[1.10.x] Mark IV Spaceplane System (August 3)

[blowfish]

16 minutes ago, MinimalMinmus said:

" CKAN related question = no"...

This mod has been on CKAN for a while.  If you don't see it, it's because you're on KSP 1.2.2 and no version marked as compatible with KSP 1.2.2 has been released.  Nertea does not maintain the metadata but it will update automatically for the most part.

[MinimalMinmus]

5 hours ago, blowfish said:

This mod has been on CKAN for a while.  If you don't see it, it's because you're on KSP 1.2.2 and no version marked as compatible with KSP 1.2.2 has been released.  Nertea does not maintain the metadata but it will update automatically for the most part.

Is it? Oh, my bad then! Is there any way to install it via CKAN neverthenless?

[damerell]

1 hour ago, MinimalMinmus said:

Is it? Oh, my bad then! Is there any way to install it via CKAN neverthenless?

Check it works with a manual install, and submit a PR to CKAN to fix the metadata, or an issue to CKAN reporting that it works.

[JAFO]

9 hours ago, MinimalMinmus said:

Is it? Oh, my bad then! Is there any way to install it via CKAN neverthenless?

Yes.. Open CKAN, then click on the <Settings> menu, and you'll see a <Compatible KSP versions> entry. You can then set CKAN to allow mods for all 1.2 versions.

[Nertea]

On 1/23/2017 at 6:11 PM, Jarin said:

This should be pretty close. Though I think it'll happen to any Mk4 craft. If it doesn't, I'd love to see how to avoid it.

I think that I might have found the problem! I will be making a release today.... might have a fix for this. At least, the drag seemed to be similar to a fuselage piece.

[Nertea]

Mark IV Spaceplane 2.3.4

• Marked for KSP 1.2.2
• Updated CRP to 0.6.4
• Updated MM to 2.7.5
• Updated B9PartSwitch to 1.5.3
• Updated Firespitter to 7.5.1
• Updated DeployableEngines to 2.1.0
• Fixed node size issue in SCIMITAR cfg
• Some tweaks to Crew Cabin drag parameters
• Fixed a MM path throwing errors on startup

[Spin]

Thanks for the update of this great contribution.

[jmill050]

Thank you for keeping this up to date. This mod is basically my entire career endgame. Get far enough make amazing interplanetary SSTOs that can transport entire bases. Cheers

[Jarin]

Mk4 Testbed back out and flying. Still seeing 180+ kN drag on the cockpit at 3° pitch. Mach 0.98 at sea level. Less than 1 kN on the service bay, and 200kN on the medium fuselage. 

For troubleshooting purposes, I tweaked the wings to get the fuselage pitch as close to 0° as possible. At 0.1° pitch, things get interesting. The cockpit's drag is down to 67kN, and the fuselage is clear down to 30kN. Total craft drag was right at 1000kN on the original craft file I provided, vs 545kN with the wings inclined to pitch the fuselage almost level.

The Mk4 Shoulder Intake is still showing 5-6 times the drag of the stock shock cone, as well (8.8kn vs 1.5 tested side by side). 

Hope this is helpful. Please let me know if there's anything else I can do. 

Edited January 26, 2017 by Jarin

[gilflo]

Thank's for update, but it's still impossible to add  tank, cargo or whatever behind the vulture cockpit

[Temeter]

On 25.1.2017 at 7:34 PM, Nertea said:

Mark IV Spaceplane 2.3.4

• Marked for KSP 1.2.2
• Updated CRP to 0.6.4
• Updated MM to 2.7.5
• Updated B9PartSwitch to 1.5.3
• Updated Firespitter to 7.5.1
• Updated DeployableEngines to 2.1.0
• Fixed node size issue in SCIMITAR cfg
• Some tweaks to Crew Cabin drag parameters
• Fixed a MM path throwing errors on startup

Thanks for the update! I checked out the those lifting engines, having never used them, and they look like they are perfect for ships, since they can run of electricity from nuclear reactors.

They do seem like they got some smaller bugs, though?

On pad, the ultra heavy lift fan can run with 694kn of thrust, with a 0.04 LF consumption rate, which seems incredibly low. Compared, the big stock turbofan has 0.52 at 324kn of thrust.

It's a bit weird, since the u-heavy fan should be a tiny bit less efficient at LF consumption (having lift fan 12400 ISP vs turbofan 12600). Tried to take a look at the cfg's, might be because they use very different air/fuel ratios (air 25 to 227)?

 

Another smaller visual thing I've noticed, the fan animations are a bit weird in electrical mode. Sorry if this is hard to describe! LF mode is fine, however with electric, I'm only getting the slow standby animation when statically sitting on the launchpad, even when they produce ~630 kn's of thrust. Only under higher speeds, when the engines get faster as well, I'm getting the full power animation (with the near transparent blades). Also a somewhat jumpy transition. Not a big deal, just noteworthy because the LF animations look very good and smooth. Same with the medium sized lift fan, they go to 323 kn and dont spin at all (only spin after some time in the air). Small one seems to be fine on launchpad.

