[1.0.5] Advanced Jet Engine v2.6.1 - Feb 1

[Camacha]

Ok...run this test for me then if you have doubts of AJE's fuel usage... Download RF, but don't install it yet.

Make a simple test plane...let's say a launch clap, a tank an intake and what ever engine you want.

I think the whole point of AJE is that stock engine behaviour and fuel consumption is ridiculous.

• 
  [*=left]My plane consumes fuel ridiculously fast. Fast yet realisticly rather than ridiculously. An F-16 that uses 1 x Pratt & Whitney F-100 has 3000 kg internal fuel, yet only lasts for minutes with full afterburner on. To see your airplane fly longer, either carry more fuel, restrain from using afterburner, or climb higher to save fuel.
  

[DivisionByZero]

So, I was messing around trying to understand the mod better. I gotta say, it's pretty nifty. I made a simple plane with the B9 Mk2 parts specifically to test the ramjet engines. I loaded up with kerosene and had 2 shock-cone intakes. The engine setup was one of the pratt-whitney engines that has pretty high thrust (150 I think?) for take-off and initial climb/accel and then 2 ramjets. I had that PW engine on full throttle most of the time (not sure if it is AB or not) and eventually was able to switch over to nothing but ramjets once the PW started hitting too-high a temperature. The plane was flying for about 30 minutes before I swung the stick a little too hard and it broke up at mach 4.2 at 20km up (thanks FAR!). Anyway, I was starting to run low on fuel by 30 minutes, but it seemed a decent flight-time to me. I also gotta say it was pretty fun trying to sort out how to trick the ramjets into working. Too bad they top out at M=4.4 (seems low).

[Renegrade]

By the way, I've noticed that the intake fuselage (T5, stock, same node as the radial intake) doesn't have an AJE inlet configuration.

I added the following to make it equivalent to a single radial intake:

@PART[MK1IntakeFuselage]:AFTER[AJE]
{
	@description=Pitot tube inlet, designed for subsonic flight

	MODULE
	{
		name=AJEInlet
		Area=0.2
		TPRCurve
		{
			key = 0.0	0.95	0	0
			key = 1.0	0.97	0	0
			key = 1.5	0.90	0	0
			key = 1.8	0.80	0	0
			key = 2.0	0.70	0	0
			key = 2.5	0.45	0	0
			key = 3.5	0.00	0	0
		}
	}
}

That seems to resolve the issue.

(Please feel free to use it if it's handy. It's just a copypaste anyways )

[camlost]

So, I was messing around trying to understand the mod better. I gotta say, it's pretty nifty. I made a simple plane with the B9 Mk2 parts specifically to test the ramjet engines. I loaded up with kerosene and had 2 shock-cone intakes. The engine setup was one of the pratt-whitney engines that has pretty high thrust (150 I think?) for take-off and initial climb/accel and then 2 ramjets. I had that PW engine on full throttle most of the time (not sure if it is AB or not) and eventually was able to switch over to nothing but ramjets once the PW started hitting too-high a temperature. The plane was flying for about 30 minutes before I swung the stick a little too hard and it broke up at mach 4.2 at 20km up (thanks FAR!). Anyway, I was starting to run low on fuel by 30 minutes, but it seemed a decent flight-time to me. I also gotta say it was pretty fun trying to sort out how to trick the ramjets into working. Too bad they top out at M=4.4 (seems low).

Good to know, I haven't play-tested the new ramjet since code rewrite

@Renegrade, better not do this before ferram4 figures out something more advanced. Currently, FAR would ignore drag of a part with inlet.

[blowfish]

@Renegrade, better not do this before ferram4 figures out something more advanced. Currently, FAR would ignore drag of a part with inlet.

Won't that happen regardless though? FAR determines if something is an intake based on whether it has ModuleResourceIntake, not AJEInlet, and it doesn't remove the ModuleResourceIntake from the stock part...

[camlost]

Won't that happen regardless though? FAR determines if something is an intake based on whether it has ModuleResourceIntake, not AJEInlet, and it doesn't remove the ModuleResourceIntake from the stock part...

