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[1.3.0] OPT Space Plane v2.0.1 - updated 29/07/2017


K.Yeon

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@JadeOfMaar I've been trying to use the J-92 Shcramjet in shcram mode, and I can't for the life of me figure out how fast I need it to go to get that mode to work. I have plenty of intake and plenty of power, but each time it tells me it's flamed out. Any hints?

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1 minute ago, AmpCat said:

@JadeOfMaar I've been trying to use the J-92 Shcramjet in shcram mode, and I can't for the life of me figure out how fast I need it to go to get that mode to work. I have plenty of intake and plenty of power, but each time it tells me it's flamed out. Any hints?

Shcramjet mode has Mach 3 as the flameout point and Mach 4 as the recommended minimum speed. It has and additional propellant requirement of EC.

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Whew. Thanks! I think I tried it but it made the flameout sound so I assume it shut down. This time I watched more carefully.

Also, in turbojet mode, it seems like the blue circle particle effects are going backwards, into the engine. Not sure if that's intended or not.

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I'm running 1.2.1. That's what the download link a few posts up is.

Well, backwards plume or no, I managed to put a rocket into Kerbol (note, the sun, not the planet) orbit with just a J-92. :)

Edited by AmpCat
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@JadeOfMaar, it's happened on every craft I've used it on. I'll get a shot of one and show you.

r597RAl.png

This happened even with using re-scale to make a smaller engine, and on all the craft I've used it on (at least 6 so far).

This example I used as short of a rocket as I could make so it's visible. That particular intake did not survive the extreme atmospheric heating caused by this velocity.

Edited by AmpCat
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2 hours ago, Apaseall said:

You know you have been playing too much when you right click and move your mouse to get a better view of a picture posted in these threads.

Totally done this many times.

@JadeOfMaar any idea why it's doing this now? I've made countless space planes with that engine over many years past, and I've seen those nice blue circles coming out the back before. It's not that big of a deal, mostly just curious.

Also, after playing with it further (staying up waaaaay too late) on getting it into shcram mode on a few different craft, it seems that by the time you're Mach 4, you're at the very end of usefulness in Kerbin's atmosphere, unless you really push extremes. I had to mount a thermal heatsink/mass behind my intake (don't remember which mod its from) to get the nose to survive such speeds. Not to mention a pretty shallow ascent out of the atmosphere, to get more than a few seconds in shcram mode. Think it might need to be tweaked a little to get more useful .. well, use out of the mode? Is it perhaps more useful in other atmospheres? Do we just need nosecones that can withstand much higher temperatures?

I really like using high performance turbojets, ramjets, turboramjets, etc. as 1st stages to rockets and space planes at mid-game and up, but I really had to put a lot of effort to even get to mach 4 before I was already well at enough energy for a circularization burn. Which really means the reduction of thrust in turbojet mode makes the engine just effectively nerfed. At least, for me. Could well be that I'm using it wrong. Or at least, not optimally.

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53 minutes ago, AmpCat said:

I really like using high performance turbojets, ramjets, turboramjets, etc.

Welcome to my world. :cool:

 

You're using the J-92 quite ineffectively. Its peak operating altitude is about 12km in Turbojet mode. I stay between 12km and 16km while building up for Shcramjet mode then I can cruise at altitudes under 30km at full throttle (maybe lower, depending on how insufficient the plane's intake capacity is), and under 38km (the limit for all jet engines) where I throttle back quite far and still steadily accelerate without worry of drag or overusing IntakeAir.

Before OPT Reconfig, you could easily get up to Mach 6 on just OPT's jet engines.

I never have to worry about an intake or anything behind it melting, only little things like external lights and control surfaces-- and (if using this combination) any OPT 2.5m cockpit and the J-2.5m adapter behind it. If you have any grasp on how fluid dynamics work, I'm betting your noses are prone to melting because they're not shielded from direct shock heating because they're too far (laterally/sideways) from the cockpit or other frontmost part and not in the cavity of air deflection.

The radiator mod you're speaking of is probably KSP Interstellar. Everything is involved with thermal mechanics there, and radiators come in countless shapes.

