An arguement for a simple intake / jet engine tweak

[DundraL]

Hi, DundraL here. Still new to he community even though I've been playing a while. I've heard the next major patch is going to focus on spaceplanes/aeronautics so I figure now would be a good time for these suggestions. Anyway I'll just cut to the chase...

Quick version: Adjust Jet engine/ Intake weight

How- Reduce weight of every jet engine by 0.2-0.5 tons. Increase weight of every intake by that same amount.

Effect- Shifts weight forward on aircraft. better realism. game is more accessible for new guys. increases weight cost of airhogging. More variety in aircraft design.

This one change to a single stat on 7-10 parts can have a very positive effect, both in terms of realism, and accessibility for new players.

Seeing as how most aircraft tend to place jet engines towards the rear of the craft (crazy I know), and an intake somewhere infront of the engines, currently this means an unstable weight distribution for one of the heaviest subsystem that aircraft: propulsion. Why does this even matter? Because propulsion (and fuel) are the primary design elements that scale up with aircraft size. Unless you do something silly, your center of gravity is going to be way towards the back. This also means that a look around the forums will see the same aircraft shape over and over again: wings way back under the heavy engines, and everything else far forward, trying to balance out the weight of those engines, struggling to make a stable craft.

For beginners, the solution is to balance things out using the only other heavy thing that scales with an aircraft: fuel. This is a trap that will make planes inexplicably go out of control due to the heavy weight at the back becoming dominant once that fuel is burned. Payload? Just like fuel, it's temporary, leaving an unstable aircraft. For more advanced users, this is an engineering hurdle to be overcome with every aircraft.

But what else is there to balance the center of gravity? Extra cockpits and hab modules? Batteries? SAS? Keeping forward trim tanks full? This is just adding dead weight. Thats where the (heavier) intakes come in. Combined with lighter jet engines this would give users much more control over where their center of gravity is. Compressors in jet engines in real life are a major portion of their weight, so it definitely is more realistic. Worried about overall weight changes? Its the same weight for any 1:1 combination of intakes and engines. Also as a sidenote, this will also increase the weight of airhogging craft. I'm not sure this is an issue, as I personally see airhogging as an exploit, but your opinion may differ. Less airhogging is more realistic to me =P EDIT: Perhaps leaving 1 type of intake as is can allow those who like airhogging to continue to do so.

Considering that this change is litterally, a change to a single stat on 7-10 parts, it likely wouldn't require much time to implement. Probably more time discussing/testing it than implementing.

Also it is one of two perfect times to do this:

A: when overhauling spaceplane, users will likely redo many of their saved craft. You dont want to implement a change like his AFTER that, as that is the time it would interfere with gameplay the most. With the overhaul, users will be rebuilding craft anyway. Changing it during or just before a patch like this would minimize it.

B: when redoing flight physics. same reasons as above, but this IMO would be the second best time to implement this change.

Tell me what you think guys.

Edited title since it is no longer just before the spaceplane patch. As noted OP was written just before the economic boom patch, so keep that in mind if anything sounds crazy.

Edited June 5, 2015 by DundraL

[Wanderfound]

Not a bad idea, this. Simple, uncomplicated, trivial to implement, does the job. The only downside I see is that it would increase the need for canard-spamming on rear-delta designs.

Perhaps halve the increase in intake weight? That'd reduce the inevitable squealing from the airhoggers a bit, too.

[Kasuha]

Making intakes heavier without other adjustments is going to make planes even less stable. They have higher drag coefficient than other parts so they tend stay behind the CoM instead of in front of it. Making them ten times heavier will mean they turning force will be ten times stronger. Solution would be to reduce their drag.

Funny enough, radial intake which can and usually is placed in the back of the plane already has "standard" drag coefficient 0.2. I guess it wouldn't hurt to lower drag of circular/RAM intake as well and increase their mass.

[DundraL]

Making intakes heavier without other adjustments is going to make planes even less stable. They have higher drag coefficient than other parts so they tend stay behind the CoM instead of in front of it. Making them ten times heavier will mean they turning force will be ten times stronger. Solution would be to reduce their drag. Funny enough, radial intake which can and usually is placed in the back of the plane already has "standard" drag coefficient 0.2. I guess it wouldn't hurt to lower drag of circular/RAM intake as well and increase their mass.

Thats a good point. Seeing as how I only use FAR, I sometimes forget that stock aero model scales drag with mass for some reason. As you said, other intakes would also need to have their drag coefficient reduced to 0.2 in order to benefit stock aero models. Will update OP.

[Guest]

Just implement FAR as stock, please.

[ratchet freak]

Just implement FAR as stock, please.

can't happen without ferram giving explicit permission for squad to do so (licensing issues)

[Capt Snuggler]

taking the fuel mass out of the drag calculation would help too.

[Kasuha]

taking the fuel mass out of the drag calculation would help too.

I don't think it would mean and noticeable improvement for spaceplane stability and it would cause major stability problems for rockets.

