New Safety enchancing device: Wheel Spray deflectors

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Just_a_fan
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Re: New Safety enchancing device: Wheel Spray deflectors

Post by Just_a_fan » Tue Sep 19, 2017 10:18 am

flynfrog wrote:
Tue Sep 19, 2017 1:47 am
Just_a_fan wrote:
Mon Sep 18, 2017 2:42 pm
Nice picture; proves nothing. Aircraft have wheels and, in that case, big engines that lift water off the surface. The wings aren't doing it.

F1 tyres each lift 25 litres / 65 litres per second (inter / full wet). That's 100 litres to 260 litres per second per car. That's a bath tub full of water each second. That's where the spray comes from.
I think its pretty clear in those pictures that the wings can and do have an effect. Look at the plume coming from the diffuser on the car and from the wing tips (well out side of the engine exhaust plume) on the plane. I am pretty sure wings that can provide 5g of df or lift a jumbo off the ground have more than enough effect to lift some water mist.
The diffuser lifts the wake from the tyres because the overall flow immediately behind the car is inwards and then upwards. Tyre lifts water, the wake pulls water in and up. For the front wing or diffuser to lift water off the ground it would have to overcome the surface tension of the water film. The nose of the plank would do this as it touches the ground but that's about it.

As previously stated, the full wet lifts 260 l/s. At 85m/s (about 300km/h), that equates to just over 3 litres of water per metre travelled. Or 15 litres per car length. That's a lot of water and that's why the spray is like a fog behind the cars.

Go and watch road cars driving in the rain. No downforce produced but lots of spray. That's at 1/3 of the speed with tyres that are much narrower and are enclosed in wheel arches.

The aircraft is taking off - the wings will often create a condensation wake in those high humidity conditions.
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PlatinumZealot
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Re: New Safety enchancing device: Wheel Spray deflectors

Post by PlatinumZealot » Tue Sep 19, 2017 9:53 pm

flynfrog wrote:
Mon Sep 18, 2017 2:07 pm
Just_a_fan wrote:
Mon Sep 18, 2017 1:45 pm
The tyres create the spray which is then lifted by the diffuser and rear wing. Not sure the floor or front wing create spray except when touch the ground.
http://www.aero-news.net/images/content ... -0116a.JPG
That is from the engine mostly. The engine blows the water off the runway.
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PlatinumZealot
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Re: New Safety enchancing device: Wheel Spray deflectors

Post by PlatinumZealot » Tue Sep 19, 2017 10:05 pm

I think this is a good place to start the design process.
Sort of the basics of how wet tyres work.

Last edited by PlatinumZealot on Wed Sep 20, 2017 10:01 pm, edited 1 time in total.
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bill shoe
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Re: New Safety enchancing device: Wheel Spray deflectors

Post by bill shoe » Wed Sep 20, 2017 9:16 am

Large trucks have lots of tires and therefore lots of spray potential.

DAF (and maybe other euro truck companies) use spray suppression fenders. It's a full wrap-around fender like this-
Image
The inside surface is covered with brush-type texture like this-
Image
Hard spray off the tires sticks to the brush-surface and flows down rather than splashing off and going back into the air.

Here's a report on spray suppression for heavy trucks--
https://www.aaafoundation.org/sites/def ... hSpray.pdf

Fenders could potentially cause F1 cars to lose the open-wheel look and end up like this-
Image

But it might be possible to package the fenders tightly around the wheels like a traditional sportscar fender in order to maintain the open-wheel look. Like this but with fenders around the entire wheel perimeter-
Image

It surely wouldn't look any worse than this safety device-
Image

If you've never raced in rain then you probably don't really understand how totally and completely vision can be lost. There are times when you can see absolutely nothing outside your car other than spray. It's interesting to drive around a track based on other senses (sound, vibration feel, timing) but definitely dangerous.

Just_a_fan
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Re: New Safety enchancing device: Wheel Spray deflectors

Post by Just_a_fan » Wed Sep 20, 2017 10:22 am

The simplest way to reduce spray is to require the circuits to use porous tarmac. The obvious downside is cost to the circuits. Other issues: what about where the circuit is a street circuit; the longevity of the tarmac when exposed to high-g cars.
Turbo says "Dumpster sounds so much more classy. It's the diamond of the cesspools."

johnny comelately
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Re: New Safety enchancing device: Wheel Spray deflectors

Post by johnny comelately » Wed Sep 20, 2017 10:36 am

Bill, here in Australia in the 90's someone designed something similar for trucks to reduce that danger from spray and it required national rules to make mandatory but some of the states would not agree and hence it never came into being as standard. it was only something like $15 - $18 per wheel by memory. go figure.
bill shoe wrote:
Wed Sep 20, 2017 9:16 am
Large trucks have lots of tires and therefore lots of spray potential.

