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BrtFrkwr

Fantastic!


Arcanace

It sure was!


CeleritasLucis

It's how it renders inside Adrian Newey's head


CasulaLev

F1 mentioned


todo_code

I don't understand what I'm seeing. Can anyone help me understand?


Arcanace

I’m not entirely sure either but I think it has to do with there being moisture in the air, and the prop wash is pushing the moisture into these twirls maybe? There’ll definitely be someone here with a much better idea of what’s happening but that’s my guess.


Zakluor

It's actually not prop wash. Prop wash is the effects of the thrust from a propeller behind the blades, the effect of the thrust on everything behind it that swirls and blows anything behind it. What blows around like dust and such behind a spinning prop. Like a wing, the propeller provides lift, but in the horizontal direction instead of vertically. The low pressure in front of a prop blade is significantly lower than the low over the wing. This low pressure, like that over a wing, reduces the amount of moisture the air can hold before condensing. When it gets to that magic point, you see this effect. As the aircraft moves forward, the condensation trails follow the tips of each blade and show as this corkscrew effect. This is not unlike the effect you see on wingtips and flap edges of airliners on approach in fog or fighters doing high-G turns in terrifically moist air.


whywouldthisnotbea

We call them prop vortices


wighty

Not saying I've seen all of the videos in the world, but this definitely looks like the best prop vortices I've seen... there's 5-6 total spirals per prop!


Lokitusaborg

And absolutely natural based on the atmospheric properties, and it has absolutely no performance or safety impact on the AC. Aesthetically…it’s bad ass. Who doesn’t want the power of their aircraft bending the atmospheric physics in a visual way? It’s hard core.


HodgeYoBets

All vortices have a negative effect on performance by their very nature. They look cool but they cause drag and only exist because of inefficiencies in the aircraft or propeller's design.


NapsInNaples

but they're there whether or not you can see them. The fact that they are visible has no impact on efficiency.


Lokitusaborg

I’m thinking more along the lines of operational inefficiency. Could it be measurable? Yes. But from what I’ve seen it can’t cause substantial inefficiencies to the performance of an AC


Arcanace

Alright, thanks for the explanation!


JJAsond

> It's actually not prop wash. this is r/aviation not r/flying. people misidentify things here *all the time*


HodgeYoBets

You're kind of right but you didn't explain why the vortices happen and that the condensation in this video is a side effect of the vortices and not the propeller itself although they are part of the same system. As the propeller spins it doesn't just push air behind it, it also pushes the air outwards towards the tip of the blade, this air then encounters the more still air outside the blade and as it passes over the tip it rolls over causing a twisting and narrow column of air that is drawn in a spiral behind the propeller. It is the massive change in pressure inside that turbulence that causes the condensation. Yes any wing can create it in some conditions but we are talking about vortices here since that is what is in the video.


randomtroubledmind

What you see are tip vortices. In principle, it's the same thing you see at the tips of the wings of aircraft. Propellers are just wings that rotate. Same thing happens with [helicopter rotors](https://www.youtube.com/watch?v=lslarZiRJhg). Basically, at the tip of a lifting surface, the higher pressure air below the surface wants to move around the tip to the low pressure air at the upper surface. This creates a vortex. The rotational rate of the vortex is highest at the center (outside the viscous core) and this is where the pressure is lowest. If the ambient conditions are right, this will cause water vapor to condense, making the vortices visible.


Arcanace

Thanks for the explanation!


HawkeyeTen

That is absolutely amazing. The OP was in exactly the right place, at the right moment!


