Kerbomax Mainsail

[trekkie_]

[karolus10]

Actually, IMO this looks like a great 0.625 or 1.25 m engine. Something like a command/service module propulsion system?

Yeah, I would say that original model engine bell look far greater as 1.25m vacuum engine (heavier landers, service module) , maybe fatter and stronger competitor of LV-909... think about it .

Edited October 15, 2013 by karolus10

[trekkie_]

I noticed that if you look at KW rocketry, virtually all the bells are I think, exactly the same, regardless of engine type. just something I noticed when looking around for some proper shapes.

at 1.25m I wouldn't mind the original being a heavy lifting vacuum engine, whatever it looks like it suits best. but I'm still set on releasing at least 2 different style and configurations, that are at least worthwhile config wise to use.

I think what the model mostly reminds me of are the ones on the space shuttle.

Edited October 15, 2013 by trekkie_

[NathanKell]

Hmm, when I was going through KWR trying to class engines based on their nozzle, they looked different to me...

I mean, see the pics here. Don't the nozzles of the, for example, Vesta VR-1 and Wildcat V look a bit different? I mean, all rocket nozzles (other than altitude-correcting ones, obv) will look similar, but these have:

different area ratios

different throat:height ratios (Vesta is clearly longer for its throat width)

different curvature of the bell.

I really like the changes you've made, although I'd argue that the nozzle in that last pic, as a vacuum nozzle, would be best served by a 0.625m base. Vac nozzles are WAY bigger than SL nozzles, partly because SL nozzles (as you could see from the Wildcat/Vesta comparison above) are sometimes truncated vac nozzles with the curvature changed a bit.

Consider the Saturn V setup: the Apollo SPS (a class vac-optimized nozzle) had a nozzle about twice the width and length as the J-2, despite having only a fifth the thrust and weight. And the J-2 was mostly vac-optimized itself!

The F-1, the booster, optimized for mid-atmosphere work, had a nozzle only about 75% wider than the J-2, despite having about 20 times the thrust!

TL;DR: vac nozzles should be about 10x larger than their thrust would suggest.

We're kinda numbed to this because the engine bells on Squad's engines make NO sense.

[trekkie_]

Hmm, when I was going through KWR trying to class engines based on their nozzle, they looked different to me...

I mean, see the pics here. Don't the nozzles of the, for example, Vesta VR-1 and Wildcat V look a bit different? I mean, all rocket nozzles (other than altitude-correcting ones, obv) will look similar, but these have:

it would appear that way, but I think it's more visual trickery than anything else. what changes mostly is the color/pattern of ridges or other items on the throat and nozzle itself. but the bell shape never changes.

in fact, I did a blow up and overlay.....they match exactly. the curve of the bell is exactly the same on both the wildcat and vesta.

this is the vesta overlayed with some transparency on top of the wildcat...

Edited October 16, 2013 by trekkie_

[NathanKell]

Wishful thinking on my part I guess.

Blargh.

Then it's all on you, I guess! For doing right by vacuum nozzles...

Although the throat at least is properly narrower, you can see on the image, though the bell doesn't change. Which makes a little bit of sense, because there is an "optimal" bell shape...

c.f. here: http://www.pwrengineering.com/articles/nozzledesign.htm

[trekkie_]

that's sort of helpful, and similar. kw rocketry all seems to follow the RAO variety....but the only difference is the bell on KW is longer than in this graphic, with the curve essentially being the same as RAO.

Edited October 16, 2013 by trekkie_

[NathanKell]

Yeah, though some of the real low thrust/high Isp vac engines have a longer, slighter-curving nozzle closer to the ideal nozzle; I guess the drag losses are outweighed by other efficiency gains. Your vac-optimized engine had a nozzle that looked close to the ideal shape (as does, say, the RD-0146 with its nozzle extended, or the RL-10 with nozzle extender) I was suggesting something like that, but forgot that reference page until today.

[trekkie_]

mini aerospike just for fun. I shall call it the hornet

[TMS]

Some nice work in this thread. Love the spike. Cute!

[NathanKell]

Yup, cute is definitely the word!

[trekkie_]

just some numbers off the top of my head...

315 thrust

2.75 tons

310 atmo 420 vac

(basically an lvt45 and t30 in weight, minus 100 thrust, with slightly better efficiency. or a slightly heavier poodle but more thrust and better ISP)

maybe that can be for the other version though, because it actually more resembles a poodle.

still not sure whether to paint the skirt and what color....maybe a neutral one.

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I've been coming up with a name to call it, and something I came up with was the kerbomax (a pun on rockomax) segway or garrant. garrant, being a nautical term like "mainsail". and segway being descriptive of its in between capabilities (of course, it's actually spelled segue). probably all stupid lol.

Edited October 18, 2013 by trekkie_

[NoMrBond]

I love the detailing, butttt I'm not sure it should have the horizontal stringers looping the nozzle interior like that

I mean, outside you want all the reinforcing you can for strength and preventing deformation, or even flowing your coolant inside etc, but inside wouldn't that bugger up the exhaust flow?

