Aces High Bulletin Board
General Forums => Aces High General Discussion => Topic started by: Zoney on April 10, 2013, 03:41:16 PM
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or buffeting when behind another aircraft .
Is it modeled here? Is there a noticeable advantage from flying close and drafting another aircraft in real life ?
If it is not modeled here would you like to see it done?
I'm curious, in motorcycle roadracing it is a very bid deal. I have raced on the highbanks of Daytona and there it is everything.
Thank you in advance for your attention and replies.
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correct me if i am wrong,but wouldent "drafting" in a Aircraft cause the trailing plane to stall :headscratch:
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It would help to some degree but not directly behind. Much for much the same reasons migratory birds fly in formation to reduce fatigue.
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I've requested propwash be added in the past.
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I've requested propwash be added in the past.
:aok
One of the reasons for staggered bomber formations. That and defensive coverage.
(http://www.303rdbg.com/formation.jpg)
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I'm all for it but I don't think most people really comprehend how much of a bi!@# it'll be in our day to day AH-activities. I do think it would be good to add contrails and/ exhaust trails with such a feature, it will help and not just be eye-candy. It'll make taking off in groups much more difficult (and griping for a good 30-60 seconds at the heavy B-24s that just tookoff on your runway). Intercepting and escorting (or formation flying) along with B-29s will be a blast.
Ultimatley I think it's a bad idea because it's another hurdle for a new player to overcome, ontop of the challenge of finally sadling up that first fighter on fighter kill they now might get slaped in the face (by prob wash) during that last ("glorious") moment when they're lining up their first kill shot.... unless you wanted to encourage them to HO more, then maybe...
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So, you would rather encourage them (noobs) to attack from dead six on bombers?
Great idea! :rolleyes:
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I've requested propwash be added in the past.
This!!! For many reasons.
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well I learned this in groundschool a while back about wingtip vortices
http://cospilot.wordpress.com/2008/10/24/wingtip-vortices-and-wake-turbulence-explained/
kinda same but different :lol
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Its called "wake turbulance" and all planes make some.....Bigger the plane.....bigger the wake. Typically only swept wings create measurable wingtip votices.
If it were modelled it would tend to de-stabilize the "on six" aircraft. Suspect most would not like that.
With respect
<S>
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Typically only swept wings create measurable wingtip votices.
Just out of curiosity, where did you hear this?
- oldman
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The FAA is usually a very good place to start. Example: http://www.faa.gov/regulations_policies/orders_notices/index.cfm/go/document.information/documentID/1020684
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I've requested propwash be added in the past.
Why? Is your prop dirty? :bolt:
(It was just too good to pass up)
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The FAA is usually a very good place to start. Example: http://www.faa.gov/regulations_policies/orders_notices/index.cfm/go/document.information/documentID/1020684
The FAA is where I started, with AIM 7-3-3(a), for example:
"The strength of the vortex is governed by the
weight, speed, and shape of the wing of the generating
aircraft. The vortex characteristics of any given
aircraft can also be changed by extension of flaps or
other wing configuring devices as well as by change
in speed. However, as the basic factor is weight, the
vortex strength increases proportionately. Peak
vortex tangential speeds exceeding 300 feet per
second have been recorded. The greatest vortex
strength occurs when the generating aircraft is
HEAVY, CLEAN, and SLOW."
I've never heard that only swept-wing planes generate measurable vortices, and was just wondering what the source might be.
- oldman
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While in my world more physics=better game, I'd think wake turbulence would be extraordinarily processor heavy to model in any detail. Love the thought though.
Wiley.
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Typically only swept wings create measurable wingtip votices.
The B-24 and B-17 don't have swept wings but the vortice is enough to roll either of them. Been there in both types.
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Just out of curiosity, where did you hear this?
- oldman
33 years of experience on approach at busy airports
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It takes very little offset to stay clear of the wake. We got up within about 8-10 feet of the tail of the Liberator...nary a bump was felt.
(http://home.gci.net/~sncdfalk/bombpics/b24six.jpg)
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Dammit! Didn't you people watch Goose die in Topgun???