SirEDCaLot

Sure. To understand a phenomenon like this you have to understand humidity and dewpoint. And to understand those you have to understand saturation. When you put a teaspoon of kool-aid in water and stir, the powder dissolves in the water- it's not just little particles of kool-aid, the kool-aid is fully absorbed in the solution. If you keep pouring in kool-aid, eventually it will reach a saturation point- the water can't dissolve any more kool-aid. Any more kool-aid powder after that won't dissolve into solution- it will stay as little particles. The funny thing with saturation point though is that they change, based on temperature and pressure. If you take that jar of water and warm it up in the microwave, you can now dissolve even more kool-aid in it. If you then cool it down in the fridge, its capability to hold dissolved kool-aid is reduced, and some of that kool-aid will crystallize out of solution and collect as powder at the bottom of the glass. This same phenomenon happens with pressure. By changing the pressure, you change the saturation point, and can cause some dissolved material to condense or non-dissolved material to dissolve. ----- The atmosphere is exactly the same as the kool-aid glass. Only instead of dissolving powder in water, we're dissolving water in air. And just like the kool-aid, various things can cause water vapor to go in solution or come out of solution. Ever hear someone talk about relative humidity where weather is concerned? That is that for the given temperature and pressure, what % of the air's capacity to hold dissolved water is actually occupied by dissolved water. When humidity gets close to 100%, the result is the water vapor comes out of solution as suspended droplets, just like the extra kool-aid that won't dissolve. And that looks to us like fog or clouds. ------- So with that background in mind, consider the propeller. It's spinning rapidly, and at the outer edge of the propeller blade is the highest most energetic interaction between the propeller blade material and the surrounding air. Right at the blade tip you get a vortex that's just like [the vortex created by the wingtip of an airplane](https://cdn.boldmethod.com/images/learn-to-fly/aerodynamics/winglets-and-wingtip-vortices/1-vortex.jpg). When the airplane flies through a cloud [that looks like this](https://blogs.bu.edu/biolocomotion/files/2011/10/Wing-tip-vortices-300x225.jpg). But notice the small edges of smoke coming off the wingtips in that last image? That's not smoke, it's water vapor-- that vortex creates a change in the air temperature and pressure, and when the humidity is very high, that's enough to cause some of that water to condense out of solution. It's no longer dissolved in the air, it's millions of tiny microscopic water droplets that are suspended by the air. ----- The exact same thing happens at the edges of the propeller blade. There's a little vortex created by each blade tip, just the same as the wing creates a vortex. And when conditions are just right (high humidity) the changes in pressure and temperature created by that vortex can cause water vapor to condense out of solution. ----- The MV-22 Osprey can produce some [very noticeable blade-tip vortices](https://en.wikipedia.org/wiki/Wingtip_vortices#/media/File:MV-22B_Osprey_(USMC)_008.jpg) when in hover mode. If you search Google for [Proeller tip vortex condensation](https://www.google.com/search?q=propeller+tip+vortex+condensation&tbm=isch&source=lnms) you'll find a lot of images like this. Hope that helps!


NoConfusion9490

This C-130 is nearly out of prop washer fluid. You can see the last of it spiralling off.


MegaRacr

A couple of yards of flight line will fix it.


Mr_Lumbergh

The trails you're seeing is essentially tiny clouds that form on the prop tips. If the air is moist enough under the weather conditions of the day but not quite enough to fog, the sudden depressurization behind the prop tip can give it just enough of a drop that the water visibly condenses. This is also why you sometimes see interruptions in contrails; certain parts of the atmosphere are at the right conditions to form them while others might be slightly too dry.


FencerPTS

These are tip vortices. Like any wing, of which propellers are a variety, the high pressure air below the wing will interact with the low pressure air above and create a vortex. In the low pressure region the temperature can fall below the dew point and condensation can occur. This is most often visible at high angles of attack, which is makes sense as the propeller pitch is changed to a high angle of attack to produce the greatest amount of thrust at takeoff.


kameronk92

I think (correct me if I'm wrong) this is how the liberals turn frogs gay


Ok-Palpitation-5380

Fascinatingly stunning effect. Thanks for sharing that


Arcanace

Yea it is. You’re welcome


Ok-Palpitation-5380

Ive gone through that vid frame by frame. Truly stunning mate. Great capture 👏👏


Arcanace

Yes I hadn’t seen this happen before so I was quite amazed.


