Honda Power Unit Hardware & Software

[Bandit1216]

http://www.highspeedgenerator.com

[PlatinumZealot]

[quote="saviour stivala" post_id=892540 time=1583469854 user_id=39033]

Why if I may ask an MGU-H will need to change direction (I am assuming you mean direction of rotation) when ‘changing’ from motor mode to harvesting mode?.
[/quote]

torque direction of course! Not rotation direction. Haha. The things we write at night...

[Bandit1216]

One more thing; high rpm is the key to design high power to weight ratio electric motor/generator. Otherwise the mgu-h would be very big and heavy. So one wants the turbo as low rpm as possible, but the mgu-h as high rpm as possible. Kinda countering myself here

[PlatinumZealot]

The FIA seem to think it's feasible and allowable, and I am not willing to write any idea off that provides a gain, not sure why you are so vehemently opposed to the possibility which is all i'm suggesting[/color]

OK. The key here is that the FIA rules were designed from what was in the turbine industry at that time. You have small turbine starters that use a small retractable clutch to to start the turbine with a high speed motor from the compressor side. The clutch would retract once the turbine comes up to speed. This sort of layout fits well with the close couple turbocharger but obviously they were not envisioning the split design of Mercedes. It's not like they developed a technical design to know that that design would not be the optimum. I would say they were just giving allowance for different designs.

[PlatinumZealot]

One more thing; high rpm is the key to design high power to weight ratio electric motor/generator. Otherwise the mgu-h would be very big and heavy. So one wants the turbo as low rpm as possible, but the mgu-h as high rpm as possible. Kinda countering myself here

This is a good point.. because the speed could actually converge.

[Hkbruin2]

Honda at the track during preseason testing.

[NL_Fer]

A sprag clutch or one-way bearing between the turbine and mgu-h/compressor? Maybe there is a minimal decrease in compressor spinup time, at the moments when they hit the throttle.

Verstappen often complains about lag. A clutch could shorten turbo pressure buildup time.

[PlatinumZealot]

I'm going with the Garrett design. No clutch. Less parts. more efficient. Bonus! It actually exists!

[saviour stivala]

2014-15-16-17-18-19-20:- “The MGU-H must be solely mechanically linked to the pressure charging system. This mechanical link must be of fixed speed ratio to the exhaust turbine and may be clutched".
"The rotational speed of the MGU-H may not exceed 125000 RPM".
As at present:- “The weight of the MGU-H (as defined in line appendix 2 to these regulations) may not be less than 4kg”.

[KAIZEN]

But there are complications. Each of the four engines has an official turbine ‘burst point’ – the maximum speed at which it is safe and at which a failure would not result in the bursting of the turbo casing and the spreading of high-velocity debris all over the track. This burst point speed of each engine design is verified and homologated and provided to the FIA. The turbos cannot be run beyond this speed, regardless of the regulated limit of 120,000rpm. That simply means if the burst speed could be made as high as 120,000rpm, they would be allowed to run at that. But the burst speed is usually below that limit.
https://www.formula1.com/en/latest/arti ... VjIoq.html

[Bandit1216]

Underneath the specs of the only motor this company I linked has, that could be up to the job, assuming 80 kW. 7,5 Nm @100 000 rpm. I think the mgu-h must be something like this. I wonder what the elec specs are. The highest voltage IGBT, fast enough, are 1200V, which would still mean they have 66A. (Quick google). About 1liter steel/copper, so would be more than 4kg.


Type Synchronous
Number of poles 4
Winding protection Standard
Stator cooling Water
Rotor material Permanent magnet
Stator OD 120.00 mm
Stator Stack Length 100.00 mm
Total length max 184.00 mm
Rotor ID max 31.00 mm
Rotation speed max 114'000 min-1

[saviour stivala]

“The turbo burst-point speed design is verified and homologated, and provided to the FIA. The turbos cannot be run beyond this speed” Common sense that the turbos cannot be run beyond their individual safe running maximum speed, irrespective if that safe maximum running speed is homologated or not. But a question: “Regardless of the regulated limit of 120000rpm (the author was talking of 120000rpm regulated turbo speed)”. Where in the regulations since the start (2014) of the new 1.6l turbocharged engine formula is it stated that the turbocharger is regulated at a maximum of 120000rpm?.

[Espresso]

[quote=PlatinumZealot post_id=892536 time=1583466367 user_id=6109]
Oh transparent one, why do you suppose the turbchargers are spinning close to 120k rpms?

When the formula began in 2014 guys like Ferrari and Renault had very small turbochargers. They realised they predictions were totally wrong and they were in a total different mode of operation to what Mercedes were doing so they had to increase the size drastically the following year.

They were smaller and lets say maxed out at 125k,(i doubt it) thhen imagine bigger, more efficient turbochargers... They are supposed to push more air at lower rpms, and they are supposed to push even more air because the blade design is more efficient too. So one can logically surmise that these turbos aren't operating near 125krpm typically.

I did some quick calcs in this thread here and IIRC estimated rpm was around 85k rpm at full boost. These are big wheels so they dont need to spin that fast to push the required amount of air.

Regards to any clutch.. I havent even dared to think about how ypu would get a clutch on that thing (split turbochrger). Just never even thought I would need to imagine it. But i will give it a shot.

Stivala said sprag clutch.
How does this work when you switch directions from generator mode to motor mode?
We know that honda does "extra harvest" rapidly oscillating from generator mode to motor mode.. Can your clutch react fast enough without burning up?

What about stress concentrations? And whipping effect (vibrations) of a disk like mass (the clutch) on a long slender shaft at tens of thousands of rpm?
[/quote]

Have to go with Zealot here.
A Turbo has a max rotation speed limited by speed of the bladetips at the soundbarrier.

Hence an optimum rotation speed. Optimizing air pressure generated will make a difference. I recall the jet departement mentioned them redesigning the drive shaft gave Honda the biggest powergain.

A possibility would be the air at the turbo tips (towards the waste valve) are just breaking soundspeed when braking creating those 'bangs'.

[saviour stivala]

A torque converter fitted between an engine and an automatic gearbox drive is fitted with a ‘sprag type’ of one way clutch as otherwise there will be no engine breaking. In such a set-up, engine braking is as effective as could be. Either the engine is driving the gearbox or the gearbox is trying to drive the engine (engine braking).

[saviour stivala]

The turbocharger (Turbine) safe maximum RPM depends on the turbine diameter (tip blades speed). If the rotational speed (RPM) of the MGU-H being used is the maximum permitted (125000rpm) and the maximum rotational speed (RPM) of the turbocharger being used is less, the MGU-H have to be geared at the appropriate ratio. Example: MGU-K max rpm 50000 to crankshaft max rpm 15000 (and also may be clutched). This fixed speed ratio is achieved through the use of a tiny planetary gearbox, in the case of the split-turbo set-up with the MGU-H sitting in between the turbine and compressor, the gearbox would be at one end of MGU-H hollow drive/input shaft which the turbine/compressor shaft is passing through. And a sprag-type of one-way clutch will be the simplest and least complicated type of clutch to use.