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If you are on a motorcycle and drafting, your ability to accelerate or maintain your current speed is not compromised from a loss of "thrust" because the rear wheel is still on the pavement and able to drive as hard as if there were no draft. If you were in an aircraft, drafting another aircraft, would the gain from the draft be offset by the loss of thrust because of the low pressure that is enabling your draft?
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If you are on a motorcycle and drafting, your ability to accelerate or maintain your current speed is not compromised from a loss of "thrust" because the rear wheel is still on the pavement and able to drive as hard as if there were no draft. If you were in an aircraft, drafting another aircraft, would the gain from the draft be offset by the loss of thrust because of the low pressure that is enabling your draft?
Drafting behind road vehicles is a completely different thing than wake turbulence in aircraft Zoney. Where vehicles have the ground effects, and ground traction - aircraft get turbulence and some aircraft creat such a huge wake (both in strength and linger/duration in the air for a time behind the a/c) that it will litteraly send another (ie: smaller) aircraft tumbling end over end if they unwittingly stray into it. Since the air is turbulent/choppy, it is not beneficial in any way that I can think of for flight. Think of a speed boat passing over a surface fo water that is nice and smooth or maybe 2" of waves/chop or maybe 2', or how about 20'?
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Thanks Babalonian, that's what I was afraid of. There is no advantage to draft in aircraft but is actually a disadvantage. <S>
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Wake turbulence after TO @ 1:06
http://youtu.be/nLAuJCqLyMk?t=1m2s
Wake Turublence before landing, this one is a good one, definetley strong and lingered long enough that you never even see in-frame the aircraft that made it.
http://www.youtube.com/watch?v=eblVIpdb1z8
This one is educational-ish, note in the description they mention they were trying to maintain the position, but the wake turbulence (from an = sized small a/c) would notabley fling them out to the right.
http://youtu.be/oBQZ8_NCbQU?t=1m38s
Thanks Babalonian, that's what I was afraid of. There is no advantage to draft in aircraft but is actually a disadvantage. <S>
NP I like the food for thought. I'm trying real hard to think of an advantage to the "persuer" and am drawing a blank. To the guy being chased though, it's definetley an advantage-card. Maybe deicing? :rolleyes:
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It's a little different with airplanes. A racecar's wheels provide enough lift to make the low pressure area behind the lead car not stall.
Would this be static lift or compression lift?
Race cars are also shaped in a manner that directs most airflow over the top of the car. This makes it a little harder for the atmosphere to fill in the low pressure area behind the race car because it happens from top to bottom instead of from all directions.
Vroom vroom Zoney <S>
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This one is educational-ish, note in the description they mention they were trying to maintain the position, but the wake turbulence (from an = sized small a/c) would notabley fling them out to the right.
http://youtu.be/oBQZ8_NCbQU?t=1m38s
Naw. Didn't "fling" them out to the right. Wing tip vortice rolls you, doesn't move you laterally. Vortice from the right wing would have rolled him left, not right.
Been in the wake of 182s and 206s a lot flying formation skydiving loads. It can be a bit unnerving at first but is controllable (but you might have to use a lot of control).
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The airplane wake I enjoy flying threw the most is my own.
HiTech
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That Liberator shot is awesome :)
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Zoney's question was a good one though and still has me thinking - since it is rather benenficial with some situations in the automotive world, is there any situation where wake turbulence could be of benefit with an aircraft? Then HiTech had to come outa left-field to remind us that all tractor prop aircraft naturally create their own before the aircraft follows, tuche.
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Color dubdub2 109 guncam footage with propwash from spitfire.
http://www.youtube.com/watch?v=kBm86lrCq2c
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Then HiTech had to come outa left-field to remind us that all tractor prop aircraft naturally create their own before the aircraft follows, tuche.
You sure he wasn't talking about flying an accurate figure? You can fly a circle and still feel your wake when you complete it.
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Zoney's question was a good one though and still has me thinking - since it is rather benenficial with some situations in the automotive world, is there any situation where wake turbulence could be of benefit with an aircraft? Then HiTech had to come outa left-field to remind us that all tractor prop aircraft naturally create their own before the aircraft follows, tuche.