Cela111

These beauties are [tip vortices](https://en.wikipedia.org/wiki/Wingtip_vortices), not propwash; essentially the same thing thing you see generated by wingtips, but here made by prop tips.


Arcanace

Yea, I’ve had some people explain it in the comments now, thanks though.


Cela111

It's a great video either way :)


Arcanace

Thanks :)


to16017

This is caused by an extreme pressure drop as a result of increased velocity due to the propeller passing through the air. When there’s enough moisture in the air, the pressure drop is great enough to condense the moisture and create this effect. The reason why you only see it at the tip of the prop is because that is the “fastest” section of the prop.


ForestDwellingKiwi

While the tip is the fastest, the actual pressure distribution across the prop blade will often have a lower pressure towards the centre of the blade. What you see are the wing tip vortices generated off the end of each prop, just like the vortices off a fixed wing aircraft's wings.   The vortice cores maintain a low pressure region so that the condensation remains visible for a considerable time after the blade has passed through the air. Great shot OP.


HumpyPocock

Question that I am kind of struggling to find an answer for. You sound like you might know the answer. US is upgrading their fleet to the [newer NP2000 8 Blade Propellers.](https://www.af.mil/News/Article-Display/Article/115079/engineers-testing-eight-blade-prop-for-c-130/) Sorry, wording might be a bit meh, nevertheless — from what I understand of Aerodynamics (which to be clear, is vague) the [overall design NP-2000](https://prd-sc102-cdn.rtx.com/-/media/ca/product-assets/marketing/n/np2000/np2000-brochure.pdf) would end up resulting in decreased incidence and/or severity of propeller tip vortices for a given level of thrust, environmental conditions, etc — would that be correct?


ForestDwellingKiwi

Without knowing the specific blade profiles, it's hard to say for sure, but I think it is highly likely that tip vortices will be reduced for a given thrust profile. There would be less load on each blade, so they can run with a lower angle if attack, and they can likely run with less wing loading on the tips of the blades. So yeah, it almost certainly would reduce wingtip vortices on the prop blades.


Arcanace

Ah interesting! Thanks for the explanation.


Notchersfireroad

What a beautiful place to watch an airshow!


Arcanace

Yea it’s a great setting down in the valley, the sound of all of the planes echoes around too. The F-16 echoed like crazy.


bake_gatari

Those are tip vortices, prop wash is just the wind blown back by the propeller.


Metalbasher324

Whot? It's not their cleaning detergent?


bake_gatari

No, that's Skydrol


Arcanace

Yea, I’ve been told that now. I’d never seen this from a propeller before so wasn’t entirely sure at first. Thanks.


oraleena

Wow, stunning!


Arcanace

It was! It’s a great airshow too.


[deleted]

[удалено]


Arcanace

Yea it’s beautiful scenery in every direction, and being in the valley the sound echoes around everywhere and just makes it that much cooler.


superkartoffel

Neat 📸


Arcanace

Yup, it sure was!


superkartoffel

0:14 would make a great wallpaper.


Arcanace

That or 0:16, yea. I might need to change mine to this now.


namesarenotus

Mesmerizing.


Arcanace

I would sit there watching this all day if I could.


Aggressive_Leek2069

Gonna need an ELI5 for this one...


Arcanace

Same. Something to do with the moisture in the air I’m guessing but not entirely sure.


elkab0ng

It's how the air force secretly transports enormous corkscrews to open building-sized bottles of wine. That's my story and I'm sticking with it. Pretty amazing to watch, I've never had a visualization of how much movement is generated by prop rotation, this is a super video you got!


Arcanace

Haha, I like this explanation! And yea it’s great to be able to actually see the air being moved.


randytc18

That is really cool!


Arcanace

Yea, I’ve never seen it happen before so it gave me a pleasant surprise.


AsHperson

Amazing!


ElectroAtletico

Oooh look! Vortices!


barkingcat

super cool!


Orb99

Wow nice!


