Jump to content


Photo
* * * * * 3 votes

MGU-K Energy recovery


  • Please log in to reply
78 replies to this topic

#51 grunge

grunge
  • Member

  • 4,305 posts
  • Joined: May 09

Posted 10 February 2014 - 14:58

Not in the pit of course.

Out-lap would probably be enough but I think they need to push it a little bit more compare to last year.

One more important factor in qualifying this year, it is unlikely for drivers to do 2 consecutive max power lap, so you will need a recharge lap into between two max power lap.

Thats a very interesting point..ud want to use a fully charged ES for a hot lap...so it could very well go like this

Out of the pits>outlap(fully charge ES)>hot lap>slow lap(charge ES again)>another hot lap.

This is ofcourse pertaining the super soft pirellis next year are tough enough to handle 4 laps without getting worn out..

Edited by grunge, 10 February 2014 - 14:59.


Advertisement

#52 dau

dau
  • Member

  • 4,569 posts
  • Joined: March 09

Posted 10 February 2014 - 15:55

The rule states you can't increase the amount of stored energy in ES in the pitlane. Whether you directly charge the battery or running MGU-K in the pitlane, you are in fact increasing the charge which is specifically prohibited.

That concerned race pit stops only, they were allowed to charge the battery in the pits for qualifying as far as i'm aware. 

 

5.2.4 The amount of stored energy in any KERS may not be increased whilst the car is stationary during a race pit stop. 
 
That's from last year's regs, i can't even find anything like that in the 2014 Technical Regulation atm.


#53 toofast

toofast
  • Member

  • 463 posts
  • Joined: October 12

Posted 10 February 2014 - 17:15

 

That concerned race pit stops only, they were allowed to charge the battery in the pits for qualifying as far as i'm aware. 

 

5.2.4 The amount of stored energy in any KERS may not be increased whilst the car is stationary during a race pit stop. 
 
That's from last year's regs, i can't even find anything like that in the 2014 Technical Regulation atm.

 

 

I got that from the energy flow appendix. I don't know if it has changed.

 

zx5xf4.png


Edited by toofast, 10 February 2014 - 17:21.


#54 dau

dau
  • Member

  • 4,569 posts
  • Joined: March 09

Posted 10 February 2014 - 17:44

Ah, ok, that settles that. Why write it as another article when you can easily hide it in a graphic where Ctrl-F doesn't work.



#55 Wuzak

Wuzak
  • Member

  • 3,489 posts
  • Joined: September 00

Posted 10 February 2014 - 20:13

Put the gearbox in neutral and run the pragram. At 120kW it would take 16.7s (2MJ) and 33.3s (4MJ) to charge.
 
Or you could get that on the out-lap.

 
 

I think I'm with I2K2 in this one, you not only need the rpm, you need the "load" on the engine as well.
To be able to harvest the extra app. 110 hp (82 kW) from the MGU-H you not only need 11k rpm, you need your engine to make 600 hp at 11k rpm.
In neutral, with no load, you will have 11 rpm but your engine doesn't produce the power.
How much throttle do you need, to rev your roadcar (or bike) to the limiter (in neural)?
 
What you could do, but I don't think, that's the way they will do it, is to jack the car up, and drive it against the brakes, the same think you do, in a "normal" turbo car, if you want to built up the boost pressure. Rally cars at the start of an stage for example, used to do this - hard on your clutch as well, if the car is at standstill. (like a airplane, applying trust but still having the brakes on, before takeoff)
 
Which brings us to another question, and this was already bandied around last year, what do the rules say about "left foot braking", meaning in this context, what if you have an overlay between throttle and brake input? Are you allowed to harvest from the MGU-K under this condition?
If so, you could use this technique to charge the ES at the maximum possible rate.
It will cost a load of fuel, but in Qualifying this shouldn't matter.
The question is, do the rules allow this?


TC, I agree with you regarding MGU-H generation while stationary in the pits.

The post above was about using the MGU-K to charge the batteries. This would load the engine up to 120kW.

#56 Wuzak

Wuzak
  • Member

  • 3,489 posts
  • Joined: September 00

Posted 10 February 2014 - 20:17

3.@wuzak....kudos on an excellent analysis..although as someone pointed put brake bias is altered many times during a single lap,and then many times during different phases of the race..very difficult/impossible to use a fixed value in calculations


Thanks.

As wrcva noted, the calculations I did are very basic to give an indication on the amount of recovery available to teams this year.