DAF (and maybe other euro truck companies) use spray suppression fenders. It's a full wrap-around fender like this-
http://www.daf.com/~/media/images/daf%2 ... .jpg?w=480
The inside surface is covered with brush-type texture like this-
http://www.erturkplastik.com/image/cata ... ispray.jpg
Hard spray off the tires sticks to the brush-surface and flows down rather than splashing off and going back into the air.

Here's a report on spray suppression for heavy trucks--
https://www.aaafoundation.org/sites/def ... hSpray.pdf

Fenders could potentially cause F1 cars to lose the open-wheel look and end up like this-
http://hanabi.autoweek.com/sites/defaul ... k=XA7rLV4U

But it might be possible to package the fenders tightly around the wheels like a traditional sportscar fender in order to maintain the open-wheel look. Like this but with fenders around the entire wheel perimeter-
http://www.autoviva.com/img/photos/899/ ... _56899.jpg

It surely wouldn't look any worse than this safety device-
http://i2.cdn.cnn.com/cnnnext/dam/asset ... ge-169.jpg

If you've never raced in rain then you probably don't really understand how totally and completely vision can be lost. There are times when you can see absolutely nothing outside your car other than spray. It's interesting to drive around a track based on other senses (sound, vibration feel, timing) but definitely dangerous.

notsofast
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Re: New Safety enchancing device: Wheel Spray deflectors

Post by notsofast » Wed Sep 20, 2017 11:39 am

Perhaps it is possible to design rear fenders that can be bolted on fairly quickly, so that they need to be attached only when wet tyres are used. Pit stops would be slightly slower, but it would impact all teams in the same way. Teams could use the opportunity to switch to a wet-weather nose at the same time, if that were to improve performance.

zonk
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Re: New Safety enchancing device: Wheel Spray deflectors

Post by zonk » Wed Sep 20, 2017 1:10 pm

Remember those?
Image

nokivasara
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Re: New Safety enchancing device: Wheel Spray deflectors

Post by nokivasara » Wed Sep 20, 2017 8:01 pm

I think deflectors are the wrong way to go, the amount of water at the track does not change, the amount of water lifted by the tires does not change, so there's the same amount of water that gets moved around...

Better draining of the tracks shouldn't be that difficult, corners are banked and only need a "sewer" system that transports the water away. The straights maybe could have more rounded profile (camber?) so the water runs to the sides where it can be collected and led away.
Whatever it takes to make racing in the wet possible is better than the situation we have now, with SC or red flags as soon as there is some rain.

PlatinumZealot
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Re: New Safety enchancing device: Wheel Spray deflectors

Post by PlatinumZealot » Wed Sep 20, 2017 10:04 pm

bill shoe wrote:
Wed Sep 20, 2017 9:16 am
Large trucks have lots of tires and therefore lots of spray potential.

DAF (and maybe other euro truck companies) use spray suppression fenders. It's a full wrap-around fender like this-
http://www.daf.com/~/media/images/daf%2 ... .jpg?w=480
The inside surface is covered with brush-type texture like this-
http://www.erturkplastik.com/image/cata ... ispray.jpg
Hard spray off the tires sticks to the brush-surface and flows down rather than splashing off and going back into the air.

Here's a report on spray suppression for heavy trucks--
https://www.aaafoundation.org/sites/def ... hSpray.pdf

Fenders could potentially cause F1 cars to lose the open-wheel look and end up like this-
http://hanabi.autoweek.com/sites/defaul ... k=XA7rLV4U

But it might be possible to package the fenders tightly around the wheels like a traditional sportscar fender in order to maintain the open-wheel look. Like this but with fenders around the entire wheel perimeter-
http://www.autoviva.com/img/photos/899/ ... _56899.jpg

It surely wouldn't look any worse than this safety device-
http://i2.cdn.cnn.com/cnnnext/dam/asset ... ge-169.jpg

If you've never raced in rain then you probably don't really understand how totally and completely vision can be lost. There are times when you can see absolutely nothing outside your car other than spray. It's interesting to drive around a track based on other senses (sound, vibration feel, timing) but definitely dangerous.
Open wheeled is one of the requirements in my original proposal. So anything looking like a fender is ruled out. Fenders would be quite the easy solution though. For an open wheeled device it would need an understanding of the trajectory of the water as it leaves the F1 tyre... Remember it may only have to stop some of the spray, not all of it to improve driver vision.
"Raindrops .. drop top!"

