Galane

Does KSP model ground effect aerodynamics?

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Gaarst is succinct, but also correct. KSP's aerodynamics are not that detailed. 

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In other words a ground effect style vehicle could be built but would require some mod to maintain height above terrain in order to fake it, and there wouldn't be the drag reduction effect that a WIG experiences.

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KSP doesn't model aerodynamics at all.

It's just some lookalike half done twisted version of some airy/soupy goo that is actually a particle dynamics substitute that gives enough vague resemblance to allow people to utter the word aerodynamics during a full exhale.

Not sure if the FAR mod adds this, or whether it's possible to mod these dynamics into the game. I do hope so :)  

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1 hour ago, Helmetman said:

KSP doesn't model aerodynamics at all.

It's just some lookalike half done twisted version of some airy/soupy goo that is actually a particle dynamics substitute that gives enough vague resemblance to allow people to utter the word aerodynamics during a full exhale.

Not sure if the FAR mod adds this, or whether it's possible to mod these dynamics into the game. I do hope so :)  

Before 1.0 the air was even more soupy. The aerodynamics in 1.0 are a bit more realistic than before.

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The Feram changelog doesn't include the word "ground" or "ground effects", I don't expect it to model such things but does anybody know for sure?

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10 hours ago, Helmetman said:

KSP doesn't model aerodynamics at all.

It's just some lookalike half done twisted version of some airy/soupy goo that is actually a particle dynamics substitute that gives enough vague resemblance to allow people to utter the word aerodynamics during a full exhale.

Not sure if the FAR mod adds this, or whether it's possible to mod these dynamics into the game. I do hope so :)  

KSP does model aerodynamics. Unfortunately it almost entirely only contains Newtonian laws. It's missing Bernoulli's Principle and a 3rd item on which things like fluid dynamics and ground effect would function. Adding those things would make KSP's CPU requirements skyrocket but if I'm right, a little magic could be done that requires a little extra math, and the KSPWheel API (and this is just for ground effect. I'm not going near fluid dynamics)

Edited by JadeOfMaar

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There is a mod that adds altitude holding. Doesn't work if there are no engines pointing down. Needs to be able to read the terrain and adjust flight controls appropriately.

A WIG plane gets reduced drag at altitudes up to 50% of its wingspan. How about a ground effect mod that adds a little box part to attach to a plane? When attached it reduces the drag and limits altitude to 1/2 the maximum width of the craft, while also additionally faking the effect by incorporating terrain following. There's plenty of info on the web on calculating the effects of ground effect on drag.

 

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2 hours ago, wumpus said:

does anybody know for sure?

Yes. The answer is "No". ferram4 has mentioned the lack of ground effects in FAR many times.

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1 hour ago, Galane said:

There is a mod that adds altitude holding. Doesn't work if there are no engines pointing down. Needs to be able to read the terrain and adjust flight controls appropriately.

A WIG plane gets reduced drag at altitudes up to 50% of its wingspan. How about a ground effect mod that adds a little box part to attach to a plane? When attached it reduces the drag and limits altitude to 1/2 the maximum width of the craft, while also additionally faking the effect by incorporating terrain following. There's plenty of info on the web on calculating the effects of ground effect on drag.

 

Are you asking for someone to make that mod for you? If so, you're asking in the wrong place. You should ask in the mods section of the forum. Also, you can ask all you want, but don't get your hopes up that someone will come along to make a mod for you. That being said, you should consider making the mod you want; while it's unlikely that someone will just make the thing you're asking for, the community is pretty good when it comes to helping people to make mods. Lastly, the mod you propose sounds like you just want to magic away the physics that the game is simulating. That's certainly an option, and it's the easiest way to see the results you want on the vessel(s) you have in mind, but it will likely result in very unrealistic and unexpected vessel behavior if that part is used in any way other than the one way you've designed it since it's defeating the actual physics the game is simulating. Also, forcing a vehicle to follow the terrain at a fixed height would likely just make that vehicle look like it is riding on the ground on tall, invisible wheels. Abrupt changes in the slope of the terrain would cause the vehicle to adjust height in a very unnatural way for a flying vehicle, and since all terrain in KSP is made with hard angles the only place you could use your mod without it looking and acting very strange would be over water.