[ratchet freak]

taking the fuel mass out of the drag calculation would help too.

like stock drag fix does?

[Capt Snuggler]

I don't think it would mean and noticeable improvement for spaceplane stability and it would cause major stability problems for rockets.

have you tried it? I have. it does give significant improvement to space plane handling, especially in reentry.

currently, transferring fuel forwards does not improve stability because you are also bringing your center of drag forwards with it. this leads for odd flips on reentry, where your delta wing space plane wants to go bum first despite being a nose heavy pointy thing.

By removing ResourceMass from the drag calculation this allows you to effectively stabilize your craft by way of the "weather vane" effect.

no negative effects to rockets in any of my tests. although I do tend to build my rockets "traditionally".

like stock drag fix does?

bingo

Edited September 16, 2014 by Capt Snuggler

[Majorjim!]

have you tried it? I have. it does give significant improvement to space plane handling, especially in reentry.

currently, transferring fuel forwards does not improve stability because you are also bringing your center of drag forwards with it. this leads for odd flips on reentry, where your delta wing space plane wants to go bum first despite being a nose heavy pointy thing.

By removing ResourceMass from the drag calculation this allows you to effectively stabilize your craft by way of the "weather vane" effect.

no negative effects to rockets in any of my tests. although I do tend to build my rockets "traditionally".

bingo

Snuggler is correct on this. I have seen the results of this fix. Planes handle much more realistically and the whole

drag depends on amount of fuel present is moronic. Its just silly and needs to be fixed.

The only drawback is that engines may need a nerf.

[Kegereneku]

I like that idea, simple stats change rather than new parts and new systems.

Maybe it could even lessen the need for a new aerdynamic model, I know there's a lot of fan of FAR & NEAR but if we need something balanced it must also be simple.

[Kasuha]

currently, transferring fuel forwards does not improve stability because you are also bringing your center of drag forwards with it. this leads for odd flips on reentry, where your delta wing space plane wants to go bum first despite being a nose heavy pointy thing.

The matter is to understand how stock drag model works. I'm not suggesting it's realistic, but it is deterministic and once you understand it, actually quite easy to use.

In my opinion, best way of building spaceplanes is the way where you don't need to transfer fuel to make them stable.

[Majorjim!]

The matter is to understand how stock drag model works. I'm not suggesting it's realistic, but it is deterministic and once you understand it, actually quite easy to use.

In my opinion, best way of building spaceplanes is the way where you don't need to transfer fuel to make them stable.

The Stock drag model doesn't work. Its totally broken. Calculating drag based on the contents of a fuel tank is just wrong and causes the kinds of problems that Snuggler suggested.

This is a FACT no amount of ignoring the argument will make it better Kasuha. The drag model is broken plain and simple.

What you seem to be suggesting is to just ignore the problem and build craft taking this very broken system into account. This is not a solution.

Imagine you go to the doc with a broken finger and all he said was "don't use that finger".

Not a sensible or intelligent suggestion.

[Capt Snuggler]

The matter is to understand how stock drag model works. I'm not suggesting it's realistic, but it is deterministic and once you understand it, actually quite easy to use.

In my opinion, best way of building spaceplanes is the way where you don't need to transfer fuel to make them stable.

people come in to the game with a basic understanding of how drag works, even if they don't realize it. they know what will happen if they throw a full balloon full of water and balloon full of air. they know what will happen if they throw a dart or paper airplane.

but then they are confronted with strange mystery forces that they cant account for. "my full tank is falling slower than my empty tank?" "my heavy nose pointy thing wants to fly backwards"

then the player has to come to the forums or delve into the code to discover that the aerodynamic model so far removed from reality that all their prior experience with paper airplanes darts is worthless. suddenly they're not playing the game they thought they where playing.

its just plain misleading.

[Laie]

The matter is to understand how stock drag model works. I'm not suggesting it's realistic, but it is deterministic and once you understand it, actually quite easy to use.

I'm not going all ferram over this, but I'd prefer if the stock aerodynamics would not grossly contradict everyday experience. Trying to build a streamlined rocket shouldn't be a bad thing. When your rocket explodes in mid-air, the falling debris should sort by weight and bulkiness (that's one of the first experiences in the game, after all). It doesn't have to be 100% right, mind you -- but halfways credible would be nice.

[Kasuha]

The Stock drag model doesn't work. Its totally broken. Calculating drag based on the contents of a fuel tank is just wrong and causes the kinds of problems that Snuggler suggested.

This is a FACT no amount of ignoring the argument will make it better Kasuha. The drag model is broken plain and simple.

What you seem to be suggesting is to just ignore the problem and build craft taking this very broken system into account. This is not a solution.

You know, there are two ways how to play a game.

One is to come to it with some idea how it should work, and then cry and swear and ask for fixing it because it does not work according to that idea. That's obviously what you do.

The other way is to come and figure out how it actually works, then use this knowledge to have fun. That's what I do.