Better inform ferram4 to change that then.

[Xenro66]

Oh crap, this might clash with Stock Revamp.... Can anyone confirm this please before I try it? I don't want to have to remove Stock Revamp to use this mod. I wan't an extra challenge when it comes to space planes, and this is it lol. The reason I don't want to remove Stock Revamp is because it looks so much better than stock, and most of my saves will break because they use parts exclusive to that mod. Also, one last thing... Does it change the values of B9 engines? If so, that's great.

I'm gonna download this for now, but I won't install it until I get an answer

[camlost]

Oh crap, this might clash with Stock Revamp....

No.

[Vegatoxi]

Finally fgure out how to keep my fuel, but have another issue now.

Cant get up more than 15-17km. Even with full afterburner.

Engines dont provide enough thrust, although without AJE i have stable flight up to 20-25 km on 2.5+ mach.

[blowfish]

Finally fgure out how to keep my fuel, but have another issue now.

Cant get up more than 15-17km. Even with full afterburner.

Engines dont provide enough thrust, although without AJE i have stable flight up to 20-25 km on 2.5+ mach.

In AJE (and real life) thrust drops off with atmospheric density, so it's unsurprising that you're hitting a flight ceiling. In stock thrust only drops off with speed, enabling you to fly much higher.

[Vegatoxi]

In AJE (and real life) thrust drops off with atmospheric density, so it's unsurprising that you're hitting a flight ceiling. In stock thrust only drops off with speed, enabling you to fly much higher.

I know that, but in career, visual survey contracts require a lot of survey above 18-19 km, with AJE it's impossible.

And rocket planes isn't good option when you need to fly-by 4 points on other side of Kerbin with 100-150 km between each other.

[camlost]

Kerbin's atmosphere is 0.7 times rescale of Earth. So the question is, in reality, what kind of airplane is able to fly at ~30km altitude. That is not a trivial task as what Squad fools you into believing. You'll need something like U-2, or SR-71, or X-15, to do it. Or proper use of ramjet as mentioned previously.

[Tidus Klein]

Hop it's what I do, fly as fast as you can at 16,000 or higher if you can, Mach 2 is a good speed, then jam the stick into your groin at full AB and hope you don't stall, (good craft design plays in there) you can normally hit 18,000 + like that. My highest hop was 22,000+ so I know it's doable

[DivisionByZero]

I'm playing a career game on 6.4x kerbin and barely have anything unlocked. In fact, I don't even have landing gear completed yet! I got a contract to test a couple of the first few engines available (P&W JT8Ds I believe) splashed down. Well, the things are big enough I figured I'd try to build a plane and get a visual survey contract out of it as well.

Take-off was tricky as I used some of the large sounding rockets to take off straight up and down, but it works.

Anyway, The plane is really just a Mk. 1 cockpit, 2 KW rocketry tanks filled with Kerosene, some straight wings, the two engines and some control surfaces. The massive amount of parachutes are since I have to splash it down, I need to be gentle. here's a pic:

I left FAR open so people could see some of the important parts:

estimated endurance: 3.3hr

estimated range: 3,000km

I was flying this at 18500m and could probably have gone a little higher with a bit more patience. The engines were only producing about 11kN of thrust each at this altitude, but I was holding it steady at M=0.9. (I should note that the 6.4x kerbin scales the atmosphere a bit relative to the base game, so I have a bit more air at 18.5km than stock Kerbin will).

An alternative to using the high-speed climb trick for high-altitude tests (a favorite of mine before I started using AJE), you might go for a high-lift, slow craft like I'm showing here. (part of me is wondering if I can throw more intakes on this to get a little more altitude...)

Anyway, I also gotta say that the widgets and new editor tools make building planes really nice now.

Edited January 5, 2015 by DivisionByZero

[Xenro66]

No.

It won't? Are you absolutely sure? I don't want to install it to find out that it messed up my gamedata folder, because I'd have to delete it and put all my mods back in which takes forever.

