Williams FW36 Mercedes

[trinidefender]

[...]

Unfortunately they don't work like that. Air will still be pulled through the slot as a result of lower pressure above the sidepods and higher pressure in the ram air sidepod intake. The only way, that I can see at least, for your idea of diverting more cooling air at low speeds then at higher speeds having more air going through the slot would be with mover able aero which is obviously banned.

[...]

You mean air will be pushed through the slot, i.e. flow from inside the sidepod to outside the sidepod?

In any case, my view is that the slots probably help regulate pressure within the sidepod. If pressure is too high or too low, you get inefficient cooling and a lot of drag. If you get it just right, you get efficient cooling and the Meredith effect, i.e. an effectively drag-free sidepod.

The opening to the slot is ahead of the radiator so therefore the slot has no cooling function. Therefore as far as the slot I concerned the Meredith effect is irrelevant to it.

[trinidefender]

Too convoluted, there would always be a low pressure zone after the slot, air would always be pulled there, the only practical effect being to reduce the effective intake area.

Yes in this case the angle of attack is low over the front portion of the sidepods but remember as air accelerates over the top of the sidepod it produces lower pressure. At the same time inside the radiator intake there is a restriction that is the radiator and/or intercooler and whatever else. This means that there will be a greater than atmospheric pressure buildup in the radiator inlet. This pressure differential between the high pressure of the inside of the inlet and the low pressure of the top of the sidepods helps to drive air through the slot helping airflow to resist separation and turbulence on the outside of the sidepods.

I think Williams have actually come across quite a novel way of using slots to keep airflow attached, we shall see if they continue to use it. Most other teams have used slots by placing them actually on the top/front of the sidepods so the slot inlet is outside the radiator inlet but to my knowledge this is the first time this configuration has been used.

Yes Williams does sacrifice some cooling airflow but then again it does seem them introduced these slots with their new bodywork which does seem to be more "cooling intensive" for want of a better word.

[bhall]

The opening to the slot is ahead of the radiator so therefore the slot has no cooling function. Therefore as far as the slot I concerned the Meredith effect is irrelevant to it.

It's only physically in front of the radiator. If there's no direct link from the slot to the sidepod inlet anywhere in front of the radiator, then it is effectively behind the radiator, because the air flow it vents will have been heated by the radiator and pressurized by whatever flow structure that exists within the sidepod. In other words, it's essentially no different than this vent...



...it's just located elsewhere.

The slot/vent/whatever only showed up on the car after it was initially tested without one. So, it could be that slot/vent/whatever is a fix for a problem the team did not want to solve by changing the air flow patterns around the Coke bottle.

Given the apparent difficulty of judging sidepod air temperatures, and thus pressure, in light of the switch to a turbocharged engine with a single exhaust and the addition of batteries and tigers and bears - Red Bull and Renault have made a few headlines of late because of just that, well, not exactly that - it's not a particularly unlikely scenario. In my mind, it's certainly more plausible than the questionable benefit of preventing flow separation with an inherently draggy leading-edge slot.

[rjsa]

I'll put $50 that it's just a nask to contrict the air intakes. Just cooling air tunning that would be achived with new sidepod bevels in proper race situations.

[bhall]

What's a nask?

Otherwise, yeah, I generally agree that it's a fix of some sort. The leading-edge slot idea just doesn't work for me, because I think it amounts to an attempt to fight drag with drag.

Such logic usually only works in [insert relevant national legislative body here].

But, I've been wrong before...

EDIT: Yeah, I really think they're vents.

The vortex generators on last year's Toro Rosso would have been superfluous additions to the car if the components in question had functioned as true leading-edge slots.

[stefan_]

2014 Australian Grand Prix - Thursday, 13.03.2014

[Sevach]

Sidepod slot seems to be on the car.

And i'm not sure but i think the front brake duct is new.

[Sebp]

When did they drop their hollow front axle?

[Sevach]

Mid 2013.

I might be talking crap here, but is the suspension one of those passive hydraulic that Mercedes had last year?

[trinidefender]

The opening to the slot is ahead of the radiator so therefore the slot has no cooling function. Therefore as far as the slot I concerned the Meredith effect is irrelevant to it.

It's only physically in front of the radiator. If there's no direct link from the slot to the sidepod inlet anywhere in front of the radiator, then it is effectively behind the radiator, because the air flow it vents will have been heated by the radiator and pressurized by whatever flow structure that exists within the sidepod. In other words, it's essentially no different than this vent...

http://i.imgur.com/HSIiLUR.jpg

...it's just located elsewhere.

The slot/vent/whatever only showed up on the car after it was initially tested without one. So, it could be that slot/vent/whatever is a fix for a problem the team did not want to solve by changing the air flow patterns around the Coke bottle.

Given the apparent difficulty of judging sidepod air temperatures, and thus pressure, in light of the switch to a turbocharged engine with a single exhaust and the addition of batteries and tigers and bears - Red Bull and Renault have made a few headlines of late because of just that, well, not exactly that - it's not a particularly unlikely scenario. In my mind, it's certainly more plausible than the questionable benefit of preventing flow separation with an inherently draggy leading-edge slot.