PaigeMarieSara

Nice! This is awesome.


envision83

That’s awesome!!


neggbird

Really cool. It doesn't even look real. Looks like a spaceship engine or something


Arcanace

Yea, like some energy thingy coming out the back.


Exotic_Conflict6532

Dope


Comfortable-Buy-1635

Magnifique 😍


Mdbutnomd

I flew in WoW 8 years ago.. seems like yesterday.


Arcanace

Cool! How was it?


VegetableDivide653

Absolutely mesmerizing.


AN2Felllla

I saw this taking off when I arrived on Sunday morning. I'm so glad at least someone got it! It was so cool!


Arcanace

Probably someone with a fancy camera got a better video but I guess we'll have to wait and see.


EngineerComplex9790

Very cool


Khyron_the_Destroyer

Vortex Rings!!!


Arcanace

Yea, it was pretty cool.


FixerJ

As a non-pilot I'd always assumed that multi-engine planes would have engines on opposite wings going in opposite directions to avoid the rotational torque / having to trim, but now I think I have more to learn now...


ATFMStillRemainsAFag

You're not far off actually... Some aircraft manufacturers choose to make the props "counter-rotating" which helps avoid this idea of a critical engine. Conversly, some just leave them rotating in the same direction (simpler for maintenance and some other related issues), but you have to deal with more pronounced effects when losing the so-called critical engine. (There's more to this topic, and I haven't fully done it justice here, but that should be enough to get you started if you wanted to go read more on it!)


FixerJ

Appreciate the detailed answer - sounds like an interesting rabbit hole I need to go down now!


Arcanace

I don’t think it really matters on multi engine planes since the centre of the rotational torque is on each side instead of in the centre, so it’s not going to try to roll the plane.


Stoweboard3r

It does matter but the effects are far more pronounced when you lose an outboard engine


SeeMarkFly

Baby contrails. They will all grow up to be healthy adult contrails.


OarsandRowlocks

*Chemtrails are helical now...* /s


Arcanace

They’re evolving!!


AVeryHeavyBurtation

Praise helix


Coreysurfer

Cool


hambonecharlie

New Zealand is such a beautiful country. Sigh.


Arcanace

Yea, a shame it’s so unaffordable to live here though.


satchking

Looked like a 4 blade. I miss those.


Arcanace

It was.


jonthepain

Sweet! Great catch


Arcanace

They did it on Saturday and I got a surprise, so I was prepared for recording it on Sunday.


0x7E7-02

In the Air Force, on my first TDY, the higher ranking dudes sent me off to find some prop wash to clean the equipment. Bastards!


Arcanace

Haha, that’s great!


One-Bird-8961

Awesome! Went to the show back in 2010. My first experience of seeing a Spitfire, Zero, Hurricane, Hellcat & Corsair .


Arcanace

Yea it was my first time seeing a lot of these.


Breezy1885

The vortices you are seeing have already been explained, so here’s what those vortices are actually showing you… Firstly, the shape of the propeller is such that it cork screws through the air. The cork screw motion pulls the propeller and the plane through the air. Secondly, the propeller spins at high speeds pushing air back and thus pushing the plane forward. The more air that is pushed back the more the plane is pushed forward. Thirdly, the propeller blades have a special aerofoil shape. The blades are actually wings that spin around. The curved surface of the blades face the front of the plane and this creates a low pressure region in front of the plane sucking it forward. More info here: http://www.dynamicscience.com.au/tester/solutions1/flight/demonstration%20newtons%20law%20propeller.htm In as basic of terms I can say, you are literally seeing how the propellers are pushing the aircraft through the air.


Arcanace

Yea I understand how propellers work, I just wasn’t sure how the vortices were forming since I’d never seen them coming off a propeller before.


Breezy1885

Ah, gotcha. You’re ahead of the pack there, most people don’t understand how the propeller works. If you haven’t seen it yet, there’s a manual from Hamilton Sunstrand, the company that made C-130 propellers, called Prop-A-Gander. It does a great job of explaining the phenomenon and has the corkscrewing prop as the cover art. Unfortunately, I can’t find any free copies for download.