Not like KSP actually processes that kind of thing, just the only thing that seemed a bit odd on the functional looking model otherwise

[Helix935]

is it ready for down load because i don't see a link

[trekkie_]

I love the detailing, butttt I'm not sure it should have the horizontal stringers looping the nozzle interior like that

I mean, outside you want all the reinforcing you can for strength and preventing deformation, or even flowing your coolant inside etc, but inside wouldn't that bugger up the exhaust flow?

Not like KSP actually processes that kind of thing, just the only thing that seemed a bit odd on the functional looking model otherwise

yeah it's hard to do that without making the thing too thick, or having to select the thousands of interior faces by hand and removing it. I use a separate simple low poly model for the interior, since the outside blocks have only an exterior face. it doubles as a collision mesh, since it's low poly. I could probably reduce that in size a little and it'll be smooth on the inside. that's why I'm in no hurry to release it, because there's still some polishing to do....and I've even been experimenting with some other details.

it is somewhat irrelevant though, after all this isn't based on any known engine like most are, and how often do people look up the tailpipe of their rockets?

I wish I could release mods quick, but I just don't have much time per day to tinker with making stuff and polishing it off, and some days no time. Plus I don't even really play the game anymore, I just make mods for it.....that makes it a little harder to come up with configs....not to mention with all the other engine part mods out there, you've got to make it fill a useful place without overlapping over the popular ones.

Edited October 18, 2013 by trekkie_

[NathanKell]

Huh, always knew them as gallants, rather than garrants. Learn something every day.

[trekkie_]

now available on KSP Port, reworked and tweaked to basic final version. second version soon to follow.

http://kerbalspaceprogram.com/kerbomax-galliant-lf-engine/

Edited October 20, 2013 by trekkie_

[Kerbal01]

Yays, can't wait to DL it( as soon as I get back on my regular laptop)

[astropapi1]

Yay!

Can your next engine be something between the Skipper and the Poodle? I'd do it, but my proudest archievement in Blender was making a textureless cilinder with a round-ish top.

[Psycix]

It annoys me to see a nozzle (albeit a nice looking one) without space for combustion chamber and turbopumps, yet being called an engine.

There is more to a rocket engine than just the nozzle.

Other than that, nice work. I also like the way you gave it a purpose in a balanced way.

[astropapi1]

Just here to report a typo in the description. georgous => gorgeous.

Awesome engine BTW.

[trekkie_]

It annoys me to see a nozzle (albeit a nice looking one) without space for combustion chamber and turbopumps, yet being called an engine.

There is more to a rocket engine than just the nozzle.

Other than that, nice work. I also like the way you gave it a purpose in a balanced way.

if you notice, the rockomax 48-7s looks very similar, with far less detail. that was unintended as I hadn't updated to the latest version including it until after I already came up with this. so the stock part should annoy you even more you have to consider though, that unlike many mods, this isn't based off of any actual engines in existence. it's much easier to find a picture of something someone already R&D'd then copy it. I was just going for a simple stock-alike

Edited October 20, 2013 by trekkie_

[Psycix]

if you notice, the rockomax 48-7s looks very similar, with far less detail.

Correct, and my opinion applies to that one as well

I think I'm just worried people get misinformed about how rockets work, while there are already enough of physics misconceptions in the world, so I guess I'll have to go yell at the KSP devs now.

But yeah, I guess it's just a pet peeve of mine.

If you ever feel like modeling a gas-generator+turbopumps with the same quality as this project, I'll be the first one to drool at it.

[trekkie_]

Correct, and my opinion applies to that one as well

I think I'm just worried people get misinformed about how rockets work, while there are already enough of physics misconceptions in the world, so I guess I'll have to go yell at the KSP devs now.

But yeah, I guess it's just a pet peeve of mine.

If you ever feel like modeling a gas-generator+turbopumps with the same quality as this project, I'll be the first one to drool at it.

it's hard because it's all been done before. virtually every actual rocket ever made in the real world (and even future ones) is out there somewhere for the game. virtually every shape and configuration of shapes and parts have been done. the only thing you can really do is make something more detailed and slightly different. and some of these things can be soo detailed that even being efficient with modeling, you're still looking at 10's of thousands of polygons. making engines in KSP is pretty difficult these days with the plethora of ones available, couple that with things like procedural fuel tanks and other stuff, and it's hard to even make other parts. that's why most newer mod releases are plugin based to add some new functionality. ksp has been around for years, and has had a pretty active modding community during all that time. in fact, it's probably one of the most active modding communities I've ever seen in most games.

I'm always happy to take feedback and let people participate in the modding process. I think it's nice for people to see their suggestions heard and even put into effect, which has always been a typical practice when I release mods. virtually every mod I've ever released, has had suggestions implemented.

if you've got something in mind for something more accurate you'd like to see, let me know. show me some pictures, etc.

[Tommygun]

I just imagine the rest of the engine is up inside the area of the fuel tank.

Many rockets have aerodynamic fairings covering the upper parts of the engines.