I made a ramjet!

[GoSlash27]

All,

I was thinking about the turbojet and how badly it imbalances the game, and it hit me: There really shouldn't be a turbojet engine.

IRL, nobody makes a turbojet capable of hypersonic speeds. Having one in the game seriously devalues the basic jet engine and the RAPIER.

That kind of performance is reserved for ramjets.

So then I thought "why not just convert the turbojet into a ramjet?" So I did.

This thing is pretty cool. It'll dump fuel below Mach 1, but won't ignite.

Once it lights off, it mimics the performance of the stock turbojet.

You can still use this part to make a hybrid SSTO, but now you'll need basic jets to get it supersonic.

I stripped out the alternator (no moving parts) and deleted the thrust vectoring.

I also got rid of the jet whine noise and sped up the throttle lag.

http://wikisend.com/download/908108/Ramjet.cfg

It goes in KSP/GameData/Squad/Parts/Engine/jetEngineTurbo.

It doesn't overwrite your stock config file, so you'll still have your turbojet if you want it.

Best,

-Slashy

[chengong]

I'm sorry but a quick notepad edit is not an add-on.

[Mecripp]

This won't work if your using VenStockRevamp and why didn't you just write like a MM patch ?

[GoSlash27]

I'm sorry but a quick notepad edit is not an add-on.

I agree, but where else would I put it?

[sal_vager]

Here's fine, nice work Slashy

[sidfu]

actualy its fine here in a way it is a addon. but its best to have more than 1 thing or make it a MM .cfg so changes are easly reversted by removingit

[NathanKell]

Here's fine, nice work Slashy

Seconded. Heck, until recently, Realism Overhaul itself was just Notepad++ edits. Lots of them, sure, but that's what MM patches are.

[GoSlash27]

All,

Thanks for the kudos, though as several folks have pointed out I haven't actually made anything new here.

I would've done this as an MM edit, except for a couple minor snags:

#1: I don't know how to do an MM edit

#2: I don't know what an MM edit is.

So there's that...

As it is, we're playing with this new toy over in the challenge section to see how much it has de-nerfed the turbojet WRT the other offerings.

Best,

-Slashy

[Captain Sierra]

All,

Thanks for the kudos, though as several folks have pointed out I haven't actually made anything new here.

I would've done this as an MM edit, except for a couple minor snags:

#1: I don't know how to do an MM edit

#2: I don't know what an MM edit is.

So there's that...

As it is, we're playing with this new toy over in the challenge section to see how much it has de-nerfed the turbojet WRT the other offerings.

Best,

-Slashy

Don't feel bad, not even I can competently write MM patches.

An MM edit is a .cfg file written for the Modulemanager plugin which allows you to change values in existing .cfg files without actually editing them. I believe you can also have it load the edited .cfg as a copy instead of a replacement (since you're not overwriting the stock turbojet) but that capability is beyond me.

[Mecripp]

Best, I can tell got it to work with VenStockRevamp mod here if you want hope, I got it all right.

+PART[turboFanEngine]
{
    @name = RamJetEngine
    @author = Slashy
    @title = RamJet Engine
    @description = An experimental jet engine with no moving parts. It uses supersonic shock waves to compress incoming air, and doesn't work below 300 m/sec.

    @MODULE[ModuleEngines]
     {
      @engineAccelerationSpeed = 0.4
      @engineDecelerationSpeed = 0.7
     }
     @velocityCurve
      {
        %key,0 = 0 0 0 0
        %key,1 = 300 0 0 0
	%key,2 = 350 .7 0 0
        %key,3 = 1000 1 0 0
	%key,4 = 2000 0.5 0 0
	%key,5 = 2400 0 0 0
	}
}

https://dl.dropboxusercontent.com/u/72893034/Ramjet.cfg.zip

Edited January 5, 2015 by Mecripp2

[kyklop]

For some my SCRAMJet engine I use this formula:

atmosphereCurve
 	{
	// key = Pk  Isp;  Isp_sl=600, Isp_air_max=2350, Isp_vac=320
	// 	Pk (atm)		Isp		// Kerbin - Earth
		key = 1			600		// sea level
		key = 0.15		2000		//10000 - 13280
		key = 0.05		2350		//15000	- 21000
		key = 0.02		2350		//20000	- 27400
		key = 0.004		2000		//27500	- 38650
		key = 0.0003		600		//40000	- 56780
		key = 0			320		// vac	
 	}

velocityCurve
	{
	//	speed m/s	%Thrust; 	speed Mach
		key = 0		0.5		// 0
		key = 333	0.75		// 1
		key = 1000	1		// 3
		key = 1666	1		// 5	
		key = 2333	0.5		// 7	
		key = 3000	0.05		// 9
	}

Main problem in high-speed and high-altitude fly - intake air.

