modbaraban wrote:Just an idea. There's a rain button on the wheel that turns on the rear light. Perhaps it switches the rev-limiting electronics to rain mode too.
differnet engine maps, different TC maps, etc etc. that's a fairly well known fact.
Well, air + water is heavier than air alone, plus the air itself is thicker due to humidity. I mean, look at the huge rooster tails. Displacing that much water has to produce some amount of extra downforce, yes?
yes, F1 cars want more down force for driving in wet conditions. this is because the lower coefficient of friction on a wet track needs to be balanced by an increase of normal force (down force). when the track is wet, the teams will try to increase their down force with wing, aero bits and ride height adjustments. traction control, suspension softening, engine mapping and gearbox adjustments will also help improve grip . remember that in the wet; you won't be riding the curbs as much and your overall speed will be lower so you can have a lower ride height and softer springs.
with a given wing design and angle, down force will increase proportionally with air density. therefore in hot and dry conditions the wing produces slightly less down force than in cold and humid conditions. but not in the rain. water droplets from rain and spray attach to aero surfaces and totally disrupts the laminar flow desired by the wings. this destroys aero down force. water droplets also have friction and mass which sucks energy from the car. in the rain, the car is always trying to hydroplane; which means that its always climbing a hill to get on top of the water. also, the water sprayed up and atomized into mist, behind each car, took energy from the car to get it there. (80l/s X4 tires is a lot of water mass to move.
as seen in another thread, the teams design different Front Wings (FW) for each specific track (well, the rich teams do) because each track has specific needs. although some tracks share similarities, the teams are constantly developing so if there were 2 races at the same track over 2 consecutive weekends; the teams would further develop their wings. this being said, each fw has a certain degree of adjustment. this is usually used to balance the car. increasing the fw angle will increase front down force but it can only be dialed in based on the rear wing and other mechanical and aero adjustments. so.... yes, front wing adjustment will help grip in the wet but there are many other adjustments that have to be made to allow for more front wing because front wing adjustment is mostly used for balance.
AeroGT3 wrote:Rain makes for more downforce just from rain alone, let alone adjustments teams make.
So you are saying that when it is raining (and everything else being equal) a car will produce more downforce? I dont think so.
Other than gut feeling, why do you say that?
Air + water is a high density than pure air.
And the angle of incoming flow with air, compounded, is also downwards with rain added. If you look at it from a mass/momentum point of view, its a higher density fluid making a bigger change in the direction of its motion. Why would that amount to less downforce?
I know it´s movable aerodynamic device but what happens if you have ducting blowing highvelocity air in front of the tyres? Would it clean the water from the tyre´s way?
AeroGT3, even thouh the air density conditions are the same for everybody, my intuition would tell me that the change in air density may change the car's overall aerodynamic efficiency relative to another car's. Is this correct?
You can't mix them together.
Water is not in the air.
The air is surrounding the water trops, but they stay for them alone.
So spraying water in the air thosen't change the density of the air.
Here comes a thing who Inside Line posted:
that the water drops don't flow around the wing. They only attach to it.
It could be other with water steam.
But we don't talk about that now because it doesn't fit our natural conditions.
But air can take a little amount of watermoleküles.
Which is not steam.
I think in english it's called humidy.
The amount depends on the Temperature of the air.
The hotter the air, the more water can be taken.
So it's other than in Inside Lines post.
hot air - high humidy ca 3%
cold air - low humidy 0,1%
That's a reason why engines produce more power in cold conditions.
And in the wet you have to rise your ride high because the flat bottom of the car tends to swim over the water like a surfboard.
mep wrote:...The amount depends on the Temperature of the air.
The hotter the air, the more water can be taken.
So it's other than in Inside Lines post.
hot air - high humidy ca 3%
cold air - low humidy 0,1%
That's a reason why engines produce more power in cold conditions...
I dont think so.
1) Engines produce more power in cold conditions due to better volumetric efficiency due to cold air higher density
2) in any thermal machine, "rendimiento" (please someone translate this word correctly, I think its performance) depends from cold and hot sources temperatures (this derives from 2nd law of thermodynamics)
"You need great passion, because everything you do with great pleasure, you do well." -Juan Manuel Fangio
"I have no idols. I admire work, dedication and competence." -Ayrton Senna
they are both fluids for the purposes of physics and the movement of them. To take this to the extreme - if the cars drove through water would they generate more downforce? Of course they would.
It makes sense.
With regards to engines producing less power in the wet - I see no reson why this would be. Unless your airfilter becomes saturated as per the BMW in japan last weekend. The cooler the air the more charge per revolution and so the more fuel you can burn.
Has anyone seen water tunnels are sometimes used instead of wind tunnels as this allows one to obtain a higher Reynolds number for a given flow speed, due to the higher density of the fluid. This indicates the similarity of air, a gas, and water, a fluid, both being simulated as a fluid. In CFD air is modelled as a fluid rather than a gas.
In the rain downforce is usually increased as already stated to compensate for the reduced co-efficient of friction. Although the rain itself may increase the downforce slightly, the affect will be minimal in my view.
Tyres, I am still a little in the dark when it comes to pressures I have heard 3 trains of thought from proffesionals and club level,
1) Increase from dry pressures - Decrease contact patch size make it work harder to increase temperature (This was from an Indy car driver/team so not sure how true seems they don't even run in the wet!)
2) Reduce the pressures making the side walls distort and induce heat into the carcuss (I've heard this more often than any of the others from club levels - If it rains everyone but me reduces the're pressures as I work on the next train of thought)
3) Keep the pressures the same (I contacted Avon Tyres and they advised to make no changes from the optimum dry pressures as the carcuss is designed around these pressures)
Your thoughts and experiances would be interesting.
