuel cells powered in 'PARALLEL' to be equivelent to a nuclear power source. When something is powered in parallel the voltages' are very very high.<br /><br />I'm not worried about space and re-entry breaking the spaceplane apart... I'm worried about the thrust from the steam doing alot more stress and strain to the fuselage. So, I added steel girders and reinforced hull to reinforce the wings and rear... The reinforced steel hull should take care of the stresses the fuselage will encounter.

 

[tap_sa]

Do you expect the fuel cell set-up extract more heat/energy from given amount of LOX/LH2 than just burning them would release?

 

[ortemus74]

YES - Steam generates more thrust than just burning LOX/LH2 together. Especially when steam is under PRESSURE. Putting the steam under pressure is what I plan on doing - with the electric hot wire mesh grid and steel glow plugs.

 

[tap_sa]

<font color="yellow">"Steam generates more thrust than just burning LOX/LH2 together. Especially when steam is under PRESSURE. "</font><br /><br />What do you think comes from rocket's nozzle that burns LOX/LH2 <img src="/images/icons/wink.gif" />

 

[ortemus74]

My thrust vectors' originated from microwave research. Basically nuke the water... Yes, the shuttle and other liquid launchers produce chemical reactions that make steam... Other solid rockets etc. make chemical reactions that produce thrust but not steam... None have topped 450lbs. thrust per 1lb. of fuel.

 

[tap_sa]

<font color="yellow">" None have topped 450lbs. thrust per 1lb. of fuel."</font><br /><br />The reason for this is that the energy to heat up the propellant comes from the propellant. <i>Just like in your system</i>. If you want to see higher specific impulses than what best existing LOX/LH2 rocket engines produce, you will need another/additional energy source. I don't see such in your spaceplane. <br /><br />edit: PS AFAIK RL-10B-2 has best Isp so far, 462 sec.

 

[grooble]

Can the heat on the aircraft from the high speeds be converted directly into energy?

 

[tap_sa]

Heat <i>is</i> energy but you probably mean could some of the heat (caused by airflow friction) be converted into additional thrust. Some, perhaps, but the additional plumbing mass required would probably negate the efficiency. In any case the 3.8km/s is absolute maximum attainable speed (in addition to the flight speed when steam engine is lit) , heat transfer plumbing in hull and wings could only help to reduce drag losses a little.