Stock drag model works perfectly fine, regardless whether you like it or not. It is not realistic. Duh. There's almost nothing realistic in KSP wherever you go into detail. KSP is a game and is still in development. I'm not going to be crying or swearing when devs come and change drag model into something more realistis. Actually I will probably like it. But until they do, I'm fine with the drag model as it is.

Please realize that what you're trying to put as "FACT" is just your opinion. There is no rule how physics in a game should work. It's always up to developers to decide. For players, the game is the rule.

[ratchet freak]

You know, there are two ways how to play a game.

One is to come to it with some idea how it should work, and then cry and swear and ask for fixing it because it does not work according to that idea. That's obviously what you do.

The other way is to come and figure out how it actually works, then use this knowledge to have fun. That's what I do.

Stock drag model works perfectly fine, regardless whether you like it or not. It is not realistic. Duh. There's almost nothing realistic in KSP wherever you go into detail. KSP is a game and is still in development. I'm not going to be crying or swearing when devs come and change drag model into something more realistis. Actually I will probably like it. But until they do, I'm fine with the drag model as it is.

Please realize that what you're trying to put as "FACT" is just your opinion. There is no rule how physics in a game should work. It's always up to developers to decide. For players, the game is the rule.

but would you like an upgraded drag model that ignored mass of the part?

[pellinor]

Nice small solution, well explained. I'd love to see the quickfix in the next game version.

[Red Iron Crown]

I need to put this in my signature or something:

Fully-fledged, Physics-based Flight Simulation ensures everything will fly (and crash) as it should.

From here.

Clearly the game is meant to be a somewhat accurate simulation of reality, the aero model falls down in this respect. Hopefully they'll improve it at some point.

[Majorjim!]

You know, there are two ways how to play a game.

One is to come to it with some idea how it should work, and then cry and swear and ask for fixing it because it does not work according to that idea. That's obviously what you do.

The other way is to come and figure out how it actually works, then use this knowledge to have fun. That's what I do.

Stock drag model works perfectly fine, regardless whether you like it or not. It is not realistic. Duh. There's almost nothing realistic in KSP wherever you go into detail. KSP is a game and is still in development. I'm not going to be crying or swearing when devs come and change drag model into something more realistis. Actually I will probably like it. But until they do, I'm fine with the drag model as it is.

Please realize that what you're trying to put as "FACT" is just your opinion. There is no rule how physics in a game should work. It's always up to developers to decide. For players, the game is the rule.

Nobody is crying and swearing mate..

The game should not have counter intuitive features. We are all aware that KSP is not a full simulation but elements such as drag based on contents are clearly

errors that should be fixed.

The aero model will be fixed soon so it makes sense to point these things out. What could you possibly have against that?

You really should try the fix that snuggler is talking about. Its like night and day.

[Starwaster]

I don't think it would mean and noticeable improvement for spaceplane stability and it would cause major stability problems for rockets.

Have you tried it? SDF. In my sig does just that. Keep angle of attack 5-10 degrees and you're fine.

I haven't noticed major ill effects on planes either.

And playing around with intakes as suggested doesn't make a lot of sense. How is it realistic? Shift engine COM if you think it needs to be forward.

[Andrew Hansen]

I need to put this in my signature or something:

From here. "Fully-fledged, Physics-based Flight Simulation ensures everything will fly (and crash) as it should."

Clearly the game is meant to be a somewhat accurate simulation of reality, the aero model falls down in this respect. Hopefully they'll improve it at some point.

Yes, this is why many people buy KSP - because it's supposed to be realistic. I agree that this simple fix the OP mentioned should go into 0.25. A full aerodynamics revamp would be a lot of work and can come later, but this simple fix would fit in so perfectly with a spaceplane parts overhaul.

[Sean Mirrsen]

The intake suggestion actually makes quite a lot of sense. I was suggesting it - not quite in this manner, though - for quite some time now.

It makes sense for two reasons, to me. First is subjective, one I think would plug up (to a point) something I consider abuse of the existing model. Giving more of the mass to the intake, in the intake-engine pair, will mean that the fairly ridiculous practice of airhogging will at least be in some way penalized.

Second is objective, and comes in from a realism standpoint. Right now KSP abstracts away one of the four important pieces of a jet engine. We have the intake that lets air in, the exhaust turbine that pushes air out, and maybe the combustion chamber squished away in the too-short engine part somewhere, but no compressor turbine that allows real jets to function.

Notice how there's at least as much stuff in the front of a real turbojet, as there is in the back. The intake part in KSP could weigh as much as the engine itself, and it would still be realistic - in mass, if not size. Even if KSP isn't going to recreate the exact usefulness of compressors, giving the intakes a little more bulk and mass to at least pretend they are there would be quite logical.

[Nemrav]

Until there's a complete redo of the aerodynamics model, I think the added "-fuel weight" (aprox 3 words in code needed to be added(or removed if its to be cleaner)) and some weight balance is quite worth it.

If people want something really realistic, we could make the air compressor a completely separate part. and give it a bunch of the weight. Then with the jet split in 3 parts, we could have wackier designs....