Kethane Pack 0.9.2 - New cinematic trailer! - 1.0 compatibility update

[Zephram Kerman]

...run out of KintakeAir... ...will not restart, even once back down at sea level.

So three questions:

1. Is this normal?

2. Is there any way to get more altitude out of the ZB turbine?

3. Has anyone used the ZBT on Eve, and if so how much altitude were you able to get out of it?

Thanks,

1) I think it's a bug with kethane. I see the same thing, and others have complained about it before. It might not be a bug, because the ZB uses a completely separate module than the regular jets for kintakeAir.

2) You could mess with the part.cfg to tweak the altitude profile.

3) I have not, but I expect it would do better there than on Kerbin or Duna.

With the way it works now, you might build your rescue plane to descend once and climb once. Glide to your target site, pick up your friends, start up the ZB and use it until flame-out.

[datdenkikniet]

oh, I'm going to use this so bad

[PUNiSH3R]

What I'm trying to do is build a Eve rescue spaceplane, using Kethane and the ZB turbine to get me through most of the atmo before switching to LFO engines.

I built a test craft and have been trying it out on Kerbin, and the problem I'm running into is that around 11-12km up I run out of KintakeAir. It seems to happen suddenly, one moment the resource bar is completely full, the next moment it's completely empty. This seems to happen regardless of speed, attitude, or throttle setting. Once the engines flame-out they will not restart, even once back down at sea level.

So three questions:

1. Is this normal?

Yes, the best way I can think of to describe it is as a compressor stall (the KE-J65 kIntakeAir model is BaseRate + (PowerRate * engine power) + (SpeedRate * air speed)). Essentially, the turbine is 'outrun' by the velocity of the airflow, the blades stall, aaaaaaand flameout... Hope you've got a good glide ratio until you can windmill that baby back up to operating speed. (AKA: it's not a bug, it's a feature)

2. Is there any way to get more altitude out of the ZB turbine?

Lower your airspeed and increase your drag coefficient; the theoretical service ceiling would be dependent on your design (read: C_d), but keep in mind that Eve's atmosphere has a scale height of 7km, so flying at 12km on Kerbin is equivalent to flying 28km on Eve. I haven't tried Eve on KE-J65's, however I have on Duna, with a service ceiling of 10km, which would be just under 46km (45,900ish) on Eve. See the XR-19 "Albatross" album in my sig for the design.

As a side note, the Duna SSTO on KE-J65s was horribly inefficient; replacing the turbine mass with LF/O for the single aerospike more than doubled the ÃŽâ€v.

[Galane]

Compressor stall is when the compressor is spinning too fast, trying to ram more air through the combustion chamber and turbine than they can handle. The air "packs up" and momentarily acts almost like a solid. Air stops flowing through the engine and the compressor (and turbine attached to it via the drive shaft) can spin even faster. It works quite like placing a hand over the inlet of a hair dryer.

Since air has quit flowing through the engine, it "unpacks" and can flow freely again. Suddenly there's a heaping gob of air smacking into an over-revved compressor. That can slam it almost to a halt and in real jet engines can cause major damage.

Compressor stall was a problem in the early years of jet engines, especially with the centrifugal compressors. Engineers had to learn how to balance the airflow so the compressor could not push too much air through. RPM never exceed limits*, intake restrictions and shaping were among the fixes for engines that had compressor stall problems.

*In other words, running the engine faster doesn't make the plane go faster, it makes the plane fall out of the sky with the engine spewing pieces out the tailpipe.

[PUNiSH3R]

Compressor stall is when the compressor is spinning too fast, trying to ram more air through the combustion chamber and turbine than they can handle. The air "packs up" and momentarily acts almost like a solid. Air stops flowing through the engine and the compressor (and turbine attached to it via the drive shaft) can spin even faster. It works quite like placing a hand over the inlet of a hair dryer.

Since air has quit flowing through the engine, it "unpacks" and can flow freely again. Suddenly there's a heaping gob of air smacking into an over-revved compressor. That can slam it almost to a halt and in real jet engines can cause major damage.

Compressor stall was a problem in the early years of jet engines, especially with the centrifugal compressors.

That's an excellent description of an axial-symmetric stall (aka, compressor surge), but the finicky KE-J65 makes me envision a rotational stall where a given blade row is at critical load, the airfoils generate a low pressure cell aft of the row and the pressure drop propagates, causing a flameout.