The J-92 may indeed be nerfed too far, but no one yet has complained so I left that alone. It cannot be used at all without Oxygen. That's where OPT Legacy and the OPT WarpJets come in. They don't need Oxygen (and don't even use LiquidFuel) but they demand nuclear reactors, some radiators, and much more intake capacity. They even let you SSTO from Eve.

Other Legacy engines also serve as all-range jet engines. The J-60 and J-61 liquid engines become scramjets (single mode) with Isp falloff and differing base Isp. The rocket engines there have Isp above 1000 (their internal nozzles or combustion chambers are really long, justifying it) but also demand EC (like the ARI-75).

Spoiler

This plane is easily moving at near Mach 8. For vacuum operation it has OPT Legacy's ARI-73 engine which uses LF only. 3x the thrust of the stock NTR, but no heavier than the ARI-75 LFO engine...however, it has no alternator.

M9JG5Q1.jpg

This plane too. J-92 and ARI-73 are a top-tier LF-only spaceplane engine combination.

s9088fz.jpg

 

WarpJets only. This plane can land in any atmo and return from it. (It has VTOL rocket engines from another mod).merzKw1.jpg

My long-time favorite spaceplane design. The NOX Crown. OPT Reconfig didn't exist yet so the Mk2 WarpJets here provide the Shcramjet mode. Also, this is in 2.5x where Mach 13 is my target velocity for orbital insertion burns. NOX for No Oxidizer.

eCs35IT.jpg

 

Edited by JadeOfMaar
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Ineffective in which way? Am I just way over-powering my craft? Like I said, for a vertical rocket (using J-92s for the first stage), I'm usually at an apo of over 100km by the time I'm mach 4, and on space-plane, I'm only 10 seconds or so from hitting 40km altitude. For a rocket, obviously I need a bit over a TWR of 1 (I tend to shoot for 1.5, but in the past I've noticed the J-92 can do well at basically exactly 1 or better.), and for a plane I try not to by much under 0.8. Maybe I'm just a bad plane designer. :)

I've been on a vertical SSTO kick the past while, mostly due to all the SpaceX excitement of late, but I'd really love to make a nice extra-planetary plane with atmosphere (but not oxygen) breathing engines some day. I've been pestering @Nertea for a nice atmosphere augmented nuke (basically a nuclear ramjet) for quite some time, to no avail. Looks like your updated engines fit the bill, though. Like you said, they're kinda like nuclear ramjets without a built-in reactor.

The radiator parts are the ERB-1000 or ERB-250 Heat Exchangers (from Kerb Kastra!). I was running into issues because on that particular build, the intake was the nose-cone of the rocket. The heat exchangers are not from Interstellar, since I don't use that one.

I spent most of last night trying to fiddle with something of a P-38 looking space-plane (1.25m body/pylons) with various OPT Reconfig engines. Still not settled on a design a like yet.

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@AmpCat Oh... In that way I can't give you any advice. There's no way you can use any jet engine effectively in a vertical craft. Horizontal velocity is crucial to them and you're wasting mass (and funds) in every sense with the steep ascent profiles required by vertical launch vehicles.

Kerb Kastra is one of Nertea's brands, therefore, you have the Heat Control mod.

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I use stage recovery and parachutes to get funds back, and I've found I can often do better with the very low fuel weight for the high ISP turbojets, than conventional rockets. I've not made a detailed, carefully controlled study yet, but try putting a couple J-61s on a 2.5m rocket. :)

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Back again. Small thing. My parts list is growing. Additional 'part = i.4m.cockpit.isp' are appearing. This is an old problem. I am working on my save files and thought I would bring it to your attention.

Spoiler

    SCENARIO
    {
        name = ResearchAndDevelopment
<snip>
        Tech
        {
            id = supersonicFlight
<snip>...
            part = i.4m.cockpit.isp
            part = i.4m.cockpit.isp
            part = i.4m.cockpit.isp
            part = i.4m.cockpit.isp
            part = i.4m.cockpit.isp
            part = i.4m.cockpit.isp
            part = i.4m.cockpit.isp
            part = i.4m.cockpit.isp
            part = i.4m.cockpit.isp
            part = i.4m.cockpit.isp
            part = i.4m.cockpit.isp
            part = i.4m.cockpit.isp
        }

