Is it possible

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Vyssion
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Re: Is it possible

Post by Vyssion » Wed Jan 03, 2018 2:06 pm

As has been stated before, I would say that the air intake housed within the nose area of the car would probably be less efficient than what we have currently. The biggest issue I would think would be the proximity to the lead car's exhaust gasses... We already have an aero issue with following cars - do we want an engine one too?? :wtf: There is of course piping weight and loss of energy through the tubing due to wall effects etc as well to consider. Ram pressure id say would be minimal given the tubing's length through the chassis vs. its opening size - the cars are turbo powered anyways, so gain, any increase in pressure you would get from the ram effect would be overshadowed by the turbo compression. Besides, you could kinda argue we already get ram pressure effects with the roll hoop mounted solution; would mounting it lower actually do anything more? Id tend to think you would be stealing air from feeding the diffuser more than anything.

There are "holes" on the F1 nose already. Ferrari utilized a sort of "channel" to divert air upwards to the top side of the nose in a sort of "passive tangential blowing" to aid in the boundary layer structure. There are also other holes which are purely there to remove the boundary layer and promote a new one forming (look like little triangles).
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matt21
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Re: Is it possible

Post by matt21 » Fri Jan 05, 2018 4:50 pm

jjn9128 wrote:
Sun Dec 24, 2017 6:34 pm
As with everything else, the reason the engine air intake aperture is housed within the main roll hoop structure is that it is where the rules require it to be. Teams would rather move it, especially with forced induction engines (ram pressure is no longer necessary from the air horn as the turbo compresses the intake air beyond atmospheric pressure), to clean up the airflow to the rear wing.
The intake has not necessarily to be where it is at the moment.
The have to be between the cockpit front edge and 500mm before the rwcl, min. 200mm above the reference plane and on a plane parallel to C-C.

Why not using the intake as boundary layer removal device on the upper side of the side pod?

With Halo the intake air would be more turbulent I believe. And therefore the ram effect would be less efficient.

jjn9128
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Re: Is it possible

Post by jjn9128 » Fri Jan 05, 2018 10:11 pm

I think that would fall foul of the minimum 75mm radius and unbroken surface rules? The only apertures/openings allowed in the R75 volume is for suspension/drive shafts.

You'd probably be able to place them around the cooling inlets in the sidepod openings, but I'm not sure that's an advantage - it puts the ducting for the inlet air next to the radiators.

matt21
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Re: Is it possible

Post by matt21 » Fri Jan 05, 2018 11:43 pm

The intake(s) are specified in an explicit way. So I think they are legal as long as they are closed holes and not joined to the external surface.
Otherwise they could also not be whrre they are at the moment.

Example:
Take the rwo sauber inlets and shift them down and outboard. around. They would still have the same shape but be placed somewhere else.

jjn9128
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Re: Is it possible

Post by jjn9128 » Sat Jan 06, 2018 12:14 am

They can be where they are now because the R75 volume has an exclusion around the cockpit - it's why they can have the cooling louvres on the side of the cockpit. The opening also has to be fully visible from the front of the car without the driver or halo in place - so something similar to the Benneton posted earlier may be possible. So actually where I suggested - inside the sidepods, i.e. behind the suspension, may be a bit iffy legally.
Image
The cutout just below the camera on this image is abour where the Caterham inlets were.

roon
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Re: Is it possible

Post by roon » Sat Jan 06, 2018 12:44 am

Vyssion wrote:
Wed Jan 03, 2018 2:06 pm
As has been stated before, I would say that the air intake housed within the nose area of the car would probably be less efficient than what we have currently. The biggest issue I would think would be the proximity to the lead car's exhaust gasses... We already have an aero issue with following cars - do we want an engine one too?? :wtf: There is of course piping weight and loss of energy through the tubing due to wall effects etc as well to consider. Ram pressure id say would be minimal given the tubing's length through the chassis vs. its opening size - the cars are turbo powered anyways, so gain, any increase in pressure you would get from the ram effect would be overshadowed by the turbo compression. Besides, you could kinda argue we already get ram pressure effects with the roll hoop mounted solution; would mounting it lower actually do anything more? Id tend to think you would be stealing air from feeding the diffuser more than anything.

There are "holes" on the F1 nose already. Ferrari utilized a sort of "channel" to divert air upwards to the top side of the nose in a sort of "passive tangential blowing" to aid in the boundary layer structure. There are also other holes which are purely there to remove the boundary layer and promote a new one forming (look like little triangles).
The exhaust has a steep upward trajectory after the rear wing, following the general direction of the air moving through that region. Same for the radiator rejection. Look at photos where the wavy heat-distorted plume is visible. The exhaust in the wake is higher than the pipe exit, actually nearer to roll-hoop intake height. Same for the radiator rejection.

The strong vorticity in that region would aid in mixing ambient air with exhaust and radiator rejection. So what's left of the exhaust heat and its chemical-inertness may be neglible after a couple car lengths.

If not, then a lower, nose-level intake would actually be receiving the cooler, cleaner air below the aero-redirected exhaust plume. There's no heat coming out of the diffuser, these days. EBD days would have been a different story.