I think the intent was to replicate the issues inherent in early, zero-bypass designs that were prone to rotational stalls and keep us from enjoying too much benefit from burning straight Kethane...

[Majiir]

...and keep us from enjoying too much benefit from burning straight Kethane...

This is mainly it. It's a jet engine that can run without oxidizer, so there's some additional piloting challenge to keep it from being too overpowered. Tying intake performance to engine power was the easiest way I could think to do that. I'm open to suggestions on how to make it seem more realistic.

[PUNiSH3R]

I'm open to suggestions on how to make it seem more realistic.

I personally like it the way it is, it presents a unique challenge (I spent a good ten hours in-game designing the bird I referenced above (the XR-19 Albatross) to run well on Kethane, on Duna) but I understand how it could be frustrating. I think the biggest complaint comes from the inability to perform an in-flight restart after a flameout. You can technically 'windmill' the KE-J65 to an in-flight restart under its current design, but I've only managed it twice and both times had the yoke to the floor at <50m altitude and required a fresh pair of MAGs for Bill...

Perhaps a forgiving Kethane microturbine? With miniscule thrust and horrible fuel efficiency? I retract this suggestion, Majiir has an excellent point: "I'd rather not introduce new parts, since Kethane is fundamentally a resources mod, not an engines mod."

Edited March 20, 2014 by PUNiSH3R
New Info

[SSSPutnik]

Quick question, do I need a Kethane storage tank in order to mine and convert to fuel?

Ie can I get away with just a drill, converter and empty fuel tank?

[Superfluous J]

Quick question, do I need a Kethane storage tank in order to mine and convert to fuel?

Ie can I get away with just a drill, converter and empty fuel tank?

You need a Kethane tank. The Kethane must exist within your structure to be converted. If you're planning on converting it all instantly you don't need a big tank, just use the smallest one available.

[VaporTrail]

Am I right in assuming the Kethane tank size you need is capacity of your converter per unit time?

Basically if your converter converts one unit of Kethane per tick, and you can supply the tank with one unit per tick, the largest size Kethane tank you need is exactly one unit?

[psyper]

Quick question, do I need a Kethane storage tank in order to mine and convert to fuel?

Ie can I get away with just a drill, converter and empty fuel tank?

shameless plug:

You do need tanks - either that or you can use my add-on which add a small kethane tank inside the converters:

http://forum.kerbalspaceprogram.com/threads/71140-WIP-KSP-0-23-Kethane-Plus-v0-2

Its the Europa Edition that you need to download - and you'll need modulemanager if you haven't already got it.

[Zephram Kerman]

This is mainly it. It's a jet engine that can run without oxidizer, so there's some additional piloting challenge to keep it from being too overpowered. Tying intake performance to engine power was the easiest way I could think to do that. I'm open to suggestions on how to make it seem more realistic.

IMO, it's well balanced and not under|over powered. The only change I would suggest is to give some warning of impending flame-out. The way it is right now looks like a bug, because kIntakeAir suddenly drops to zero and basically does not reappear. If we could see the kIntakeAir meter do something meaningful, it would reassure folks that the mod is working as designed.

I definitely appreciate the intake being integral to the engine; the stock ones should work like this.

@P0wN1SH0R, your XR-19 Albatross will help me plan my own Duna plane. I'm hoping to make a self-refueling scout that hops between kethane patches. I've pulled it off on Kerbin and Laythe with air-breathing jets. Now it's just a matter of adapting those ideas for the ZB turbine and the conditions on Duna.

Edited March 20, 2014 by Zephram Kerman

[million_lights]

I searched the thread but this Issue wasn't discovered before so here we go.

I´m using Kethane 0.8.4 along with planet factory and the Sido Urania Planet Pack_v06.

The problem is that the Kethane-Grid-overlay in map mode is too small for the planet Eos (moon of Hermes).

If you move the camera inside the planet you can see the grid from the inside but the grid isn't visible from the outside of the planet.

Is there a specific value in a config file to adjust the size of the grid?

I hope I don't have to wait for a new Kethane update to fix this issue.

Love your mod and keep up the good work

[PUNiSH3R]

@P0wN1SH0R, your XR-19 Albatross will help me plan my own Duna plane. I'm hoping to make a self-refueling scout that hops between kethane patches. I've pulled it off on Kerbin and Laythe with air-breathing jets. Now it's just a matter of adapting those ideas for the ZB turbine and the conditions on Duna.