 

1.

in \GameData\OPT\Parts\main\i_4m_cockpit_isp.cfg

Spoiler

//MODNAME: ORBIT PORTAL TECHNOLOGY SPACE PLANE PARTS
//VERSION: 1.9.9
//DATE_ED: 2017-07-29
PART
{
    name=i_4m_cockpit_isp
    author=K.Yeon
    module=Part
    
    //descriptions
    title=OPT 2.5m ISP Shuttle Cockpit
<snip>

    fuelCrossFeed=True
    
    vesselType=Plane
    MODEL
    {
        model=OPT/Parts/main/i_4m_cockpit_isp
    }
    node_stack_bottom=0.0, -1.63256, 0.0, 0.0, -1.0, 0.0, 4
    thermalMassModifier=5.0
    vesselType=Plane
    MODULE

2.

in \GameData\OPT_Legacy\Parts\MiscParts\Size_2\OPT_i_4m_cockpit_isp.cfg

Spoiler

PART
{
    // --- general parameters ---
    name=i_4m_cockpit_isp
    module=Part
    author=K.Yeon
    tags = opt size2
    
    
    // --- asset parameters ---
    scale = 1
    rescaleFactor = 1
    
    MODEL
    {
        model = OPT_Legacy/Parts/MiscParts/Size_2/OPT_i_4m_cockpit_isp
    }

    
    // --- node definitions ---
    node_stack_bottom = 0.0, -1.87819, 0.0, 0.0, -1.0, 0.0, 4

Ta.

Edited by Apaseall
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This explains the "part spam" in its node in the tech tree (I've seen it). Whenever more than one part config has the same part name that happens. It somehow never clicked to me to investigate this. :blush: 

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No worries. It has niggled my for ages. I just got a new bit of software, for another reason, AstroGrep. As you can guess Grep is the bit it does. It spat back a short list, and I told it to show me a few lines around the result. Easy once its done like most things.

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11 hours ago, Apaseall said:

Additional 'part = i.4m.cockpit.isp' are appearing.

I changed the part name to cure the problem and so the model towards the back (with a flag decal) appears. It's shorter, has extra windows, holds 5 kerbals (vs the known one and 3 kerbals) and has no IVA (while the known one has an IVA).

I'm going to test it with IVA and I'll likely keep it (because why not, they're nearly identical) and reduce the crew capacity to 3.

That's done. It checks out.

uRGzECy.jpg

I5vlEI8.png

Edited by JadeOfMaar
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3 hours ago, JadeOfMaar said:

I changed the part name to cure the problem and so the model towards the back (with a flag decal) appears. It's shorter, has extra windows, holds 5 kerbals (vs the known one and 3 kerbals) and has no IVA (while the known one has an IVA).

I'm going to test it with IVA and I'll likely keep it (because why not, they're nearly identical) and reduce the crew capacity to 3.

That's done. It checks out.

uRGzECy.jpg

I5vlEI8.png

Sorry didn't see this when I did my own investigation into my save file and tech tree getting additional copies of this cockpit. At least you name your cfg files in a rational way....making this an easy file search to track down the duplicate issue....

I wish everyone named their cfg files after the part name instead of something stupid....

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Like a computer, I get moody when people name stuff inconsistently. Thanks @JadeOfMaar for taking this issue on board, and for dealing with it so promptly. You are a credit to those that mod. I do try to provide as much info as I can, most of the time, when I comment on something that seems 'not quite right'. :)

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A question, where would I look to find out if a part inside a cargo bay is being shielded in terms of heat? I ask because I recently dropped into the utility section and found an arm. Long white and seems to be solely for space stations to handle erm stuff floating is space? I thought it looked like the one I seem to remember the space shuttle using. Anyway I added one for fun to the inside, I have some LFO tanks running along the lower sides of my cargo bays, of my cargo bay. Things get a little toasty during high altitude speed up for final tilt up for Kerbin escape to orbit. At a rating of only 900K the arms go poof! So I am wondering if they are not being shielded from heat properly?

