IDEA/REQUEST: Diverting Jet Thrust

[Hammer Tech]

I have an idea for a mod, and since I have ZERO modelling/texturing/coding ability I figured I'd throw it out here to see if it might inspire someone more talented.

I build a lot of jets, and one thing I have noticed that is missing from the vanilla game and to my knowledge not mod-added either is the ability to divert thrust from engines.

Looking at real-world jets I have seen quite a few examples where the engine is enclosed in the body and the thrust is diverted out the back (one obvious example being the Harrier's four vectoring nozzles fed by a single engine).

A way this could be achieved could be to have something like a cargo bay, but without doors, into which the engine is placed, then attachment points on the outside to which to affix "pipes" or something like that, which can then be routed to nozzles which would output the thrust, divided equally among them. I have taken the liberty of doing a bit of a diagram (don't laugh) to illustrate the concept I have in mind.

The red arrows represent the thrust, the black arrows represent attachments. There would be a variety of straight and curved pipes, and maybe a long bay and a short one, to accommodate different engine sizes. In my mind the nozzles are flat and wide, but I guess there could be a few varieties too, to suit different aesthetics etc., or maybe the different types could even have varying performance aspects.

Well, that's my idea. If any of you super talented bunch are inspired by it and wish to take it up, good luck!

If not, I'll keep dreaming

Peace.

[Hammer Tech]

Actually, it occurs to me that instead of having modular pipe pieces, it might be easier/better to have radially attaching nozzles and connections similar to the stock fuel lines, but specific to a "thrust" resource that's determined by the engine contained in the bay.

[nli2work]

B9 has a compressed air resource that is similar to this; though not used as primary propulsion. with a few config tweaks you should be able change that. I like the idea of off-set exhaust nozzle, allows for a front and back stack node. Separating nozzle from engine is great idea too... actually excellent ideas all around!

Edited October 31, 2014 by nli2work

[Hammer Tech]

Thanks! I will have a fiddle around with a backed up B9 to see what I can see, but I doubt I'll make much progress

It was partly actually using your RF pack which gave me the idea; I'm trying to build a Focke-Wulf 1000x3, and the engines on that are enclosed in a flying wing design. Currently it really looks the part but has no engines, cause I can't get them to look right

[Kerba Fett]

I think there is a mod for a Pegasus jet engine like a harrier uses. I never bothered to try it since the spacing between the nozzles is fixed and if it's got the same spool up delay as a regular jet engine it would be hard to use as a VTOL.

I did play around with vectored thrust VTOL's quite a while ago. I used radial mounted engines from the Bobcat HOME pack mounted on Infernal Robotics rotatrons.

I learned that you want to have a lot of pitch torque available, but roll and yaw don't really matter much. You also want to make sure your COM doesn't change as you burn fuel.

I found that if you swivel all of your lift engines it's very unstable. I ended up using 4 fixed lift engines and 4 vectored engines. It made the transition from hover to forward flight much easier.

I'm on my iPad so I can't easily include a link, but if you want to check out my designs look in the Missiion Reports forum for a thread called "fun with VTOL's"

While I used rocket engines with the ISP adjusted, a better way to implement what you're looking for would be to have a compressor that consumes fuel and intake air and produces a new resource called pressure. You then have a set of engines that use pressure as their fuel. this should allow it to act as a jet engine without the throttle lag.

If you add too many engines and they're consuming pressure faster than the compressor produces it then you'd get engine failures.

It would work just like the relationship between solar panels and ion engines.

[nli2work]

a compressor that consumes fuel and intake air and produces a new resource called pressure. You then have a set of engines that use pressure as their fuel. this should allow it to act as a jet engine without the throttle lag.

If you add too many engines and they're consuming pressure faster than the compressor produces it then you'd get engine failures.

It would work just like the relationship between solar panels and ion engines.

That's exactly what B9 does with the CompressedAir RCS block. Just remember when using ModuleEngines you need at least one Propellant with mass.

[Hammer Tech]

Hmm. I'll see if I can figure a system out, modifying B9's bits and bobs. I literally have never done any part editing other than adjusting the amount of fuel in a tank, so I'm not hopeful XD

[Kerba Fett]

When I'm editing configs I usually try to find examples in other config files. For an example of a part that produces a resource look at the RTG config. For an example of a part that consumes the resource look at any probe core config.

Editing config files for something like this will take a bit of trial and error so a stripped down install of KSP will be a big help. Make a copy of your KSP directory and delete most of the parts except for the few you're working with. Your load times will be much faster.

You can also reload the part database without quitting the game by going to the debug menu (ALT f12 I think) and selecting reload all in the parts tab. This will apply any config changes to the parts in the game.

[nli2work]

B9 uses ResGen plugin as the converter module. converter takes ElectricCharge and IntakeAir as inputs; and outputs B9CompressedAir resource. I would start by copying the Air RCS block config and change the ResGen module's inputs to something like LiquidFuel and IntakeAir; leaving rest the same, and see if it behaves as expected. change one thing at a time and see what happens, whether's what you expect or not.

ALT-F11 brings up ModuleManager's database reloader, I recommend using this one.

ALT-F12 brings up Squad's database reloader;

[Hammer Tech]

Cheers guys; I really appreciate the help.

My laptop is messed up atm, but after I get it fixed I'm gonna start figuring stuff out. I have some pretty cool ideas for this once I figure it out