I'm bettin Hitech is referring to flying thru his wake upon completion of a loop. Kind of like banging thru your wake as you do steep 720s
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is there any situation where wake turbulence could be of benefit with an aircraft?
Of course there is.
Ever see a flock of Geese? The same principles carry over.
http://www.nasa.gov/centers/dryden/news/NewsReleases/2003/03-42.html
http://www.nasa.gov/centers/dryden/news/NewsReleases/2001/01-77.html
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Motorcycles and cars drafting takes place in extremely close company. You watch Rossi and the like drafting the guy in front he is within a few feet, outside that the draught is broken. Not sure how it wouldd be beneficial here?
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It'd be nice, but modeling dynamic airflow apart from the flight model of the individual aircraft would likely require a fair bit of coad that could be devoted elsewhere to more effect. I've never seen turbies modeled quite like the real thing in a software program, to include the X-Plane series.
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Motorcycles and cars drafting takes place in extremely close company. You watch Rossi and the like drafting the guy in front he is within a few feet, outside that the draught is broken. Not sure how it wouldd be beneficial here?
Americans need to be educated on Rossi. He's like Michael Jordan and Dale #3 and Dick Butkus combined.
(http://www.carzi.com/wp-content/uploads/2008/06/valentino_rossi_helmet_05.jpg)
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Motorcycles and cars drafting takes place in extremely close company. You watch Rossi and the like drafting the guy in front he is within a few feet, outside that the draught is broken. Not sure how it wouldd be beneficial here?
Yes, the draft advantage is huge when you are within a few feet, but the higher the speed the greater the distance that some advantage is gained. At 200 mph I could feel and gain an advantage from about 40 to 50 feet. On a bike because you are out in the elements you can feel this low pressure pocket very well.
As you got closer you could feel it more and more until as you approached within a few feet you would have to perfectly time the moment you would break out of the draft and slip outside the slipstream and use this advantage for the pass. Nothing drove this lesson home as much as racing on the high banks of Daytona. Make the pass too soon and the rider you had just overtaken could pull back in your slipstream and use it to repass you.
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You sure he wasn't talking about flying an accurate figure? You can fly a circle and still feel your wake when you complete it.
Both would apply. Then the geese flying-V. All benefits to wake turbulence, so there's a few in given situations.
Of course there is.
Ever see a flock of Geese? The same principles carry over.
http://www.nasa.gov/centers/dryden/news/NewsReleases/2003/03-42.html
http://www.nasa.gov/centers/dryden/news/NewsReleases/2001/01-77.html
Aren't there a few other principles/physics still working against single-engine (or multi) prop-driven aircraft that aren't for geese, making it more difficult or less effecient? IE: prop-wash torque/spin (or whatever that term is). I believe there's more to a plane's wake (physics-wise) than a gooses, if im not mistaken.
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Both would apply. Then the geese flying-V. All benefits to wake turbulence, so there's a few in given situations.
Aren't there a few other principles/physics still working against single-engine (or multi) prop-driven aircraft that aren't for geese, making it more difficult or less effecient? IE: prop-wash torque/spin (or whatever that term is). I believe there's more to a plane's wake (physics-wise) than a gooses, if im not mistaken.
Obviously the geese benefit from drafting to some extent.
One thing I've found interesting is that when one of my birds overtakes a duck , pheasant, etc, it doesn't seem to be effected by turbulence to any level that I can detect. This applies both for falcons (which spend a fairly brief period, if at all, behind their quarry) and for accipiters, which get into some hair-raising, fast, tight-turning chases.
I would expect turbulence to be different simply due to the difference between propulsion methods of birds vs. aircraft. I also don't know of any planes that are quite as streamlined as a falcon (depending upon the birds flight configuration), although nothing is drafting off of them...
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Wouldn't the birds adjust their wing shape as soon as they feel turbulence?
Birds and aircraft both produce wing tip vortices and since the vortex is rotating it has an up side and a down side. The up side is to the outside. You can see that in the position of the geese in a V. They are aligned on the updraft of the wingtip vortices.
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I always thought the TT needed more drafting. Then I found Irish road racing. Either should astound any American.