Zynerji wrote: ↑
Wed Sep 15, 2021 5:29 pm
Dr. Acula wrote: ↑
Wed Sep 15, 2021 7:57 am
Zynerji wrote: ↑
Wed Sep 15, 2021 2:39 am
I'd argue the MGUH is THE single most roadcar relevant part of Formula 1.
Actually it's the probably the least roadcar relevant part. What do you need to make the MGU-H work well? Full throttle conditions. What do you hardly use in a road car, especially in city driving? Full throttle.
What can make sense in a roadcar is an electrical supported turbocharger. But you will never get into the situation where you can win substantial amounts of energy out of the Turbocharger in a roadcar like it is done in F1.
FW17 wrote:Is it possible for you to quantify this with MJ loss per lap and the weight of fuel required to compensate it?
The MGUK is 120kw assuming it runs 70% of the lap on full recovery(a big assumption) it will generate 1.9kwh which is 6.72 MJ
This is equal to 20kg fuel through the race.
If we consider only 4 MJ recovery a lap (about 50%), the saving is 12kg a race.
12kg is not much considering the MGUH along with its associated components probably weighs more than that
Years ago Magnetti Marelli had published a slide which showed the energy recovered per lap from the 2 different systems. Depending on the track the MGU-H could recover from about 4 to almost up to 8MJ per lap, i think it was in 2016. Also don't forget that you don't get all the energy out from the fuel to the road. The ERS system is at least twice as efficient compared with simply burning fuel, which means you save at least twice the amount you stated.
I'd say you need RPMs for the mguh more than full throttle. And that is custom made for downsizing.
What you really need is mass air flow, whether that comes from large throttle openings or huge RPM is largely irrelevant, but the more mass airflow, the more energy available to put into the turbo charger.
The reason MGU-H works on an F1 engine is they are limited to 125k RPM, which in comparison to modern road vehicle engines is slow, so when the turbo on the F1 engine approaches the speed limit, they just suck a load of electrical energy out of the MGU-H to keep a lid on turbo speed.
Two things you don't have, or indeed want to a certain extent, in a road application is massive throttle openings or RPM to promote huge mass air flow. But, the bigger problem for road relevance goes back to the point somebody was asking about earlier which is the cost of the MGU-H, the person asking is correct, a 125k RPM 3 phase electrical machine is not that expensive anymore. Neither is a motorsport turbocharger. Combining them both together is the issue. Motorsport engines produce a lot of heat and vibration. Exactly the two things that highly sensitive electrical machines do not like... trying to make a 125k RPM electrical machine that can cope with ~800 deg C and massive vibration is the big problem.
The MGU-H is essentially a basic form of waste heat recovery, it is recovery the energy left in the exhaust stream. There have been many studies over the years on waste heat recovery in vehicles and mobile applications, and it always falls down on the same problem, the cost of the system always outweighs the full it saves. Typically they are in the 2-6% territory on SFC saving, simple systems like MGU-H being at the bottom end of that range and full waste heat recovery systems with exhaust boilers, etc nearer the top.