However, since the rear wheels will, regardless of brake bias settings, require >120kW of braking effort in most braking zones, the MGU-K should still manage that amount. The electronic braking will just switch the effort between the MGU-K and the brakes, depending on load and the bias settings.

#57 Coops3

Coops3
  • Member

  • 1,582 posts
  • Joined: March 11

Posted 11 February 2014 - 13:24

The OP had me feeling stupid with all the abbreviations and technical talk I didn't understand, so I decided it was time to read up on it. This is quite a good article if anyone's in a similar position:

 

http://www.pitpass.c...-Energy-F1-2014



#58 wrcva

wrcva
  • Member

  • 1,008 posts
  • Joined: January 10

Posted 12 February 2014 - 22:11

McLaren mgu-k close up pictures and specs (link)



#59 TC3000

TC3000
  • Member

  • 1,021 posts
  • Joined: September 09

Posted 16 February 2014 - 23:01

perhaps worth a read for the technical minded fan.

 

http://www.worldacad...no02paper08.pdf



Advertisement

#60 ollebompa

ollebompa
  • Member

  • 622 posts
  • Joined: November 13

Posted 17 February 2014 - 10:34

If i understand right we could be looking at 860- 920 max HP in qualifying. 600- 650 from ICE, 100- 110 direct from H to K all wich is continious power .Plus 4MJ from ES at the maximum rate of 120Kw(161HP) :)

#61 RoutariEnjinu

RoutariEnjinu
  • Member

  • 2,344 posts
  • Joined: March 09

Posted 17 February 2014 - 10:50

I wonder if someone close to the edge of the fuel limit might settle for a position for the remaining laps, and sit behind a slower (maybe lapped) car and use full DRS on every single lap but without ever overtaking? I wonder how much fuel could be saved down the straight while still going reasonably quick?

#62 oetzi

oetzi
  • Member

  • 2,982 posts
  • Joined: April 10

Posted 17 February 2014 - 12:06

If you can save a lot of fuel that way, might we see races where everyone is fighting to be second so they can save as much fuel as possible with the intention of blasting past the leader late in the race? But the leader is going as slowly as possible to back them up before making a break for it? A bit like very expensive pursuit cycling? Or maybe more like stage cycling, with people breaking from the peloton and hoping they have judged it right? Even groups breaking and taking turns to lead to collectively preserve fuel while building a gap?

 

:drunk:



#63 Neophiliac

Neophiliac
  • Member

  • 279 posts
  • Joined: March 09

Posted 17 February 2014 - 12:16

If you can save a lot of fuel that way, might we see races where everyone is fighting to be second so they can save as much fuel as possible with the intention of blasting past the leader late in the race? But the leader is going as slowly as possible to back them up before making a break for it? A bit like very expensive pursuit cycling? Or maybe more like stage cycling, with people breaking from the peloton and hoping they have judged it right? Even groups breaking and taking turns to lead to collectively preserve fuel while building a gap?
 
:drunk:


The only issue being of course that it's much harder to overtake in F1 than in cycling even with all of the overtaking aids, so that sort of strategy could backfire quite spectacularly.

#64 RoutariEnjinu

RoutariEnjinu
  • Member

  • 2,344 posts
  • Joined: March 09

Posted 17 February 2014 - 12:22

The only issue being of course that it's much harder to overtake in F1 than in cycling even with all of the overtaking aids, so that sort of strategy could backfire quite spectacularly.



I was thinking of the flat out tracks with lots of straights where the 100kg fuel limit will be very tight and require fuel saving at some point.

It's obviously not going to help at the tight slow tracks, but at ones with lots of full throttle action, could it pay off to stay in second and draft down every straight, but lifting enough on the throttle so as not to overtake.

Towards the end of the race you might have saved enough to be able to go full throttle for the remaining laps while the guy ahead of you still has to fuel save.

#65 oetzi

oetzi
  • Member

  • 2,982 posts
  • Joined: April 10

Posted 17 February 2014 - 12:23

 

The only issue being of course that it's much harder to overtake in F1 than in cycling even with all of the overtaking aids, so that sort of strategy could backfire quite spectacularly.

 

It wouldn't be too hard if you could run the last 30 laps at 100% and the car in front could only go at 80%. It's the ones behind you you'd have to be worried about.


Edited by oetzi, 17 February 2014 - 12:24.


#66 oetzi

oetzi
  • Member

  • 2,982 posts
  • Joined: April 10

Posted 17 February 2014 - 12:27

I was thinking of the flat out tracks with lots of straights where the 100kg fuel limit will be very tight and require fuel saving at some point.

