Project G42-200 StarLiner

[theflyingfish]

Wow, Moach, two posts in just over four hours! That's the quickest I've ever seen anyone ever create something in a developement thread!

Anyway, I have a few questions...

1. Is this vessel using the same Turbine/Rocket-RAMJET/SCRAMJET configuration of the first G42-100?

2. I read that you are using the droop-nose, Concorde-like cockpit, but your above "visor" drawing looks unlike a Concorde at all.

3. Is an Active VC planned? I saw the illustration, but I want to make sure.

4. Will UMMU and UCGO be supported?

I'm sure some of these are really stupid questions, so feel free to shoot me down!

 

[Moach]

1. Is this vessel using the same Turbine/Rocket-RAMJET/SCRAMJET configuration of the first G42-100?

roger that! - same engine setup, it feels realistic (possible, at least) and i have already coded it :thumbup:

2. I read that you are using the droop-nose, Concorde-like cockpit, but your above "visor" drawing looks unlike a Concorde at all.

it's a visor, but not a droop-nose... the idea is to simply shield the cockpit againt the murderous mach 20+ airflow... dropping the nose is not a necessity, since ours isn't too pointy and can deal well with high AoA

3. Is an Active VC planned? I saw the illustration, but I want to make sure.

you bet! - i'm a VC-junkie myself, and have really hard time enjoying craft without those...
i'm skipping the 2d panel, tho... why bother, i figured

so yep - will have VC, as shown in the illustration

4. Will UMMU and UCGO be supported?

i see no reason why not
the G42-100 already had URMS adapted as well, so you can count that in too:thumbup:


those are not stupid questions :tiphat: - thanks for asking!

 

[Hlynkacg]

approaching mach 1 with the visor down should result in most certain and very embarassing disaster :thumbup: - be sure to have it extended shortly after wheels-up

Perhapse it's operation should be tied to wing configuration. Wings out, Visor open. Shifting to Super-cruise or Re-Entry mode? Wings go up/down and visor closes.

Seems to me that it would save on the amount of animation code and button-pushing.

 

[HarvesteR]

Maybe, but then again, visor-up time might not be exactly at wings-down time... so that may be a compromising er... uhm... compromise.

and also, more buttons equals more awesome!! I'm sure Moach agrees with me on this :thumbup:

Cheers

 

[Spacethingy]

Wow, Moach, this looks like a proper "Tuesday-release" job! Cool work...

 

[Moach]

buttons = awesome! :thumbup: sure thing!

and yes, the wings should only come down at the start of RAMCASTER operations, which is around mach 2~2.5

at that point, with the visor down, the front windshields could very well have been spontaneously repositioned somewhere in the aft of the cargo bay... which should be now located anywhere within a 20nm radius from the cabin section :hmm:

so, independent switch it is :rofl:

i guess i'll write a full set of checklists, just as well to guide me on developing the many many simulated systems i envision this thing should have....


another not-shown feature, the G422 has canard fins around the cabin section - the reason they are not shown is because they are retractable (think Tu144, but less weird)
the purpose of those is to add pitch stability and maneuverability at subsonic speed...

otherwise, i highly doubt that the trailing edge elevons would have enough leverage to bring the nose up with the tanks full and all...

having the canards deployed should lower VR to a decent value, not at more white-knucle moments than desirable apart of V1...

the canards should be able to stick up to mach 2, then it's back in with them, lest they get blown off


let me draw 'em up... hang on..

---------- Post added at 10:41 AM ---------- Previous post was at 09:46 AM ----------

ok, this is what i have in mind...

the canards are mounted between the upper and lower cabin decks (which are connected through the non-blocked part between the compartments

in red, are shown the canard-box doors, which shield the inside things during the aerodynamically-unsound parts of the flight - those are closed at all times at which the canards are not in transit... and they slide themselves open under the outer fairing, to avoid exposing their railing grooves into, you know... mayhem :lol:

at the root of the canards, there's the actuator that pivots them up and down, as to control pitch and bank attitude - these actuators are not powerful devices, but they don't have to be, since the canards are load-balanced simply by the positioning of the pivot axis

 

[Grover]

this looks incredible, have you got any models done yet or is it only schematics and plans so far?

god luck with this!

 

[Moach]

alright - here's the real deal...

if you ever wondered if i was mad enough to actually devise how or earth the RAMCASTER engine really works....

you wondered right :thumbup:

let me brask it down for ya, shall we?


turbine mode - the airflow (expected at some AoA) is directed straight up to the turbine diffuser... this is a small turbine, by most standards, but it packs one big afterburner, hence the name "turbo-rocket"

of course, we can't really expect this to work above mach 2.5... the engine would suffer from all assorments of evil and eventually, blow up taking the ship, the crew and our self-respect with it :hmm:

so onto stage 2 - RAMCASTER (LOW)

what you're looking at in the second illustration, is a ram-jet, this is a device that provides thrust by igniting air that's compressed by the very airspeed of the craft, removing the spinning turbo-compressor...

while the airflow compresses, it slows down to subsonic, and heats up quite...