PlatinumZealot
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Re: New Safety enchancing device: Wheel Spray deflectors

Post by PlatinumZealot » Wed Sep 20, 2017 10:10 pm

nokivasara wrote:
Wed Sep 20, 2017 8:01 pm
I think deflectors are the wrong way to go, the amount of water at the track does not change, the amount of water lifted by the tires does not change, so there's the same amount of water that gets moved around...

Better draining of the tracks shouldn't be that difficult, corners are banked and only need a "sewer" system that transports the water away. The straights maybe could have more rounded profile (camber?) so the water runs to the sides where it can be collected and led away.
Whatever it takes to make racing in the wet possible is better than the situation we have now, with SC or red flags as soon as there is some rain.
The topic is not about draining of the tracks though. :wink:

This topic is about engineering a fender-less solution to deflect the spray in order to improve driver vision down the track.
"Raindrops .. drop top!"

dodds_turbo
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Re: New Safety enchancing device: Wheel Spray deflectors

Post by dodds_turbo » Thu Sep 21, 2017 11:08 am

PlatinumZealot wrote:
Wed Sep 20, 2017 10:10 pm
nokivasara wrote:
Wed Sep 20, 2017 8:01 pm
I think deflectors are the wrong way to go, the amount of water at the track does not change, the amount of water lifted by the tires does not change, so there's the same amount of water that gets moved around...

Better draining of the tracks shouldn't be that difficult, corners are banked and only need a "sewer" system that transports the water away. The straights maybe could have more rounded profile (camber?) so the water runs to the sides where it can be collected and led away.
Whatever it takes to make racing in the wet possible is better than the situation we have now, with SC or red flags as soon as there is some rain.
The topic is not about draining of the tracks though. :wink:

This topic is about engineering a fender-less solution to deflect the spray in order to improve driver vision down the track.
Agreed, and as previoously mentioned I'm quite interested in what designs/concepts people come up with.

However the entire problem could be avoided by the use of proper drainage or permeable concrete, for example this concrete from TopMix:


PlatinumZealot
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Re: New Safety enchancing device: Wheel Spray deflectors

Post by PlatinumZealot » Fri Sep 22, 2017 10:24 pm

Yes. I am aware of that solution. It has been posted many times before... it has been beaten to death. As far back as 2010. Check the forum, thank you. However, this thread is about engineering the novel idea that is Fender-less spray deflection to improve driver vision in the wet Note that the post is made in the aerodynamics chassis and tyres section - Not the race tracks section.
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SectorOne
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Re: New Safety enchancing device: Wheel Spray deflectors

Post by SectorOne » Sat Sep 23, 2017 8:23 am

flynfrog wrote:
Tue Sep 19, 2017 1:47 am
I think its pretty clear in those pictures that the wings can and do have an effect. Look at the plume coming from the diffuser on the car and from the wing tips (well out side of the engine exhaust plume) on the plane. I am pretty sure wings that can provide 5g of df or lift a jumbo off the ground have more than enough effect to lift some water mist.
Yes. One can also think about the fact that in Monaco they weld the manhole covers shut for a reason.
A little bit of water is not an issue for a diffuser/rear wing to send straight up in the air.
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Edax
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Re: New Safety enchancing device: Wheel Spray deflectors

Post by Edax » Sat Sep 23, 2017 12:30 pm

PlatinumZealot wrote:
Wed Sep 20, 2017 10:10 pm

The topic is not about draining of the tracks though. :wink:

This topic is about engineering a fender-less solution to deflect the spray in order to improve driver vision down the track.
During brasil last year I got the impression that the visibility is getting worse. I took some time looking at old footage, but it is hard to say something conclusive without having the same footage from the same camera on the same track and conditions.

But i can well imagine that the advances in drag to downforce ratio leads to a less energetic wake. It seems like the old barn doors would throw up the water a lot higher than current designs, where it lingers behind the car, and most of it resettles on track.

I think you can go two ways towards this challenge. One is to artificially force it back on the track, but I'm afraid that will involve fenders.

The other way is to disperse it as much as possible and get it as high as possibe, where the wind can pick it up and remove it. Advantage is that a pack of cars can clear more water from the track, and can run in worse conditions.