Talking about heat, I think I remember a mod called BackInBlack that allowed cargo bays to be radiators. Now that would be awesome if you could implement. Button to turn on and off. Use Ec like other rads do. You see cargo bays are rather large. So they could be used for radiators. Sure their max temp would be limited. Meaning the surface area ability to radiate heat in space would be low. But this would be mitigated by the shear size of the cargo bay. Hence a none trivial amount of heat could be radiated away. No need to change the models. Just add the right radiator modules and there we go. I wonder what values to use? I am excited by the idea, how about you?

edit.

Talking about shielding, I added some spotlights. Inside some downwards opening cargo bays. To light up landing, VTOL using TCA. I am not sure but my space plane seems a little sluggish now. Possibly a bit more drag has appeared? These spotlights are not designed for this, they have a reasonable max temp so do not blowup, but they are not aerodynamic in the slightest. How would I check if the cargo bag is drag shielding them? Other than watching MechJeb like a hawk for aero drag?

Edited by Apaseall
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11 minutes ago, Apaseall said:

A question, where would I look to find out if a part inside a cargo bay is being shielded in terms of heat? I ask because I recently dropped into the utility section and found an arm. Long white and seems to be solely for space stations to handle erm stuff floating is space? I thought it looked like the one I seem to remember the space shuttle using. Anyway I added one for fun to the inside, I have some LFO tanks running along the lower sides of my cargo bays, of my cargo bay. Things get a little toasty during high altitude speed up for final tilt up for Kerbin escape to orbit. At a rating of only 900K the arms go poof! So I am wondering if they are not being shielded from heat properly?

Talking about heat, I think I remember a mod called BackInBlack that allowed cargo bays to be radiators. Now that would be awesome if you could implement. Button to turn on and off. Use Ec like other rads do. You see cargo bays are rather large. So they could be used for radiators. Sure their max temp would be limited. Meaning the surface area ability to radiate heat in space would be low. But this would be mitigated by the shear size of the cargo bay. Hence a none trivial amount of heat could be radiated away. No need to change the models. Just add the right radiator modules and there we go. I wonder what values to use? I am excited by the idea, how about you?

edit.

Talking about shielding, I added some spotlights. Inside some downwards opening cargo bays. To light up landing, VTOL using TCA. I am not sure but my space plane seems a little sluggish now. Possibly a bit more drag has appeared? These spotlights are not designed for this, they have a reasonable max temp so do not blowup, but they are not aerodynamic in the slightest. How would I check if the cargo bag is drag shielding them? Other than watching MechJeb like a hawk for aero drag?

I suppose I cheat because when anything like this annoys me I find the respective part configs and tweak them myself. I'd just tweak the arm's temp value to like 3000 or 4000 and then find the lights lower both their drag and angular drag to 0.1 or 0.0 and call it good.....lol. 

Little lights shouldn't be causing huge drag and robotic arms shouldn't be melting in the first place as far as I'm concerned....lol.

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Here are some numbers. The cargo bay, 306/313/1500/2700 core, skin, max, max. The fuel tank inside cargo bay that the arm is attached to, 303/265/200/2700. The arm, 228/766/900/900.

I will need to double check, but when I placed the arm, it looks like it is inside the cargo bay. No part of it was visible from outside of the cargo bay. No part of the arm clips the inner skin of the cargo bay.

Now yes I am at altitude, I am going rather fast. If the arm were to be attached externally to the craft then yes I would expect it to burn up. No question about that. But inside the cargo bay? The tank the arm is attached to is inside the cargo bay. That tank does not get very hot.

Lol. name = wbiSampleArm. WBI part it seems. With a name that erm does not reflect the in game name, title = Mk1 Station Arm. tut tut Angel-125 :) Joke. \GameData\WildBlueIndustries\001KerbalActuators\Parts\Utility\SampleArm\SampleArm.cfg.

So...if the tank does not get very hot, and the cargo bay does not get very hot, any idea why the arm does?

edit.

the cargo bay, name = kh.6m.cargo, spaceName = OPT KH Cargo Bay [CLS].

edit.

Yes I could make a small patch to change the temp of the arm. One more to change the drag. But I guess I would like the cargo bay itself to be examined to see if there is something that it should be doing that it is not. Or just be told - that is the crappy way KSP works, live with it! Lol. Joke.

Edited by Apaseall
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