How do you know the entrance to the slot is behind their radiator? If this is the case then the energy of the airflow will have been seriously reduced and the slot turns into a vent for hot air. I'm not saying this is impossible just that it is improbable.

The way I see it the entrance to the slot is in front of the radiator and therefore takes the higher pressure air from the radiator inlet (before the constriction that is the radiator).

They could have realised that there was airflow separation around the top of their coke bottle and as a result of that created the slot to fix that. Teams have been using slots and vortex generators for a while now to help control the airflow around the ever tighter coke bottles.. Remember the tighter the coke bottle, the more likely the airflow is going to stall because of larger angles.

Lastly why can toro rosso not have run a slot gap and vortex generators at the same time, they both do a similar job but in very different ways.

[bhall]

How do you know the entrance to the slot is behind their radiator? If this is the case then the energy of the airflow will have been seriously reduced and the slot turns into a vent for hot air. I'm not saying this is impossible just that it is improbable.

[...]

How is that improbable? The primary purpose of all sidepods is to be a vent for hot air. To say that performing its primary function is improbable is a bit like saying a steak probably shouldn't be eaten. I mean, I guess they'd make good doorstops, but they're much better when devoured, yanno?

Don't get me wrong here; I like the lateral thinking, because it's fun to ponder possibilities, and lord knows I've tossed around a few gems over the years. But, I just can't imagine an F1 engineer voluntarily adding a component with a highly questionable value for the intended application and that would nevertheless contribute to the problem it's meant to solve no matter how well it functions. Drag is drag regardless of origin.

But, as a vent for hot air? Absolutely.

Bad things happen...



...when teams don't....



...get that right.



(Luckily, it doesn't really matter if either one of us are right. If only engineers had such a luxury...)

[trinidefender]

How do you know the entrance to the slot is behind their radiator? If this is the case then the energy of the airflow will have been seriously reduced and the slot turns into a vent for hot air. I'm not saying this is impossible just that it is improbable.

[...]

How is that improbable? The primary purpose of all sidepods is to be a vent for hot air. To say that performing its primary function is improbable is a bit like saying a steak probably shouldn't be eaten. I mean, I guess they'd make good doorstops, but they're much better when devoured, yanno?

Don't get me wrong here; I like the lateral thinking, because it's fun to ponder possibilities, and lord knows I've tossed around a few gems over the years. But, I just can't imagine an F1 engineer voluntarily adding a component with a highly questionable value for the intended application and that would nevertheless contribute to the problem it's meant to solve no matter how well it functions. Drag is drag regardless of origin.

But, as a vent for hot air? Absolutely.

Bad things happen...

http://i.imgur.com/rWbxawF.jpg

...when teams don't....

http://i.imgur.com/ZLHzfcD.jpg

...get that right.

http://i.imgur.com/eap0yTk.jpg

(Luckily, it doesn't really matter if either one of us are right. If only engineers had such a luxury...)

This isn't lateral thinking. Leading edge slots have been used on F1 sidepods for years now. Why is this any different? The mp4-28 started last year started with it, the torro rosso team used it as shown by the pic, ferrari have used it in various iterations.

You are misunderstanding me. I never said the sidepod doesn't vent hot air, I said it doesn't vent hot air THROUGH THAT SLOT. Please do not put words in my mouth. The thing about turbulent air is that in many cases it causes more drag, by adding this slot you can actually decrease turbulence and hence drag.

Decreasing drag is probably not the primary purpose of the slot though. By keeping the airflow laminar with minimum turbulence it means that further back the car can do more with that airflow. If Williams allows the airflow to stall going around the sidepods then you have turbulent air interacting with the rear wheel, the brake ducts, the rear wing, the monkey seat and exhaust area, the diffuser and in Mclarens case the complicated rear suspension. By keeping the airflow smooth, these devices function much better at producing downforce. Why do you think teams are always changing features around the top of the sidepods? Simply because the front of the sidepods have a big effect on the flow structure to the rear of the car.

[bhall]

It seems you're really married to this idea, which is fine. I can understand that, and I celebrate your spirit. I'll leave you with this:

Every team that has ever experimented with a solution that could possibly be construed as a leading-edge slot has consistently moved away from that design and toward other concepts as they've developed their cars. So, if this is, in fact, a solution intended to prevent detachment of boundary layer flow over the sidepod, it's clearly not very useful when compared to other solutions. (Or those teams were just plain hapless. Objectively speaking, I have to concede that such a possibility can't be summarily dismissed.)

At any rate, I maintain they've all been vents that have appeared and disappeared as needed throughout the course of a car's internal aerodynamic development, because the ideal sidepod has only two apertures, and race teams tend to be in the business of chasing ideal solutions wherever practicable.

[LookBackTime]

Today pictures:

[JDC123]

Why is it that this year teams have really large DRS activators/hinges compared to some of the extremely small one last year. I can't see this being because of the reduction in rear wing depth.