The critical design feature for Kethane turbine use on Duna is the multiple air brakes. You have to keep them deployed at all times except for takeoffs and landing. Otherwise the KE-J65 will provide too much thrust even at low throttle and high trim settings. V₂ is around 50 m/s. Control airspeed with your trim and altitude with your throttle. From my previous post, service ceiling is 10km and V_NE is 310 m/s (feels slow until you remind yourself: that's about 700 MPH). Range on 3000 units of Kethane is 900 km with a 10% reserve. Good luck, it's a great feeling when you get the right combo up in the air.

[SSSPutnik]

Thanks for the answers, was hoping to avoid needing a kethane tank.

A tiny radial mounted tank would be awesome.,

@psyper - maybe.. Be a bit cheat for challenge I'm on.

Edited March 22, 2014 by SSSPutnik

[corumanime]

I searched the thread but this Issue wasn't discovered before so here we go.

I´m using Kethane 0.8.4 along with planet factory and the Sido Urania Planet Pack_v06.

The problem is that the Kethane-Grid-overlay in map mode is too small for the planet Eos (moon of Hermes).

If you move the camera inside the planet you can see the grid from the inside but the grid isn't visible from the outside of the planet.

Is there a specific value in a config file to adjust the size of the grid?

I hope I don't have to wait for a new Kethane update to fix this issue.

Love your mod and keep up the good work

Hey, theres a file in the kethane folder called grid.cfg Look at the lines already in it, its to override scaling of the grid which is just what you want.

Add a line for Eos and maybe copy a value from a similar sized planet first, and then I guess its trial-and-error till you get it right.

Good luck!

[corumanime]

I have a problem, and the only hint was that a "rendering conflict with city lights was fixed in 8.3" but I'm using 8.4 (and yes, city lights mod) and both Kethane Drills are HUGE in the VAB, like 100 feet tall.

I've used Kethane for ages, this never happened before. Help?

[million_lights]

Hey, theres a file in the kethane folder called grid.cfg Look at the lines already in it, its to override scaling of the grid which is just what you want.

Add a line for Eos and maybe copy a value from a similar sized planet first, and then I guess its trial-and-error till you get it right.

Good luck!

Thank you so much corumanime!

Worked perfectly fine

[Iasus]

Is it possible to update to the latest version of the pack without overwriting the current kethane distribution map for my game? I am having the OCD-like craving to update but I am mid way though a Duna base mission and don't want the kethane under it to suddenly not be there any more!

Ias

[corumanime]

Thank you so much corumanime!

Worked perfectly fine

Millionlights I'm really happy it solved your problem! yay! I'm working my way through the planet packs so it will be a while before I get to see the Urania pack (too much RAM for them all) - is it fun to play?

I'm glad you're using Kethane successfully with it. I added CityLights/VisualImprovements and it makes the planets look AMAZING but it might have broken my kethane parts. Maybe I'll remove it and see.

add me on Skype - corum.anime - if you wanna chat or see what I mean by amazing looking or help me work out why my kethane drills got supersized.

Take Care,

Corum.

[Zephram Kerman]

Is it possible to update to the latest version of the pack without overwriting the current kethane distribution map for my game? I am having the OCD-like craving to update but I am mid way though a Duna base mission and don't want the kethane under it to suddenly not be there any more!

Ias

Yes, you can safely update without messing with the kethane distribution. The patch locations and quantities are stored in your persistent.sfs file.

[Buckshoot]

Can we transfer the kethane maps from one save game to another? I cant even finde the map files.

Can someone help me? I just don't want to do the scans again.

[Superfluous J]

Can we transfer the kethane maps from one save game to another? I cant even finde the map files.

Can someone help me? I just don't want to do the scans again.

I've never copied the data, but just search your persistence file for "Kethane" and it should be pretty obvious. It was for me when I erased all the data to start over in a save.

[Climberfx]

The showinmenu = false, could be in the original install, because is annoying when it appears on the start menu game.

And i always need to search this almost 100 pages thread for the codes again. Lucky me i have the old install to check on.

[psyper]

Can we transfer the kethane maps from one save game to another? I cant even finde the map files.

Can someone help me? I just don't want to do the scans again.

Like 5thhorseman said but you'll get the same resource fields as the old save with the same amounts of kethane - these are created randomly so if you did scan in your new save you'll get different locations for kethane. If you mine any resources these will not be in the new save either.