7 replies to this topic

[Jackmancer]

With the KERS/ERS and energy recovery from the brakes, does anyone know how much energy is actually recovered during braking? Obviously it depends, but let's say an average turn one after the straight? 300 km/h to zero?

 

I'd love to know this. I work in the renewable energy business and they don't understand why I like F1 I want to blog about this, too.

 

 

[gruntguru]

MGUK limit is 120 kW and 300km/hr to 200km/hr takes about 0.7sec giving a harvest of 120 x 0.7/3600 = 0.023 kW.hr

 

200 to 100 takes about double that (less aero DF and drag) so perhaps another 0.05 kW.hr.

 

Below 100 km/hr braking power reduces  rapidly (power = force x velocity. Both force and velocity are significantly reduced). If you assume 1G braking on the rear wheels at lower speeds, 120 kW would only be available above about 60 km/hr (probably much higher in reality).

Edited by gruntguru, 18 August 2015 - 08:23.

[RogerGraham]

Out of all that, what stands out is "300km/hr to 200km/hr takes about 0.7sec".  

 

That's pretty incredible, and no wonder first-time F1 drivers always seem comment on the braking, not the acceleration.

[gruntguru]

0.7 seconds is conservative. Brembo claims 308 kph to 126 kph in 1.22 seconds at Montreal.

 

http://www.formula1....treal-05-07-jun

 

[Wuzak]

The stops listed on that Brembo page add up to 7.7s of stopping time.

 

http://www.formula1...._canada_eng.pdf

 

If they can use 120kW MGUK braking for that entire time it equates to 924kJ/0.256kWh - less than half the amount allowed under the regulations.

 

In contrast, Monaco has 14.05s of braking.

 

http://www.formula1...._monaco_eng.pdf

 

That equates to the 1686kJ, much closer to the 2000kJ of ecovery allowed.

[Wuzak]

Which illustrates one of the reasons why the drivers "lift and coast". That is, in order to actually get the allowed amount of recovery.

[GVera]

Which illustrates one of the reasons why the drivers "lift and coast". That is, in order to actually get the allowed amount of recovery.

 

Also illustrates how important it is to have a good MGUH.

Edited by GVera, 19 August 2015 - 19:12.

[mariner]

Those Brembo numbers are amazing. The car loses roughly 10 mph in 0.1 of a second and less than one metre.

 

The driver also pushes , it seems ,at about 2.2 times his bodyweight.

 

The wonders of aero plus  CF discs!

 

Mind you as the car is about 5 metres long so it needs , say , 10 metres advantage to pass under braking or a 10% extra braking effort inside the 1.22 secs.

Edited by mariner, 20 August 2015 - 10:19.