It's obviously not going to help at the tight slow tracks, but at ones with lots of full throttle action, could it pay off to stay in second and draft down every straight, but lifting enough on the throttle so as not to overtake.

Towards the end of the race you might have saved enough to be able to go full throttle for the remaining laps while the guy ahead of you still has to fuel save.

With the massive amount of drag these cars generate, even the slower tracks would have some potential for fuel saving by slipstreaming. I wonder if the 'retardation warning lights' were partly introduced with this possibility in mind?



#67 balmybaldwin

balmybaldwin
  • Member

  • 137 posts
  • Joined: January 14

Posted 17 February 2014 - 12:41

If i understand right we could be looking at 860- 920 max HP in qualifying. 600- 650 from ICE, 100- 110 direct from H to K all wich is continious power .Plus 4MJ from ES at the maximum rate of 120Kw(161HP) :)

 

I think you've misunderstood a little.  Max power will be ICE + 160bhp from MGH-K as this is the max output from the K unit.  The confusion comes from the fact that you can run the K unit on power either from the MGU-H unit directly (up to about 100-120BHP) of from the energy Store (up to 160bhp) or a mixture of both (120 from the H and 4o from the ES).  The amount of energy from the ES is limited to 4MJ (for both driving the K unit or for spooling up the turbo), but there is no limit to the amount of energy that can go direct from the H unit to the K unit.

 

Therefore if ICE numbers predicted are correct (I think most are saying approx 650bhp) then we should be looking at 810 max power (which isn't too shabby especially as the power band is much wider with the new power units)



#68 ollebompa

ollebompa
  • Member

  • 622 posts
  • Joined: November 13

Posted 17 February 2014 - 13:12

I think you've misunderstood a little. Max power will be ICE + 160bhp from MGH-K as this is the max output from the K unit. The confusion comes from the fact that you can run the K unit on power either from the MGU-H unit directly (up to about 100-120BHP) of from the energy Store (up to 160bhp) or a mixture of both (120 from the H and 4o from the ES). The amount of energy from the ES is limited to 4MJ (for both driving the K unit or for spooling up the turbo), but there is no limit to the amount of energy that can go direct from the H unit to the K unit.

Therefore if ICE numbers predicted are correct (I think most are saying approx 650bhp) then we should be looking at 810 max power (which isn't too shabby especially as the power band is much wider with the new power units)

So the amount power from MGU-K is limited by regulations at 120KW? I had missed that.Back to reading the regs for me:) Thanks!

#69 Jeeves

Jeeves
  • Member

  • 59 posts
  • Joined: November 11

Posted 17 February 2014 - 15:15


Let's run a quick and dirty example with a generic F1 car. mass = 750 kg , height of CoG = 0.25m, wheelbase = 3.3 m, average deceleration = 3g

Our base car uses the 46/54% weight distribution, which means that it is carrying 345kg on the front and 405kg at the rear axle.

How is this looking when braking with 3g?

750*3*0.25/3.3 = 170 kg ( I will show it in mass units kg, to make it easier to follow, you can do the conversions to N if you like)

This means me have a load transfer of 170 kg @ 3g, our rear is getting 170 kg "lighter" while our front is getting "heavier".

 

front: 345kg + 170kg = 515kg  515/750 = 68.7 %

rear:  405kg - 170kg = 235kg   235/750 = 31.3 %

 

I believe you need to include downforce to this calculation. If an F1 car is decelerating at the rate of 3 G's, the axial loads will be quite a bit more than just the static weight & load transfer effect combined.



#70 TC3000

TC3000
  • Member

  • 1,021 posts
  • Joined: September 09

Posted 17 February 2014 - 16:23

I believe you need to include downforce to this calculation. If an F1 car is decelerating at the rate of 3 G's, the axial loads will be quite a bit more than just the static weight & load transfer effect combined.

 

Yes, agreed - you then would also need to account for the shift in CoP, and it's effects

 

Nevertheless, as for the context of the discussion, the following illustrations shows, a brake force of 7414 N [per wheel] at the front vs. 3112 N [per wheel] at the rear, for 4.4 g total deceleration.

In other words app. 70% at the front vs. 30% at the rear. 