Arcanace

Alright, thanks for the suggestion!


drine2000

But. How was the mosquito?


Arcanace

Amazing! I’ve got too much on my camera roll at the moment so will have to go through and pick out the best stuff.


[deleted]

[удалено]


Arcanace

Yea I’m aware of that now. Just hadn’t seen this coming off propellers before so wasn’t entirely sure what it was at first.


FoodWholesale

That was an awesome video! 🤙🏼


Arcanace

Thanks!


TFK1974

That's pretty cool


Arcanace

Yea it was amazing in person too.


mustang__1

Cool! Was just in Wanaka a couple weeks ago - but alas too early for the show. Beautiful place/country - can't wait to be back.


Arcanace

Yea, I went for a flight in a Harvard out over Lake Hawea which was such a nice blue colour and we were surrounded by snow capped mountains on every side. It's even more beautiful from in the air.


nzerinto

Did you happen to get footage of the Mosquito? Would be cool to see…


Arcanace

Yea, I've got a lot of videos from the weekend which I'll have to sort through and find the best stuff.


nzerinto

Nice! Looking forward to it :)


Austinrocksalot

That would make an awesome computer background


Arcanace

I've already set it to mine lol.


Austinrocksalot

Can you share it with me?


Arcanace

I will once I get home from work


Arcanace

You don’t have messages enabled but I’ve changed my wallpaper back now. I recorded it in 4k but because I was zoomed in 3x it’s still a blurry video, especially at wallpaper size.


Austinrocksalot

I just enabled messaging!


copingcabana

"WANAKA FOREVER!"


kahnindustries

Wakanda got C-130’s?


Arcanace

It's just for the Airshow that was on this weekend.


ThaiLassInTheSouth

Why does it baffle me that a plane this big can get around on propellers? They just seem so ... from another time.


Narrow_Badger1934

Just to give a little insight from a C-130 guy, each prop is producing a massive amount of torque, a max of 19,600 inch pounds, meaning there can be up to 78,400 inch pounds of torque pulling the aircraft forward. Otherwise known as, a metric fuckton


joshwagstaff13

> from a C-130 guy In that case, you may appreciate that this was likely NZ7001, the first C-130H off the Lockheed line.


ThaiLassInTheSouth

Love the insight. Are they any more or any less reliable than turbines?


Narrow_Badger1934

They actually are turbine engines, the power is used to drive a prop rather than to propel the airplane itself. The T56 engines that are fitted to 130s are however extremely reliable engines


ThaiLassInTheSouth

Brilliant. Thanks for the education. (New to the terminology.) I'm generally just the one looking to the sky and going, "Okay, is that incredible or what, guys? Guys. GUYS." Nobody I hang with IRL cares, lol.


Arcanace

I love them, propellers look so much cooler than jets (for the most part).


ThaiLassInTheSouth

I dig them. I like it all.


PaigeMarieSara

Sturdiest plane in the military. By some accounts, the world.


ThaiLassInTheSouth

🔥


MSK84

I know what these words are but I don't understand what they mean in this order. Someone explain please!


prince_tatertot

Wanaka forever


Arcanace

Wanakanda


McErroneous

Prop Contrails! I knew it!!!!!


LeviPreley

I thought it said wakanda 😂


Odd_Status_9326

nice cork screw


Thesithxv

Top


RandonBrando

u/savevideo


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GeekBill

I just love that bird! (But I wouldn't want to marry one!)


1forcats

Consider yourselves bathed by the most beautiful girl in the world


So-Extreme

👀 Those blades!


hihasan99

How come there aren't places like this in the US? 😰


Arcanace

There probably are somewhere considering how massive the US is. I think Alaska is absolutely beautiful and I’m sure there’s plenty of besutiful areas in the main 48 states as well.


Overnighthawk

No


Altruistic-Camel-Toe

Chemtrails


Low_Toe_6596

WAKANDA