about ground effect

[ROGER_elevensun]

i dont feel any ground effect aft i flare...is just me or not setup ground effect on this game for take off and landing yet?

i take 3 times finally adapt this landing but not smooth like when i fly real one 

but all other i feel good about it..IL2 is my frst sim game i like it

if anyting i say wrong plz give me some tip and teach me how to play this game

 

 

[FlatSpinMan]

I don't know, man.

What do you fly in real life, btw?

[DD_bongodriver]

Ground effect is difficult to simulate, they don't even do it properly in professional simulators.

[FlatSpinMan]

I only recall the name. Didn't the original IL2 have something about it? Maybe that was wave effect?

[ROGER_elevensun]

I don't know, man.

What do you fly in real life, btw?

CJ-6 J-7 SU27 now 737 800

[DD_bongodriver]

Su27 or J-11?

[ROGER_elevensun]

FlatSpinMan, on 14 Dec 2013 - 18:21, said:

FlatSpinMan, on 14 Dec 2013 - 18:21, said:

 

I only recall the name. Didn't the original IL2 have something about it? Maybe that was wave effect?

When an aircraft is flying at an altitude(aft you flare)that is approximately at or below the same distance as the aircraft's wingspanrotor diameter,This is caused primarily by the ground interrupting the wingtip vortices and downwashbehind the wing. When a wing is flown very close to the ground, wingtip vortices are unable to form effectively due to the obstruction of the ground. The result is lower ;induced drag, which increases the ;speedand lift of the aircraft.

DD_bongodriver, on 14 Dec 2013 - 18:27, said:

 

Su27 or J-11?

 At the beginning...we don;t have J-11 but aft they change the engine and aloting...J-11 come out

[ROGER_elevensun]

maby i just sucks on this game landing .......i get jump alot   coz i ways feel that flare attitude will make me run out litte ..

[FlatSpinMan]

Su27? Yep, okay, that's fairly awesome. Congrats!

CJ-6 - is that some variant on a Yak? I've seen that somewhere before.

 

Anyway, ground effect... um, yes. Still nothing helpful to add.

[DD_bongodriver]

Cj-6 is built by Nanchang loosely based on the Yak-52

[LizLemon]

I only recall the name. Didn't the original IL2 have something about it? Maybe that was wave effect?

 

Yes, both Il2 and Clod model ground effect.

 

The solution they use is pretty simple but gives results that are a pretty good approximation.

[Quax]

Both IL2 and CloD are so far away from the real thing, when it comes to landing, that it is not worth to think about their "ground effect"  

[LLv34_Flanker]

S!

 

 Modelling all the aerodynamical effects in high fidelity would make the sim unplayable due insane CPU power needed for that. I think the overall feel of the FM is more important than going too deep into the aeromystics  

[arjisme]

I bet the devs could figure out a way to model something reasonable without having to model "all of the aerodynamical effects in high fidelity" and suffer the consequent cost in CPU overload.

[DD_bongodriver]

Well they haven't bothered modelling the 109's instability on the ground handling, I guess because it has little relevance to combat, so ground effect is probably low on the list.

[Sternjaeger]

I'm still waiting for the blasted iMac to be delivered, but I thought I could feel the ground effect on the first two weeks? Did I imagine it then? 

[DD_bongodriver]

probably, I'm still surprised to hear it's modelled in IL2 and CoD, never felt anything that resembled proper ground effect.

[AndyHill]

I've only really felt the ground effect in DCS when flying the helicopters - probably where the said effect is most prominent. I don't know how realistic it is, however, if someone wants to pay for my chopper licence I can report back on the realism once I get some stick time.

 

Like was said earlier, it should be possible to approximate the effect reasonably without hogging all the available CPU. It's also a somewhat significant effect as far as flying the planes properly goes so it really should be there. Now the question is is it and if it is, is it realistic? I thought I felt something like a ground effect on some landings, but it might have been just me ballooning the plane slightly before touchdown.