Vyssion
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Re: Is it possible

Post by Vyssion » Sat Jan 06, 2018 1:33 pm

roon wrote:
Sat Jan 06, 2018 12:44 am
The exhaust has a steep upward trajectory after the rear wing, following the general direction of the air moving through that region. Same for the radiator rejection. Look at photos where the wavy heat-distorted plume is visible. The exhaust in the wake is higher than the pipe exit, actually nearer to roll-hoop intake height. Same for the radiator rejection.

The strong vorticity in that region would aid in mixing ambient air with exhaust and radiator rejection. So what's left of the exhaust heat and its chemical-inertness may be neglible after a couple car lengths.

If not, then a lower, nose-level intake would actually be receiving the cooler, cleaner air below the aero-redirected exhaust plume. There's no heat coming out of the diffuser, these days. EBD days would have been a different story.
Id agree with you for the most part, yeah. But were talking about 350+km/hr whilst following less than a car length away at times during these overtakings - the air will of course have an upward trajectory, but there will not be enough time for that to make a noticeable difference in that situation.

Theres also the issue of rubber marble and gravel ingestion. I dread to think about what the intake would look like at the end of a race or when a car ploughs into the gravel traps and makes it out to continue racing at a partially blocked intake pace :shock:
If you can't explain it simply, then you don't understand it well enough.
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matt21
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Re: Is it possible

Post by matt21 » Sat Jan 06, 2018 1:58 pm

jjn9128 wrote:
Sat Jan 06, 2018 12:14 am
They can be where they are now because the R75 volume has an exclusion around the cockpit - it's why they can have the cooling louvres on the side of the cockpit.
But the Renault airbox is wider than the exclusion zone, isn't it? How does this then fit into the rules?
Image

jjn9128
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Re: Is it possible

Post by jjn9128 » Sat Jan 06, 2018 4:28 pm

matt21 wrote:
Sat Jan 06, 2018 1:58 pm
But the Renault airbox is wider than the exclusion zone, isn't it? How does this then fit into the rules?
I don't think it is - the cutout in the R75 above the drivers head is up to 125mm from the car centreline - i.e. a maximum airbox width of 250mm. The T-cam span is ~210 to 220mm, so I think they're under the maximum allowed width.
3.5.7 Bodywork shape (R75 rule)
Any vertical cross section of bodywork parallel to the plane C-C situated in the volumes defined below must form one tangent continuous curve on its external surface. This tangent continuous curve may not contain any radius less than 75mm:
a) The volume between 175mm forward of the rear wheel centre line and 300mm rearward of the plane C-C, which is more than 25mm from the car centre plane and more than 100mm above the reference plane.
b) The volume between 100mm and 300mm rearward of the plane C-C, which is more than 125mm from the car centre plane and more than 100mm above the reference plane.
c) The volume between 100mm rearward of the plane C-C and 300mm forward of the plane C-C, which is more than 390mm from the car centre plane and more than 100mm above the reference plane.
d) The volume between 100mm rearward of the plane C-C and 450mm forward of the plane C-C, which is more than 125mm from the car centre plane and more than 695mm above the reference plane.
e) The volume between 50mm and 175mm forward of the rear wheel centre line, which is more than 25mm from the car centre plane and more than 175mm above the reference plane.
The surfaces lying within these volumes, which are situated more than 55mm forward of the rear wheel centre line, must not contain any apertures (other than those permitted by Article 3.5.8 ) or contain any vertical surfaces which lie parallel to the plane C-C.
So a) allows the engine cover to to be up to 50mm thick - i.e. how Mercedes were able to have their sharkfin cooling outlet, b & d) is for the engine airbox, c) allows tighter radii around the cockpit headrest. The last stipulation is the most important for air intakes though.

roon
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Re: Is it possible

Post by roon » Sat Jan 06, 2018 11:40 pm

Vyssion wrote:
Sat Jan 06, 2018 1:33 pm
roon wrote:
Sat Jan 06, 2018 12:44 am
The exhaust has a steep upward trajectory after the rear wing, following the general direction of the air moving through that region. Same for the radiator rejection. Look at photos where the wavy heat-distorted plume is visible. The exhaust in the wake is higher than the pipe exit, actually nearer to roll-hoop intake height. Same for the radiator rejection.

The strong vorticity in that region would aid in mixing ambient air with exhaust and radiator rejection. So what's left of the exhaust heat and its chemical-inertness may be neglible after a couple car lengths.

If not, then a lower, nose-level intake would actually be receiving the cooler, cleaner air below the aero-redirected exhaust plume. There's no heat coming out of the diffuser, these days. EBD days would have been a different story.
Id agree with you for the most part, yeah. But were talking about 350+km/hr whilst following less than a car length away at times during these overtakings - the air will of course have an upward trajectory, but there will not be enough time for that to make a noticeable difference in that situation.