while this is good for us between mach 2~5, the heat at higher speed eventually will have the engine blow up taking the ship, the crew and our self-respect with it :facepalm:

so we now engage RAMCASTER-HIGH

the ram-gates are closed, then the diffuser advances towards the front of the chamber... this allows the airflow to reach the burner at supersonic speed :blink:

igniting the supersonic air, our now scram-jet blasts off into the limits of reasonable flying, propelling the G42 into out of this world... almost...

the scramjet also has it's limitations, and pushing further it would cause it to blow up taking the ship, the crew and our self-respect with it :uhh:

otherwise, upon reaching the top of the atmosphere, there's not much more air left to burn our fuel.... we should probably consider doing something about that... right?


then on comes the rocket! - now, without the turbo-compressor, the turborocket can still set itself up to function as a pure rocket, breathing the internal oxidizer supply we've been hauling all along...

and that - is how we get to orbit! :thumbup:

of course, once we get up there, all the fuel tanks will be pretty much dry...
this is e3xpected, once in orbit, the G42 uses an OMS pack, which is fueled by RCS monopropellant... that gets you around when you're up there....


back to work now :tiphat:

 

[Hlynkacg]

more buttons equals more awesome!! I'm sure Moach agrees with me on this :thumbup:

Ahhh, it's going to be one of those addons is it? :lol:

Actually I am inclined to agree, but it still seems like an awful lot of moving parts to me. I'm a firm believer in the "KIS" school of engineering.

Keep It Simple

Checklists will certainly be required.

 

[Grover]

thats some very technical stuff, i like it!

so it will reach orbit similarly to an XR, only it uses a turbofan for the taxi, initial ascent and then you hit the afterburner for mid-ascent to about 20k before RAM/SCRAM and rocket outta there

if i could suggest something though, make the afterburners only come on at throttle>80%, taxiing with twenty foot (flaming) exhaust jets isnt good for anybody

other than that, it looks AWESOME!

 

[HarvesteR]

neat!! I hope I can retain my self-respect long enough to get into orbit :shifty:

One thing though... is it sound to have the canard folding against the airflow?
In the event of mechanical failure, they would default to being extended... which, I imagine, mustn't be any good for one's self-respect...

In any case, losing the canards would be a bad thing... but, I think it's preferrable to have them fail undeployed than have them sticking out at a double-digit Mach numbers... I imagine one could still land without them, in an emergency...

Cheers

 

[Grover]

that is a good point, but in that event you could just perform aborted launch and go to the mechanic, youre still only at mach 2 (maybe 10KM alt?)

isnt this an active thread right now, its like a post every 30 seconds

 

[Moach]

that is a good point, but in that event you could just perform aborted launch and go to the mechanic, youre still only at mach 2 (maybe 10KM alt?)

yeah, a non-closing canard is a sure no-go that should pretty much ruin everyone's day... turn ship around, abort mission and land, no shame in that :hmm:

ripping out a canard... quite embarrasing :lol:

 

[HarvesteR]

What if the failure isn't detected until reentry time? Big oh noes!! :uhh:

Anyhow... minor detail really...

Moach, I suggest you start by texturing the VC (even not having one modelled )... So that gets done this time. hehe, Just messing with ya.

Cheers

 

[Grover]

you couldnt reach orbit if they were broken since they would have broken when you hit mach 3, on your way out of the atmosphere

besides, we dont know if failure simulations will even be put into this yet

 

[Moach]

What if the failure isn't detected until reentry time? Big oh noes!! :uhh: (...)

kinda hard to miss that... since the canards are clearly visible from the cabin windows

as for modelling, i have found that a certain times it is actually worth texturing first and modeling around that texture later.... it's easier to decide what goes where when you don't have a bunch of faces to map all at once :hmm:



edit::

@grover - i plan on simulating pretty much everything that could go wrong with this ship (that matters, of course... a ripped seat cushion is hardly an interesting failure).... but we shall see...

a also plan on realeasing WIP builds as i go along... helps keep the interest alive and then ppl get to play with whatever i have that far... i had been doing that already with the 100 model :thumbup:

 

[Grover]

ill happily beta test for you, and if you give me some specs, i might try to make a spaceport as well (built with a vessel like this in mind), though im struggling with a strange CTD on my own work at the moment, need to sort that out really (maybe using a single mesh for the hangars and apron was a bad idea after all...

 

[Schimz]

Nice looking. I love the engines.

She remind me the DGex mk2

 

[Grover]

wow that looks unstable, wing chord so far behind the vessel? must have some pretty heavy kit at the back to balance the whole thing out

 

[halcyon]

I tried your original G42 WIP, and I ran out of fuel before I was able to get to orbit.
Are you basing the orbital entry procedures of the G42-200 based on your old design? I ask because in your original G42, your instructions called for a hold at 20k to build up speed to Mach 7.5 before gaining more altitude.
This is incredibly fuel inefficient as 20k, or 65,616 ft still gives a lot of drag on an aircraft going that fast.
The XR2 by comparison uses 60k (196,850 ft) as it's altitude to get up to Mach 20. Not much drag up there.

Also, what's the max tonnage you're planning for a payload?