Coefficient of Friction for F1 Tyre

Here are our CFD links and discussions about aerodynamics, suspension, driver safety and tyres. Please stick to F1 on this forum.
Post Reply
al_garnett
0
Joined: 31 Oct 2014, 16:06

Coefficient of Friction for F1 Tyre

Post

I know this is a very complex subject which is almost impossible to provide a correct answer for but....

I'm looking for a value of the coefficient of friction for a Formula 1 tyre that can be used in the tyre friction force equation.

Any idea of a value that can be used would be great thanks

Greg Locock
230
Joined: 30 Jun 2012, 00:48

Re: Coefficient of Friction for F1 Tyre

Post

mu_typical=1.5

Tommy Cookers
616
Joined: 17 Feb 2012, 16:55

Re: Coefficient of Friction for F1 Tyre

Post

motorcycle cornering is aero-neutral
lean angles up to 64 deg are claimed (though presumably back-calculated from cornering data calculations)
some of the notional 64 deg toppling vector works against wheel gyroscopic reactions (continuous in steady-state conditions)
this 'some' was stated to be 2-4 deg (please feel free to calculate this, anyone)

the above implies a Mu value of 1.75 - 2

Greg Locock
230
Joined: 30 Jun 2012, 00:48

Re: Coefficient of Friction for F1 Tyre

Post

Bear in mind that mu is load sensitive, so an f1 tire at 4g vertical load, ie a high speed braking event, will have a lower mu than it would at more moderate speeds.

Personally I think using the low speed longitudinal acceleration is fraught with difficulties, I use corners.

dynatune
13
Joined: 28 Aug 2013, 11:03

Re: Coefficient of Friction for F1 Tyre

Post

Typically at 0° Camber an F1 tire provides in the range of 1 kN to 3 kN Vertical Load a Coefficient of Friction of around 1.6 which then drops down to around 1.4 around 6 kN vertical load.

Cheers,
dynatune, http://www.dynatune-xl.com

silente
6
Joined: 27 Nov 2010, 15:04
Contact:

Re: Coefficient of Friction for F1 Tyre

Post

i described on my blog a procedure you could use to reverse engineer a tire model basing on rough track data and vehicle information.

It could apply pretty well to this question...

https://drracing.wordpress.com/

User avatar
Tim.Wright
330
Joined: 13 Feb 2009, 06:29

Re: Coefficient of Friction for F1 Tyre

Post

Cheers Paul, interesting info.

There had been friction coefficients of 2 for an F1 tyre being pedaled about on the forums here relatively recently which I found hard to believe.

I proposed another method to extract the coefficient of friction of the complete car and the downforce coefficient in another thread:
1. For a given circuit (or better still a number of circuits with similar aero setups) make note of the velocity and lateral acceleration through each corner. You can take this from an onboard lap or from one of the track diagrams that the various teams put out.

2. Put all of these datapoints on a scatter plot with speed as the horizontal axes and lateral acceleration as the vertical axes.

3. Fit a squared polynomial to the data in the form: LatAcc = a.Speed^2 + b

4. Then you have:
Tyre friction coefficient: mu = b/9.81
Downforce: SCz = (2 x mass x a)/(mu x AirDensity)
Obviously, as Greg pointed out you should take the data from corner which are traction limited only.

Tim
Not the engineer at Force India

Blanchimont
214
Joined: 09 Nov 2012, 23:47

Re: Coefficient of Friction for F1 Tyre

Post

If i follow shooty81's method at the start of the race with downforce not considered as it is pretty much zero for the first few meters and

acceleration = 0,9G(1) and 1,1G(2)
mass(car+fuel) = 691kg + 95kg
wheelbase = 3,4m(1) and 3,5m(2)
COGh = 0,25m(2) and 0,3m(1)
wdr = weigth distribution rear = 54%(2) and 55%(1)
ft_corr = 1,01(1) and 1,03(2) (to account for the rotational energy of the front tyres and brake discs only, the rear axle is not accelerated by the rear tyre force)

accleration * mass * ft_corr = (mass * wdr *9,81N/kg + COGh/wheelbase * mass * acceleration) * friction_coeff

then (1) results in 1,444 and (2) gives 1,832 for the longitudinal friction coefficient.
Dear FIA, if you read this, please pm me for a redesign of the Technical Regulations to avoid finger nose shapes for 2016! :-)

Post Reply