Theres also the issue of rubber marble and gravel ingestion. I dread to think about what the intake would look like at the end of a race or when a car ploughs into the gravel traps and makes it out to continue racing at a partially blocked intake pace :shock:
At 0 km/hr the exhaust plume exits higher than the tip of the nosecone at anywhere from a 0*-5* angle. In between the rear crash structure and the bottom of the rear wing, if it helps visualize. Note image below. Nosecone tip at approximately bottom edge of the wheel rim, exhaust at approx. the top tire sidewall. At 350+km/hr the plume will rise further along with flow in that region i.e. less than a car length, due to influences of the RW, monkey seat, diffuser, etc.

Image

Screening as with brake ducts and driver cooling ducts could solve foreign object injestion. Don't forget these engines also have an air filter. If small objects make it past the screen they would be caught by the filter. Detrimental to performance potentially, but not catastrophic.

jjn9128
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Re: Is it possible

Post by jjn9128 » Sun Jan 07, 2018 4:01 pm

At higher speed the vector of the exhaust plume will be flatter no? Engine exhaust isn't the only heat source on an F1 car, there's brakes running at an average of ~500C (peak >1000C), tyre surfaces are <100C, the cooling out flow will be 40-60C.

If nothing else I'd agree with the guy who works in the industry...

roon
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Re: Is it possible

Post by roon » Sun Jan 07, 2018 9:26 pm

jjn9128 wrote:
Sun Jan 07, 2018 4:01 pm
At higher speed the vector of the exhaust plume will be flatter no? Engine exhaust isn't the only heat source on an F1 car, there's brakes running at an average of ~500C (peak >1000C), tyre surfaces are <100C, the cooling out flow will be 40-60C.
It could be totally flat and it would still be higher than the nosecone tip. I discussed radiator rejection in a previous post. What would cause the exhaust plume to deflect downward at standstill or in motion, in order to intersect the nosecone tip? I'm not actually advocating for the idea, nor think that it's a particularly good idea. But the reasons posited in this thread against it aren't very strong.

An illustrative image:

Image

Smoke visualizes the radiator outflow. Flame visualizes the engine exhaust plume location.

Nosecone tip height is near the lower edge of the wheel rims i.e. below the top edge of the diffuser, even back when diffusers were shorter. It seems that some forum members say the exhaust and radiator plumes will deflect downward below diffuser height at certain speeds and conditions. If so, why?

jjn9128 wrote:
Sun Jan 07, 2018 4:01 pm
If nothing else I'd agree with the guy who works in the industry...
https://en.wikipedia.org/wiki/Appeal_to_accomplishment
https://en.wikipedia.org/wiki/Argument_from_authority

Vyssion
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Re: Is it possible

Post by Vyssion » Mon Jan 08, 2018 1:27 am

roon wrote:
Sun Jan 07, 2018 9:26 pm
It could be totally flat and it would still be higher than the nosecone tip. I discussed radiator rejection in a previous post. What would cause the exhaust plume to deflect downward at standstill or in motion, in order to intersect the nosecone tip? I'm not actually advocating for the idea, nor think that it's a particularly good idea. But the reasons posited in this thread against it aren't very strong.

Nosecone tip height is near the lower edge of the wheel rims i.e. below the top edge of the diffuser, even back when diffusers were shorter. It seems that some forum members say the exhaust and radiator plumes will deflect downward below diffuser height at certain speeds and conditions. If so, why?
I think there has been a few things meshed together and lost in translation somewhere. Yes, if we look at the nose cones, the exhaust exit is higher and so the natural tendency for the air to expand and rise due to its relative density, plus surrounding aero influences, would most likely keep a nose cone intake clear of that issue. However, it may not do so for the sidepod intake ideas which have also been stipulated within this thread.

That being said, there are parts on the F1 car which are almost completely worn away by gravel and dust from the racing, which need to be replaced race to race (i.e. front lower diffuser plate under the splitter below the nose). There is a lot of debris which does fly around, and whilst I'm sure that someone would be able to "manage" this, it wont be without some performance loss; whether permanent throughout the race or temporarily between pitstops or autonomous ejection or something.

Without me sitting down and running some sort of thermal CFD of a tandem "roll-hoop-intake" car setup and comparing it to a particulate suspension simulation with some amount of quantifying porosity over time for the "nose-cone-intake" setup, I can't say for sure which one would be "better".

My initial concerns with the original idea were exhaust gas management, debris and additional weight of all the piping with its associated dynamic pressure losses as air is bent and tunnelled to the engine. If exhaust gases are no longer an issue for the nose cone proposition, then by all means: my concern was misplaced in that case.

One thing I have heard from the drivers is that when they are following closely to cars, they will often complain that they can feel the exhaust heat blasting them before they pull out to pass - not exactly at nose cone height, but still quite low, relative to the typical CFD glyph plot you would look at showing a very sharp upward trajectory. (Whether they are at the bottom of the exhaust or the hot air hits the nosecone somewhere and follows the surface, I don't know)
If you can't explain it simply, then you don't understand it well enough.
- Albert Einstein


The great thing about facts is that they are true, whether or not you believe them.
- Neil deGrasse Tyson


Vyssion Scribd - Aerodynamics Papers