 

They do look awesome, tho.

Edited January 27, 2017 by Temeter

[Nertea]

On 1/26/2017 at 8:11 AM, gilflo said:

Thank's for update, but it's still impossible to add  tank, cargo or whatever behind the vulture cockpit

I think you are on your own here. Probably a mod or version conflict, neither me or anyone here seems to be able to reproduce this.

 

On 1/25/2017 at 7:30 PM, Jarin said:

Mk4 Testbed back out and flying. Still seeing 180+ kN drag on the cockpit at 3° pitch. Mach 0.98 at sea level. Less than 1 kN on the service bay, and 200kN on the medium fuselage. 

For troubleshooting purposes, I tweaked the wings to get the fuselage pitch as close to 0° as possible. At 0.1° pitch, things get interesting. The cockpit's drag is down to 67kN, and the fuselage is clear down to 30kN. Total craft drag was right at 1000kN on the original craft file I provided, vs 545kN with the wings inclined to pitch the fuselage almost level.

The Mk4 Shoulder Intake is still showing 5-6 times the drag of the stock shock cone, as well (8.8kn vs 1.5 tested side by side). 

Hope this is helpful. Please let me know if there's anything else I can do. 

So I stuck the Mk3 cockpit on the front of the test ship saw it generating ~70 kN of drag at around the same speeds. Considering that the Mk4 cockpit has about 2x the front cross-section area, 150 kN seems fine. So that's alright. 

The shoulder pieces are a bit different. Looks like the shock cone has a custom drag model that makes it very much less draggy than the shape should be. That I can probably adjust.

Would you say the crew cabin is resolved, at least?

 

59 minutes ago, Temeter said:

Thanks for the update! I checked out the those lifting engines, having never used them, and they look like they are perfect for ships, since they can run of electricity from nuclear reactors.

They do seem like they got some smaller bugs, though?

On pad, the ultra heavy lift fan can run with 694kn of thrust, with a 0.04 LF consumption rate, which seems incredibly low. Compared, the big stock turbofan has 0.52 at 324kn of thrust.

It's a bit weird, since the u-heavy fan should be a tiny bit less efficient at LF consumption (having lift fan 12400 ISP vs turbofan 12600). Tried to take a look at the cfg's, might be because they use very different air/fuel ratios (air 25 to 227)?

 

Another smaller visual thing I've noticed, the fan animations are a bit weird in electrical mode. Sorry if this is hard to describe! LF mode is fine, however with electric, I'm only getting the slow standby animation when statically sitting on the launchpad, even when they produce ~630 kn's of thrust. Only under higher speeds, when the engines get faster as well, I'm getting the full power animation (with the near transparent blades). Also a somewhat jumpy transition. Not a big deal, just noteworthy because the LF animations look very good and smooth. Same with the medium sized lift fan, they go to 323 kn and dont spin at all (only spin after some time in the air). Small one seems to be fine on launchpad.

I'll check this when I can. The problem is that firespitter doesn't like multimode engines much, I tried to hack it to do so without much success.

[Temeter]

12 minutes ago, Nertea said:

I'll check this when I can. The problem is that firespitter doesn't like multimode engines much, I tried to hack it to do so without much success.

I see. Functionally, most things work, though, and the animations aren't that much of a deal. Most notable is just the fuel consumption being borked.

[Jarin]

29 minutes ago, Nertea said:

So I stuck the Mk3 cockpit on the front of the test ship saw it generating ~70 kN of drag at around the same speeds.

Built a Mk3 craft with basically the same profile. At the same 3° pitch, I'm seeing a bit under 50kN to the Mk4's 180 on the cockpit. Still, it's fatter and less aerodynamic in general, so I suspect this is just an engineering challenge at this point, not a bug. Maybe that divot at the bottom/back of the cockpit is doing unfortunate things to the drag model? Don't actually know how it functions behind the scenes. Or not, since, I tossed on the Vulture cockpit for comparison and got 220kN drag; notably more drag where I would have expected less. I'm clueless at this point. I think the takeaway is just to build the wings to keep the fuselage as close to 0° pitch in the transonic zone as possible. Aero is weird.