 

M4UVW2B.jpg



#71 Neophiliac

Neophiliac
  • Member

  • 279 posts
  • Joined: March 09

Posted 17 February 2014 - 20:05

I was thinking of the flat out tracks with lots of straights where the 100kg fuel limit will be very tight and require fuel saving at some point.It's obviously not going to help at the tight slow tracks, but at ones with lots of full throttle action, could it pay off to stay in second and draft down every straight, but lifting enough on the throttle so as not to overtake.Towards the end of the race you might have saved enough to be able to go full throttle for the remaining laps while the guy ahead of you still has to fuel save.


In cycling you know with certainty that when you are drafting you will have an energy advantage relative to the guy in front. In F1, an active pursuit of this strategy will require an assumption that the guy in front is running at 100% while you are cruising behind and that he will in fact need to save fuel at some point. But in fact, how do you know? Maybe he has a second or two in his pocket and is cruising precisely to avoid any fuel isssues at the end of the race? Who knows. It's a bit like with tyres this year - you might think the guy in front of you is pushing and will run out of tyres on lap x, but then he just goes and goes and the drop off never comes when you expected it.

But my mind is very open. It may well be that someone will try and succeed in pulling off this maneuver - as you and oetzi say, fuel savings could well be quite considerable given the drag penalty. I very much look forward to finding out. And unlike the tyre situation, which was a bit of a lottery for each team where they had no idea when they would run into issues on their own car, let alone a car of the competitor, each team will know precisely its own fuel situation and will need to make calculated choices. That should make things quite interesting.

#72 Tenmantaylor

Tenmantaylor
  • Member

  • 8,316 posts
  • Joined: July 01

Posted 17 February 2014 - 23:11

As usual, the first half of the season will be more open and interesting than the second half in terms of unpredictably.

#73 oetzi

oetzi
  • Member

  • 2,982 posts
  • Joined: April 10

Posted 17 February 2014 - 23:35

In cycling you know with certainty that when you are drafting you will have an energy advantage relative to the guy in front. In F1, an active pursuit of this strategy will require an assumption that the guy in front is running at 100% while you are cruising behind and that he will in fact need to save fuel at some point. But in fact, how do you know? Maybe he has a second or two in his pocket and is cruising precisely to avoid any fuel isssues at the end of the race? Who knows. It's a bit like with tyres this year - you might think the guy in front of you is pushing and will run out of tyres on lap x, but then he just goes and goes and the drop off never comes when you expected it.

But my mind is very open. It may well be that someone will try and succeed in pulling off this maneuver - as you and oetzi say, fuel savings could well be quite considerable given the drag penalty. I very much look forward to finding out. And unlike the tyre situation, which was a bit of a lottery for each team where they had no idea when they would run into issues on their own car, let alone a car of the competitor, each team will know precisely its own fuel situation and will need to make calculated choices. That should make things quite interesting.

In F1 drafting works just the same as in cycling - whatever percentage effort the car in front is putting in, you're saving energy. So, if you're both fuelled somewhere close to the limit, you will get an advantage from doing it. Agree that the tyres situation is different, they kind of hung on then just let go, and nobody really knew when it would happen.

 

That could be a factor again this year, and if it is then you might well lose more in tyre life from staying close to the car in front than you could save in fuel. But that's one for once we've worked out what the fuel strategies are and which comedy foodstuff the tyres are made of this year (my money's on muffin).



#74 Jeeves

Jeeves
  • Member

  • 59 posts
  • Joined: November 11

Posted 18 February 2014 - 00:21

Yes, agreed - you then would also need to account for the shift in CoP, and it's effects

 

Nevertheless, as for the context of the discussion, the following illustrations shows, a brake force of 7414 N [per wheel] at the front vs. 3112 N [per wheel] at the rear, for 4.4 g total deceleration.

In other words app. 70% at the front vs. 30% at the rear. 

 

 

 

Why would one need to take the shift in CoP into account? It's a simple example with no suspension and the aero CoP set the same as the weight distribution, as you suggested in your earlier post.

 

If we imagine that the car would average 6000N of downforce during this braking example, we can situate it based on that fixed CoP. So instead of:

 

front: 345kg + 170kg = 515kg  515/750 = 68.7 %

rear:  405kg - 170kg = 235kg   235/750 = 31.3 %

 

We get:

 

front: 3385N + 1668N + 0.46 * 6000N = 7813N    =>  7813N / (7813N + 5545N) = 58.5%

rear:  3973N - 1668N + 0.54 * 6000N = 5545N    =>   5545N / (7813N + 5545N) = 41.5%

 

 

According to the illustration you linked, the front tires appear to have a friction coefficient of at least ~1.57. This would suggest that there's at least another ~4500N of unused braking force available for each rear wheel - which is likely to be a very cautious estimate, considering the fact that the rear tires are wider.