[AndyJWest]

It is definitely modelled in IL-2 '46 - though not entirely correctly. I did a fair bit of investigation of this with the prototype autopilot system I wrote. The easiest way to demonstrate it without special software is to set up a jet in a very shallow hands-off descent over water (IL-2 jets tend to be more stable in this sort of situation). If you get it right, it will 'bounce' off the ground effect - a metre or so above the surface - before dropping back down and hitting the water. I suspect that the increased lift is modelled, but not the corresponding reduction in drag. 

 

Edit - link to original thread: http://forums.ubi.com/showthread.php/294158-Ground-Effect

Edited December 14, 2013 by AndyJWest

[LizLemon]

It is definitely modelled in IL-2 '46 - though not entirely correctly. I did a fair bit of investigation of this with the prototype autopilot system I wrote. The easiest way to demonstrate it without special software is to set up a jet in a very shallow hands-off descent over water (IL-2 jets tend to be more stable in this sort of situation). If you get it right, it will 'bounce' off the ground effect - a metre or so above the surface - before dropping back down and hitting the water. I suspect that the increased lift is modelled, but not the corresponding reduction in drag. 

 

Edit - link to original thread: http://forums.ubi.com/showthread.php/294158-Ground-Effect

 

Clod models both the lift increase and drag reduction, not sure about Il2.

[andyw248]

So beyond doing shallow hands-off descends over water, what indications of ground effect would we normally expect when flying a low-wing fighter? Maybe the following ones?

• Fly a normal approach in a LaGG, with MP maybe around 30, flare at an altitude lower than the wingspan but don't reduce MP (as you would to let it settle down); just leave MP where it is. Does the plane maintain its altitude, and keeps gliding down the runway? If yes, for how long? 
• Do the same at a higher altitude, maybe 100 meters above the runway, with the same configurations. Will the plane still maintain its altitude? For the same duration? Or will it start settling down because a lack of ground effect?

[LizLemon]

 

So beyond doing shallow hands-off descends over water, what indications of ground effect would we normally expect when flying a low-wing fighter? Maybe the following ones?

• Fly a normal approach in a LaGG, with MP maybe around 30, flare at an altitude lower than the wingspan but don't reduce MP (as you would to let it settle down); just leave MP where it is. Does the plane maintain its altitude, and keeps gliding down the runway? If yes, for how long? 
• Do the same at a higher altitude, maybe 100 meters above the runway, with the same configurations. Will the plane still maintain its altitude? For the same duration? Or will it start settling down because a lack of ground effect?

 

 

Ground effect should only be noticeable at an altitude equal to the wingspan. 

 

It most obviously manifests itself as an increase in speed for the same given engine power.

[Sternjaeger]

Ground effect should only be noticeable at an altitude equal to the wingspan. 

 

It most obviously manifests itself as an increase in speed for the same given engine power.

 

exactly, that's why I thought I could "feel" it last time I flew.. if memory serves I managed to do it only with the 109 though.

[andyw248]

Ground effect should only be noticeable at an altitude equal to the wingspan. 

 

It most obviously manifests itself as an increase in speed for the same given engine power.

 

Ok, the precise wording would be: "at an altitude equal or lower than the wingspan".

 

Right, if you fly at a constant altitude it should be an increase in speed; if you come from a descent it should amplify the flare (both assuming given engine power).

[AndyJWest]

Note that 'over water' is only relevant in as much it is easier to do tests over a level surface. 

[ROGER_elevensun]

I'm still waiting for the blasted iMac to be delivered, but I thought I could feel the ground effect on the first two weeks? Did I imagine it then? 

 

 

i think we both know "if without the ground effect we just fly to the runway...not touch to the runway.". i don;t know you get it what i mean or not..my english poor sorry about that...

yes we still can land but..just feel not right...is not the land i expct..or i nomal doing..or maby just i am still not good at game..i don;t know..that is why i tryed asking round.

