F1technical.net

wesley123 wrote: ↑

07 Aug 2017, 12:03

Joseki wrote: ↑

07 Aug 2017, 11:28

It's the third consecutive year that they say it, maybe this time they'll do it.

They never said so before.
see

To be fair, Honda did say that they would be at Mercedes Abu Dhabi 2016 level at the beginning of the year.

What I find interesting is that they are targeting power levels higher than Merc 2016 since I thought that all they could get upto this year was Merc 2016. Also I think my estimate of 925 HP seems on target since they mention that this is the closest they have been to others since they started. (This if of course with all the caveats about what peak HP numbers really mean.)

FvtecA wrote: ↑

07 Aug 2017, 15:03

wesley123 wrote: ↑

07 Aug 2017, 12:03

Joseki wrote: ↑

07 Aug 2017, 11:28

It's the third consecutive year that they say it, maybe this time they'll do it.

They never said so before.
see

To be fair, Honda did say that they would be at Mercedes Abu Dhabi 2016 level at the beginning of the year.

What I find interesting is that they are targeting power levels higher than Merc 2016 since I thought that all they could get upto this year was Merc 2016. Also I think my estimate of 925 HP seems on target since they mention that this is the closest they have been to others since they started. (This if of course with all the caveats about what peak HP numbers really mean.)

They said it according to one cylinder data. It was true at single cylinder but not true at v6. So there is real data show them what they said. I don't think they do same mistake twice.

[quote=henry]
I don't know what the power requirement is. I took a stab in order to have number to illustrate the energy implications of deployment options. I gave a source for my stab
Are you saying that the same ICE power could be available over a range of air/ fuel ratios and that the choice of higher ratios, and hence higher MAP, is down to reducing the need for cooling? And the consequence of lower MAP would be reduced compressor power and would lead to higher MGU-H power and so longer MGU-K deployment?[/quote]

in the race very high AFR (and MAP) so dilute the fuel heat that energy necessarily taken from the cylinder and dumped via coolant is unusually small
so more in-cylinder energy is present to be expanded into work ie there's more power eg at 100 kg/hr fuel rate
this is fine due to the turbocharging
gruntguru's figures iirc have always shown big powers going into compressing and to the turbine at high MAPs
so the recovery hardly improves with AFR/MAP

with electric supercharging/wastegating for qually every available bit of K motoring energy is very laptime-valuable due to the ERS 4 MJ lap limit
reduced AFR/MAP saves electrical energy disproportionately (from reduced compressor work and increased ? blowdown turbine work to compressor)
with reduced AFR/MAP the fall in ICE power from reduced 'forward pressure' is c. 2% - but total PU work output/lap (and especially laptime) is better
and of course exceeding one lap duration requires increased cooling and so significantly reduces ICE power

I think this current exchange is illustrative of the problem with the V6 Hybrid Era. We have a few people in this discussion who are extremely knowledgeable about engines, material science, or general math yet even with these above-average folks we can't get the full picture of how combustion or energy fill and deployment work in these power units. Part of me feels F1 engines must be complex because they're state-of-the-art; however, these things are a bit over the top. An alternative would be for FOM to embrace the tech. and share more details so curious people can geek out on it.

They should require that every manufacturer has to publish their design after 12 months.

ZakB wrote: ↑

07 Aug 2017, 20:12

They should require that every manufacturer has to publish their design after 12 months.

It would be fantastic for not only the sport but also for the car industry as a whole if they did that - but I don't see it happening any time soon!
Some of the things solved a long time ago in F1 continue to be a problem in other areas.

That would be a LOT of stuff to digest.

They're contemplating how to get rid of a lot of the secrecy in F1 and I think with current complexity that's a must.

So many things are unknown; would be great just to know how much Honda is lacking and in which department. Would be superb for us to get access to all data (incl gps analysis).

Explain the strategies, the mappings and the setup choices. Now it's all one big box and because it's less transparent with the hybrids you often don't understand why a driver is pacing himself for instance.

henry wrote: ↑

07 Aug 2017, 21:58

That would be a LOT of stuff to digest.

Well, it would be amazing to see what they can do with all the information of others, although this will probably never happen, sadly enough.