[Streetwind]

Interesting! I've recently been wondering if I should restat the atmospheric engines for my own save (especially since I have extra engines from mods like Karbonite that beg for a bit more differentiation). I'm going to try out the feel of your engine, if only to see how you approached the topic

There really shouldn't be a turbojet engine. (...) That kind of performance is reserved for ramjets.

Not necessarily... when I looked into the topic, I was genuinely surprised to discover just how many obscure variations of turbine-driven jet engines there are under the sun. One particular example would the the so-called "air-turboramjet". Sounds badass, doesn't it? It's what you get when you put a turbojet in between the air intake and the ram combustor. Instead of relying on the intake pressure to feed the engine, this type has a high-speed, full-bypass compressor fan that actively presses air into the ram combustor.

Compared to a regular ramjet's utter simplicity, it's a really complex engine, requiring up to three propellants: the turbine in a full-bypass configuration doesn't get any of the air its compressor sucks in and therefore requires for example a dedicated hydrogen/oxygen supply in addition to the ram combustor's own fuel. But it has interesting advantages. The first being that it can drive the ram combustor even at standstill, meaning the plane can take off unassisted. And yet, you can still fly hypersonic with it. Apart from the fuels issue, this is actually by far the closest real-life analogue of how the ingame "turbojet" performs - it's not a turbojet at all, it's an air-turboramjet in disguise!

This thing is pretty cool. It'll dump fuel below Mach 1, but won't ignite.

Huh. How did you pull that off? According to the velocity curve, it should have zero thrust below 300 m/s. And zero thrust means zero mass flow, so it shouldn't "dump fuel" at all - it should simply sit inert?

Main problem in high-speed and high-altitude fly - intake air.

You could try adjusting the ratio of intake air to fuel. The turbojet has it at something like 15:1. Try changing it to 12:1 and see how that works out? Technically should cause a significant difference in altitude before flameout...

[Amishacker]

There really shouldn't be a turbojet engine. (...) That kind of performance is reserved for ramjets.

It's not the turbojets, Kerbin physics is 'spooky'. All the engines are unrealistic because they are grounded in spooky; airbreathers extra-so

I've been playing with similar ideas (ramjets/scramjets/AAR), but I have now accepted the opposite goal to the OP:

Interesting spooky Kerbin-flavored ram-compression engines that have a niche

I tried realistic, but the universe spat them out. Now I try fun/interesting

This is the kind of contortion we should realistically be involved in with hypersonic turbojets:

Part of my initial goal was modeling the blackbird engines (ain't we all?), but I found that dropping in the right numbers made really weird things happen, so I had to Kerbal-ify it.

A placeholder ramjet based on data from ramstats - and a healthy dose of Kerbalization.

I enjoy this ramjet topic, and I want to collaborate before I release anything stupid, so please crit - just be aware my goal is 'interesting' not realistic.

The scramjet on the tail there was stupid-stupid-'interesting' (press Z to melt engine), so I'll keep that under wraps for now.

NB: If you want to play with intakes, try very high and very low mass intake parts.

Big mass parts (EG NASP style lifting body) with modest intakes act like drogue chutes, very light intakes (besides being cheaty airhog stuff) suck in lots of air without contributing much to drag.

*spooooky*

You could try adjusting the ratio of intake air to fuel. The turbojet has it at something like 15:1. Try changing it to 12:1 and see how that works out?

Yep, changing the air ratio and increasing ISP are the two ways to make an airbreather suck less air, and that's the more direct one. Great idea.

Kyklops: nice, thank you for sharing

PS: Bonus fun, how far can you skip off the atmosphere and into deep space with my ramjet?