 

 

for right now i think the bast way to doing a nice landing is useing power aft flare to equalize the GE make more life..and stall the plane touch the runway..for 109 i use 220 approach  power set 26% 3 dg gulie slop flaps useing all the way down befro i touch

 

i could wrong..so give me someting or what you guys doing..how you guys landed~

 

BTW game is great..i i real injoy play ..just A little greedy want more good

Edited December 15, 2013 by elevensun

[M4rgaux]

i could wrong..so give me someting or what you guys doing..how you guys landed~

 

I actually crash the plane on the runway... There's some nice ground effect ^.^"

[Quax]

Ground Effect in BoS:

 

 

http://www.youtube.com/watch?v=BDZ7VoBy1zA&feature=youtu.be

[Sternjaeger]

you can't tell if it's ground effect kicking in unless you're in the aircraft and can see your airspeed and throttle setting though..

[DD_bongodriver]

it is all pointless, there is no way to tell if ground effect is being experienced from an external view.

[Sternjaeger]

I know.  But you can compare the two vids. And if in the real one there is a big ground effect, which is missing in BoS, you should see the difference. Otherwise it´s all pointless. 

Both landings are done with power idle. And I don´t see any difference. That´s all.

 

As soon as you are out of speed, and the stick is full back, you will fall. No ground effect will kick in to soften anything.

 

Well yes, but you don't always get ground effect mate, you need some throttle to get ground effect.

Edited December 15, 2013 by Sternjaeger

[DD_bongodriver]

 

 

 

Well yes, but you don't always get ground effect mate, you need some throttle to get ground effect.

 

 

Not really, even gliders can get ground effect.

[DD_bongodriver]

there is only ground effect to be experienced, if you have speed left (as it doesn´t give you any lift, it just reduces the induced drag, which is only a small part of the whole drag). In that case the flare goes a bit longer, than without. But don´t forget, that there are other effects, much stronger than the ground effect, which can counter it.

 

From an external view it is impossible to tell if the pilot has simply held off in the flare.

Edited December 15, 2013 by Rama

[Sternjaeger]

Not really, even gliders can get ground effect.

 

yes bongo, but we're not talking gliders here, are we? Come on mate.. 

[Sternjaeger]

If you compare the vids now, you see there is no ground effect in both of them. The title of my vid was just "ironic". 

 

Quax, I'm sorry but that doesn't make sense, you can't tell if ground effect is happening if you don't have a reading of airspeed and throttle setting.

 

Ground effect can last a second or 15, it depends on how you follow up with your controls.

Edited December 15, 2013 by Sternjaeger

[DD_bongodriver]

yes bongo, but we're not talking gliders here, are we? Come on mate.. 

 

Don't get you, ground effect is not a function of power.

 

you didn´t get my explanation. Sorry, i can´t help you any further. 

 

I'm perfectly happy with my own understanding of the effect, have been flying for over 20 years, I didn't ask for help but thanks.

[Sternjaeger]

Don't get you, ground effect is not a function of power.

 

mate, we're talking about fixed wing aircraft, and ground effect on fixed wing aircraft is also affected by what throttle setting you have.

 

If you come down at idle but fast, you'll develop a bit of ground effect, which will dissipate quick as drag slows you down. If you come down with a bit of throttle and fast, you might be able to sustain ground effect all the way down the runway. 

[Sternjaeger]

Quax, what you're saying is correct only in part. 

 

You can come down for landing, flare and still be fast enough to "slide" into ground effect. 

 

And when you're on ground effect, your airspeed increases whilst you keep the same throttle and pitch setting.

[DD_bongodriver]

mate, we're talking about fixed wing aircraft, and ground effect on fixed wing aircraft is also affected by what throttle setting you have.

 

If you come down at idle but fast, you'll develop a bit of ground effect, which will dissipate quick as drag slows you down. If you come down with a bit of throttle and fast, you might be able to sustain ground effect all the way down the runway. 

 

A glider 'is' a fixed wing aircraft

[Sternjaeger]

A glider 'is' a fixed wing aircraft

 

Bongo, aren't you getting a bit pernickety now? 

 

Gliders have extremely efficient wings, but don't generate thrust, and the ground effect behaviour is slightly different, so I don't think their behaviour pertains to the observation of low wing, fixed wing, propeller driven, aircraft. 

Edited December 15, 2013 by Sternjaeger