Sorry if it seems like I'm being a total bummer. I'm not trying to just shut you down. WIG effects are very interesting, but simulating the effect is a bit more complicated than you describe if you want vessels to continue to work as expected. I think it can be done in an effective and functional way, but simulating WIG effect has such limited use in KSP that I'm not surprised that no one has done it yet.

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Don't listen to them, do it anyway. There's nothing like screaming over the wavetops at an altitude of 3 meters.

For when you want to circumnavigate the planet with 80 tons of munitions (WIP):

kNoQS5W.jpg

When you want to move half that mass, half that distance, and do it fast (WIP, the part count on the other was getting out of control): xMqifaI.jpg

I still have to add the cruise missile rails, and finish designing the micro-tanks, and micro-subs that go in them.

Between the batteries and the fuel cells, they can fire the seven lasers continuously for about 2.5 minutes. All aspect radar and sonar, and enough bombs and missiles to level a city.

In addition, they can handle being blown into pieces, and front, rear, and pontoons can still defend themselves independently from air, sea, and ground threats.

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3 hours ago, FleshJeb said:

Don't listen to them, do it anyway. There's nothing like screaming over the wavetops at an altitude of 3 meters.

For when you want to circumnavigate the planet with 80 tons of munitions (WIP):

kNoQS5W.jpg

When you want to move half that mass, half that distance, and do it fast (WIP, the part count on the other was getting out of control): xMqifaI.jpg

I still have to add the cruise missile rails, and finish designing the micro-tanks, and micro-subs that go in them.

Between the batteries and the fuel cells, they can fire the seven lasers continuously for about 2.5 minutes. All aspect radar and sonar, and enough bombs and missiles to level a city.

In addition, they can handle being blown into pieces, and front, rear, and pontoons can still defend themselves independently from air, sea, and ground threats.

What are the ball turrets on front? thinking of the airborne laser

Also if height depended on wingspan, would not long wings be better? 

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A WIG that only operates from water needs to be maneuverable when landed. Thus their wing aspect ratio tends to be wide and short, just long enough to make 1/2 the wingspan an acceptable altitude for the plane. You want pitch control to be quick enough so that if something causes it to nose down the pilot can pull it up before hitting the water.

That's likely where that baseball player got into trouble with his shiny new amphibious plane. Got into ground effect, skimming the water and pushed the stick forward or a wind gust picked the tail up. Destroyed the aircraft and himself.

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23 hours ago, magnemoe said:

What are the ball turrets on front? thinking of the airborne laser

Also if height depended on wingspan, would not long wings be better? 

Yes, those are the Airborne Lasers. from BD Armory Continued. They have a 60 m/s crash tolerance, and none of the stock nose cones are that good anymore. Also the PEW PEW PEW factor is cool.

What Galane said regarding the wings. Although I did it mostly for aesthetic and part limitation reasons. I also figure we're ramming a fair amount of air into that constrained box. Unfortunately blown wings don't work in post-1.0 aero. I fake it by having flaps on each wing segment.

 

21 hours ago, Galane said:

A WIG that only operates from water needs to be maneuverable when landed. Thus their wing aspect ratio tends to be wide and short, just long enough to make 1/2 the wingspan an acceptable altitude for the plane. You want pitch control to be quick enough so that if something causes it to nose down the pilot can pull it up before hitting the water.

That's likely where that baseball player got into trouble with his shiny new amphibious plane. Got into ground effect, skimming the water and pushed the stick forward or a wind gust picked the tail up. Destroyed the aircraft and himself.

Thanks for the info. I've always been curious about that disparity.

They're certainly a challenge to build and tune to get them to turn flat, as well as not being over-controlled so that they pitch into the water. I somersaulted the second one by digging the nose in a few days ago.

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