Tommy Cookers wrote: ↑

07 Aug 2017, 10:48

don't we need far more than 40 kW to drive the compressor (eg electrically) for 4 bar MAP ? even with the trickle of blowdown power making a mechanical contribution to said driving but a small reduction in MAP will give a big reduction in the compressor power required and the blowdown power's contribution will significantly increase if the cooling rate is not increased and there's no internal distress in this brief excursion from race condition the ICE power won't fall so the PU power and the amount of K motoring will be maximised

Compressor power at PR=4 is about 100 kW.

I believe they would run the highest MAP possible during "balls out" operation. Running an extra 1 bar MAP will cost some electrical energy, but the ICE output will increase by approximately 1 bar BMEP (pumping gain with zero exhaust back pressure) so a decent chunk of that electrical energy gets to the rear wheels. This is a de-facto method for getting ES energy to back wheels to get around the MGUK limits of 120 kW and 2 MJ/lap.

Interesting note. This "air-motor" technique loses efficiency as intercooling is increased.

Edited to acknowledge TC's allowance of 2% ICE power gain from "forward pressure" - sounds about right for 1 bar MAP increase. I don't think electrical energy is all that precious in a qualy lap - the potential for "hot blown" MGUH harvesting is quite large and they can only use 2 MJ/lap in the K.

The air motor technique has a draw back too. To compress that higher pressure air is also more difficult. Best illustrated when you remove the spark plugs to turn the engine easier. Some caculation would have to be done to see the net power transfer by doing this.

PlatinumZealot wrote: ↑

08 Aug 2017, 03:54

The air motor technique has a draw back too. To compress that higher pressure air is also more difficult. Best illustrated when you remove the spark plugs to turn the engine easier. Some caculation would have to be done to see the net power transfer by doing this.

Most of the compression work in a piston engine is returned on the power stroke. If the engine is motored (rotating but un-fired) most of the compression work is returned on the expansion stroke (the un-fired "power" stroke).

gruntguru wrote: ↑

08 Aug 2017, 01:15

Tommy Cookers wrote: ↑

07 Aug 2017, 10:48

don't we need far more than 40 kW to drive the compressor (eg electrically) for 4 bar MAP ? even with the trickle of blowdown power making a mechanical contribution to said driving but a small reduction in MAP will give a big reduction in the compressor power required and the blowdown power's contribution will significantly increase if the cooling rate is not increased and there's no internal distress in this brief excursion from race condition the ICE power won't fall so the PU power and the amount of K motoring will be maximised

Compressor power at PR=4 is about 100 kW.

I believe they would run the highest MAP possible during "balls out" operation. Running an extra 1 bar MAP will cost some electrical energy, but the ICE output will increase by approximately 1 bar BMEP (pumping gain with zero exhaust back pressure) so a decent chunk of that electrical energy gets to the rear wheels. This is a de-facto method for getting ES energy to back wheels to get around the MGUK limits of 120 kW and 2 MJ/lap.

Interesting note. This "air-motor" technique loses efficiency as intercooling is increased.

Edited to acknowledge TC's allowance of 2% ICE power gain from "forward pressure" - sounds about right for 1 bar MAP increase. I don't think electrical energy is all that precious in a qualy lap - the potential for "hot blown" MGUH harvesting is quite large and they can only use 2 MJ/lap in the K.

In wastegate mode the compressor is driven by a combination of blowdown energy from the turbine and electrical energy from the ES. So 100 kw is mitigated by blowdown power level. TC suggests this is a trickle. We know blowdown plays a part because of the positioning of the wastegates.

The permissable energy to MGU-K is 4 mJ per lap.

How precious the electrical energy is will, I think, depend on the lap. On long high speed laps, where they might run out, they will want to deploy that energy at as low speeds as possible to maximise acceleration and minimise lap time.

With higher MEPs in such a mode, wouldn't you run into lean combustion issues since the flow rate is limited? I figure the PU as a whole would be designed around best performance/efficiencies at 'normal' operating conditions.

As the combustion aims to become more diesel like (in terms or air fuel ratios not the ignition i am speaking of here) more air is not a bad thing. As long as temps are controlled. I actually think FIA should increase the displacement size to two litres to enable even leaner burn using slightly lower pressure ratios.