[Jarin]

On 1/26/2017 at 8:11 AM, gilflo said:

Thank's for update, but it's still impossible to add  tank, cargo or whatever behind the vulture cockpit

Remember, there's a lot of mod folders with the Mk4 download. If you want to do a fully clean install, you need to delete all of "B9PartSwitch" "CommunityResourcePack" "DeployableEngines" "Firespitter" "MarkIVSystem" and "NearFutureProps" directories, then re-copy them to GameData from a fresh download of Mark_IV_Spaceplane_System-2.3.4.zip

[Nertea]

On 1/27/2017 at 1:36 PM, Jarin said:

Built a Mk3 craft with basically the same profile. At the same 3° pitch, I'm seeing a bit under 50kN to the Mk4's 180 on the cockpit. Still, it's fatter and less aerodynamic in general, so I suspect this is just an engineering challenge at this point, not a bug. Maybe that divot at the bottom/back of the cockpit is doing unfortunate things to the drag model? Don't actually know how it functions behind the scenes. Or not, since, I tossed on the Vulture cockpit for comparison and got 220kN drag; notably more drag where I would have expected less. I'm clueless at this point. I think the takeaway is just to build the wings to keep the fuselage as close to 0° pitch in the transonic zone as possible. Aero is weird.

So confused about this now heh. I think potentially the ModuleLiftingSurface contributes to the drag numbers, which would explain the huge deviation with AoA. 

[Jarin]

8 minutes ago, Nertea said:

So confused about this now heh. I think potentially the ModuleLiftingSurface contributes to the drag numbers, which would explain the huge deviation with AoA. 

Yeah, that's what I was thinking. Those fuselage parts have as much lift as most wings. I need to experiment with Mk4 in more lifting-body design and compare drag to traditional craft.

[Nertea]

13 minutes ago, Jarin said:

Yeah, that's what I was thinking. Those fuselage parts have as much lift as most wings. I need to experiment with Mk4 in more lifting-body design and compare drag to traditional craft.

I do also appreciate input on these numbers. I kinda just took the approximate XY size of a Mk4piece and gave it a lift rating equal to an equivalent area of wings. 

[sh1pman]

I have a VERY strange drag problem. I built two almost identical spaceplanes. The first one has two long cargo bays, while the second has four small bays. So you'd think that they fly similarly? Well, no. Not at all. The first one can easily get to LKO with 1000+ dv left, and the second one... can't even break the sound barrier.

Something creates a HUGE drag for the second plane. I don't know how to measure the exact numbers, so I took these screenshots with aerodynamic overlay enabled:

At transonic speeds this phantom drag becomes so ridiculous that even eight of those 2.5m rapier engines can't break the barrier.

I can provide the craft files if needed.

[Jarin]

2 hours ago, Nertea said:

I do also appreciate input on these numbers. I kinda just took the approximate XY size of a Mk4piece and gave it a lift rating equal to an equivalent area of wings. 

Looking at how actual lifting body craft are designed, it might be best to drop that wing area a bit. Despite KSP wings just being "drag + angle of incidence = lift", they're theoretically abstracting actual wings, and fuselage components aren't shaped that way. The Mk4 is really just a widebody cargo craft. It's the same problem the Mk2 stock pieces have, just writ large. Actual lifting body craft (as opposed to shuttle-type designs which are supposed to be draggy as hell) are supposed to get a higher lift-to-drag ratio than traditional wings. They also look closer to flying wings than widebody aircraft.

2 hours ago, sh1pman said:

I can provide the craft files if needed.

Please. I'd be happy to put them through the wringer and figure out what's breaking. (Also, is it all mk4, or are you getting engines and other parts from another mod?)

Edited January 31, 2017 by Jarin

[sh1pman]

1 hour ago, Jarin said:

Please. I'd be happy to put them through the wringer and figure out what's breaking. (Also, is it all mk4, or are you getting engines and other parts from another mod?)

Wings are from Procedural Parts, everything else is mark4. Wings barely produce any drag though.

[Jarin]

2 hours ago, sh1pman said:

Wings are from Procedural Parts, everything else is mark4. Wings barely produce any drag though.

Just wanting to know what I'll need to test them if you upload the .craft files

 

[sh1pman]

4 minutes ago, Jarin said:

Just wanting to know what I'll need to test them if you upload the .craft files

 

I'll upload them tomorrow, ok? It's just too late here already.

[Jarin]

15 minutes ago, sh1pman said:

I'll upload them tomorrow, ok? It's just too late here already.

No problem. I'll go figure out procedural wings in the meantime. Never used it before, myself.

[sh1pman]

15 hours ago, Jarin said:

No problem. I'll go figure out procedural wings in the meantime. Never used it before, myself.

Here you go @Jarin. I removed the procedural wings, so you don't have to worry about those. 

First spaceplane (bad, immense drag from cargo bays, can't go supersonic): https://dl.dropboxusercontent.com/u/46597246/Spaceplane-1.craft

Second spaceplane (good, little drag, easily breaks sound barrier): https://dl.dropboxusercontent.com/u/46597246/Spaceplane-2.craft

Edited February 1, 2017 by sh1pman