[Camacha]

It won't? Are you absolutely sure? I don't want to install it to find out that it messed up my gamedata folder, because I'd have to delete it and put all my mods back in which takes forever.

Making a backup will not hurt in any case.

[blowfish]

It won't? Are you absolutely sure? I don't want to install it to find out that it messed up my gamedata folder, because I'd have to delete it and put all my mods back in which takes forever.

How could it possibly clash with stock revamp? AJE uses MM configs to add its module to stock parts and Stock Revamp (now) uses MM configs to replace the models of stock parts. Neither overwrites anything that could be used by the other.

[NonWonderDog]

Ven's revamp does add an air intake to the Mk1 Cockpit, but that won't conflict as much as just not do anything.

You can always add this to make it work:

@PART[Mark1Cockpit]:NEEDS[AJE,VenStockRevamp] {
    MODULE {
        name=AJEInlet
        Area=0.2
        TPRCurve {
            key = 0.0   0.95    0   0
            key = 1.0   0.97    0   0
            key = 1.5   0.90    0   0
            key = 1.8   0.80    0   0
            key = 2.0   0.70    0   0
            key = 2.5   0.45    0   0
            key = 3.5   0.00    0   0
        }
    }
}

[blowfish]

AJETester seems to be giving me negative SFC in at least one situation: input parameters for B9 Sabre S, then bring speed all the way up, temperature down to 1-3 kPa, then bring throttle down below about half.

[camlost]

Ven's revamp does add an air intake to the Mk1 Cockpit, but that won't conflict as much as just not do anything.

You can always add this to make it work:

@PART[Mark1Cockpit]:NEEDS[AJE,VenStockRevamp] {
    MODULE {
        name=AJEInlet
        Area=0.2
        TPRCurve {
            key = 0.0   0.95    0   0
            key = 1.0   0.97    0   0
            key = 1.5   0.90    0   0
            key = 1.8   0.80    0   0
            key = 2.0   0.70    0   0
            key = 2.5   0.45    0   0
            key = 3.5   0.00    0   0
        }
    }
}

I advise against doing this, the way FAR treats inlet currently, you'll have a cockpit with no drag. You need a custom FARBasicDragModel as well.

AJETester seems to be giving me negative SFC in at least one situation: input parameters for B9 Sabre S, then bring speed all the way up, temperature down to 1-3 kPa, then bring throttle down below about half.

Then it's not supposed to work in that situation, your point being?

[blowfish]

Then it's not supposed to work in that situation, your point being?

It gives positive thrust. What's my indication that it isn't supposed to work? If it's a question of TPR is there a mach number readout somewhere on the interface?

[blowfish]

Possible bug report, may need to take more data to confirm: It appears that all hybrid engines (B9 Sabre, RAPIER, Mk4 Scimitar) are overheating incredibly quickly in closed cycle mode.

EDIT: Confirmed that AJE is causing the problem. Engines without the AJEModule do not overheat immediately in closed cycle mode.

EDIT2: I suspect this is because the part's max temperature is lowered to the value of TIT by AJE, but the closed cycle heat production remains the same. One possible solution is to lower the heat production in rocket mode via MM.

Edited January 7, 2015 by blowfish

[blowfish]

This cfg seems to fix the problem, though the factor 0.1 was chosen rather arbitrarily

@PART[*]:HAS[@MODULE[MultiModeEngine],@MODULE[AJEModule]]:AFTER[AJE]
{
	@MODULE[ModuleEngines*]:HAS[#engineID[ClosedCycle]]
	{
		@heatProduction *= 0.1
	}
}

[camlost]

That should not be part of this mod. What you reported should because of AJE setting max temp but not the heatproduction of the second engine module. I'll try fix this in dll

[Tellion]

Out of curiosity, what are the displayed Isp values for the B9 Sabres ASL for you? I was a little surprised about 20k today

Surely i have something installed incorrectly, but i would like to know for sure before i delve in the mysteries of my gamedata folder...