#75 TC3000

TC3000
  • Member

  • 1,021 posts
  • Joined: September 09

Posted 19 February 2014 - 19:56

Why would one need to take the shift in CoP into account? 

 

Do get a more realistic representation of what is happening in reality perhaps?

 

You made a good and valid point, by pointing out that my shown calculation is based on an too simplified model.

To get 3g deceleration, one would need to take aerodynamic downforce into account - I fully agree with this and you are right.

You propose another model, with added downforce, and this model shows, that the effect of the load transfer is diminishing, because it becomes less significant when considering higher vertical loads. There is nothing wrong with this either, but this model is based on the assumption that the downforce distribution remains static (CoP doesn't move) during braking.

 

And I'm not convinced, that this assumption is correct/applies in practice - that's all, an the reason I mentioned that one would then also need to account for the CoP movement and the effects it causes. Otherwise we replace on oversimplified model (my initial), with another oversimplified model (your model assuming a static CoP). 

 

It's not an F1 car, but I would expect a similar behavior in principle (as in CoP shifts under braking/pitch), which should help to show, what I wanted to point out, that CoP tends to shift forward under braking in most cars. 

 

pitch_01.jpg

 

or in absolute values, for an more F1 like vehicle model.

Front downforce tends to increase with a reduction in front right height, which will cause a shift in vertical wheel loads, balance and CoP.

 

rake.jpg



#76 Jeeves

Jeeves
  • Member

  • 59 posts
  • Joined: November 11

Posted 19 February 2014 - 22:32

Do get a more realistic representation of what is happening in reality perhaps?

 

You made a good and valid point, by pointing out that my shown calculation is based on an too simplified model.

To get 3g deceleration, one would need to take aerodynamic downforce into account - I fully agree with this and you are right.

You propose another model, with added downforce, and this model shows, that the effect of the load transfer is diminishing, because it becomes less significant when considering higher vertical loads. There is nothing wrong with this either, but this model is based on the assumption that the downforce distribution remains static (CoP doesn't move) during braking.

 

And I'm not convinced, that this assumption is correct/applies in practice - that's all, an the reason I mentioned that one would then also need to account for the CoP movement and the effects it causes. Otherwise we replace on oversimplified model (my initial), with another oversimplified model (your model assuming a static CoP). 

 

It's not an F1 car, but I would expect a similar behavior in principle (as in CoP shifts under braking/pitch), which should help to show, what I wanted to point out, that CoP tends to shift forward under braking in most cars. 

 

 

or in absolute values, for an more F1 like vehicle model.

Front downforce tends to increase with a reduction in front right height, which will cause a shift in vertical wheel loads, balance and CoP.

 

 

Yes, it does provide a more realistic representation, but only if you include suspension and tire deflection to the model as well. That's what I was referring to with the comment about no suspension. Though to be honest, I didn't expect the CoP shift to be of the sort of magnitude your 'vs. pitch angle'- graph indicates. What car is that by the way? A 20% portion of the total downforce to the front would seem like a pretty understeery setup for an openwheeler.

 

But even with such a wildly pitch-sensitive car, the tire load distribution between front and rear would only touch the 70-30 case momentarily - and to my understanding the brake bias only really comes into full effect when the driver is able to apply enough brake pressure to lock the wheels of the car. With this in mind I'm not exactly convinced of the 70-30 bias you're suggesting, but I suppose that will remain undecided unless someone who really knows can provide us with an answer.



#77 wrcva

wrcva
  • Member

  • 1,008 posts
  • Joined: January 10

Posted 11 May 2014 - 22:48

Ted on Ferrari (#14) MGU-K outputting > 120kw during Spanish GP quali  

 

  

 



#78 Ferrari_F1_fan_2001

Ferrari_F1_fan_2001
  • Member

  • 3,024 posts
  • Joined: May 01

Posted 11 May 2014 - 23:30

What do all these damn accronyms mean? Honestly....2014 F1 is like learning algebra or a new language


MGUK...MGUH....PU etc etc

#79 AngelaTifosi

AngelaTifosi
  • Member

  • 484 posts
  • Joined: March 14

Posted 12 May 2014 - 03:55

Ted on Ferrari (#14) MGU-K outputting > 120kw during Spanish GP quali  

 

  

 

:down:  :down:  :down:  :down:  :down:  :down:  :down: