F1technical.net

If we can stick to that number, resulting in some 50 kW at 90% efficiency, my question is still what will a 100+ kRpm generator like that look like, does anyone have a vague idea of size and weight?

the weight is irrelevant ?
the minimum car weight rules mean that a car eg without an MGUH and associated systems must still carry the weight of these
as with the current rules and KERS

Hardly irrelevant at the position it is ruled to be at, while I find it surprising that none has raised this issue for 238 pages?

Teams go out on a limb to move a few kg south with adventurous pull-rod suspensions, but this?

WhiteBlue wrote:

ringo wrote:Something to think about for the MGUH.
If a turbine has 300hp available to do work and the compressor needs only 50hp. The MGUH can draw a maximum of 120kW with full batteries.
Both of these are loads on the turbine.
Do you think that if the turbine was spinning freely at 100k rpm, adding 120kW will somehow prevent the compressor from getting it's 50hp?
It may delay it once the torque of the MGUH is on the shaft, but it's going to creep up back and meet the load demands as long as that demand doesn't exceed 300hp.

That's the thing with the MGUH, it's a load, it's not pressure relief. Turbines operate on pressure difference. Mass flow must be manipulated to control enthalpy. In order to limit boost it must take a lion share of the available power leaving the compressor to take the scraps.
It's possible depending on how much available power is there, but i still see the waste gate as more viable and less complicated. chances are the MGU wont be able to control boost how we would like.

These figures are not consistent with your earlier computations, are they? Also 120 kW has never been discussed as a realistic load for the MGU-H. It is the peak power allowed for the kinetic machine. But we would not expect the heat regeneration to come close to that level, do we?

No this is just for example.

ringo wrote:

WhiteBlue wrote:

ringo wrote:Something to think about for the MGUH.
If a turbine has 300hp available to do work and the compressor needs only 50hp. The MGUH can draw a maximum of 120kW with full batteries.
Both of these are loads on the turbine.
Do you think that if the turbine was spinning freely at 100k rpm, adding 120kW will somehow prevent the compressor from getting it's 50hp?
It may delay it once the torque of the MGUH is on the shaft, but it's going to creep up back and meet the load demands as long as that demand doesn't exceed 300hp.

That's the thing with the MGUH, it's a load, it's not pressure relief. Turbines operate on pressure difference. Mass flow must be manipulated to control enthalpy. In order to limit boost it must take a lion share of the available power leaving the compressor to take the scraps.
It's possible depending on how much available power is there, but i still see the waste gate as more viable and less complicated. chances are the MGU wont be able to control boost how we would like.

These figures are not consistent with your earlier computations, are they? Also 120 kW has never been discussed as a realistic load for the MGU-H. It is the peak power allowed for the kinetic machine. But we would not expect the heat regeneration to come close to that level, do we?

No this is just for example.

So what do you think is the HP available on a "radial" not axial turbo for the MGUH after the compressor has taken its share???

I come up with 40HP compressor drive pressure and 40HP available for the MGUH with zero waste-gate flow. All of the exhaust going through the turbine!!!

@ WB You will not let 70hp run away through a waste gate all the time.
You have the MGUH to take 70hp when it can, throughout the rev range. I was focusing on the necessity of the boost controlling mode that is being considered.
If you cannot store the energy because the ES is full, your ancillaries are fully powered, and if the energy is more than 120kW then you have to let it run away.
There's nothing you can do.

having resistors in the MGU controller as a load to hog power that cannot be stored is even worse than letting the energy run out the tailpipe, because you are using heat to create heat, and creating back pressure and rising temperatures at the same time.

I keep manipulating my calculations so i'm not sure what i had up previously but lets work with this;

roughly about 200kW available from the turbine
The compressor will take 40kW off of that for the desired boost level. @ 10500rpm

Compressor demand will drop to around 20kW and available power from turbine will be 170kW at 15,000rpm

So boost control will be very dynamic i can imagine with using a motored load.

We need to realize that not every single drop of energy can be used. It sounds counter intuitive, but only so much can be retained, and for ultimate performance you may have to let some of it go if the car cannot store it.

From what i can see, i think the MGUH will be constantly driving the MKUK and thus the engine. 120kW is possible to be harvested most times, though this is ignoring the turbines speed and back pressure.

pgfpro wrote:
So what do you think is the HP available on a "radial" not axial turbo for the MGUH after the compressor has taken its share???

I come up with 40HP compressor drive pressure and 40HP available for the MGUH with zero waste-gate flow. All of the exhaust going through the turbine!!!

The MGUH will have a lot of energy available, but i think the turbine efficiency at certain speeds will have a big influence.
depends on how fast the turbine can react to load to steady itself to rated speed.

I think around 160kW is free for the taking, but the dynamics of the turbine as said above puts a question mark there.
But it's more than 40hp i think.
You can look on the MGUH as an additional compressor, only that the loading is going to be instant and not progressive like compressing air. I feel the engineers will have to find a way to progressively meter how the MGUH sees demand from the MGUK and batteries. these load rates will have to be controlled so as not to shock the turbine.

Behave gentlemen, what's it gonna be, 50 or 170 kW from the MGU-H. bit of a difference there?

Here's how I'm coming up with around 40 Hp recover after the compressor takes its amount.

Look at Borg Warner's Match Bot on plot 6 at 10500 rpm with the correct fuel limit entered.
Compressor Drive HP is 38.69 HP with a compressor efficiency of 76%. At this point the Calculated Percent Wastegating is 50.88% My simplistic mind tells me that it takes 38.69 HP to drive the compressor(exhaust going through the turbine). If 50.88% of the exhaust is being dump out the gate and you decided to use all of it and run it through the turbine then it would be another 38.69 HP???

http://www.turbodriven.com//performance ... rsin=92044&

ringo wrote: I think around 160kW is free for the taking, but the dynamics of the turbine as said above puts a question mark there.
But it's more than 40hp i think.
You can look on the MGUH as an additional compressor, only that the loading is going to be instant and not progressive like compressing air. I feel the engineers will have to find a way to progressively meter how the MGUH sees demand from the MGUK and batteries. these load rates will have to be controlled so as not to shock the turbine.

to be blunt, why has this never been done before in other applications (if there is 160 kW free for the taking) ??
surely you can only take 160 kW from the turbine at the cost of raising the back pressure and therby losing a lot of crankshaft power ?
textbooks say this can improve efficiency rather than (combined) power, and is more a diesel than a spark ign thing
you can go even further and produce a free-piston engine (no crankshaft), this may be coming back (now with linear generators)

Wright showed they had no back pressure (on the exhausting upstroke), so lost no crankshaft power
ie were only recovering from the blowdown exhaust pulse
they had done relatively little expansion with low CR and very early exhaust valve opening (lots of low-hanging fruit)

the beauty of the MGUH is the continuous (ie smooth and progressive) transition from motoring to recovery and back
the inner control loop would be rpm, the overall demand would be programmed and measured pressure etc
yes it would need development

xpensive wrote:Behave gentlemen, what's it gonna be, 50 or 170 kW from the MGU-H. bit of a difference there?

170kW is what's left after the compressor takes it share. The MGUH may be able to take most of that in theory.
If the MGUH takes that, you are looking at 400 degrees C exhaust temps.
I'm gonna have to dig up some text books and old turbine calculations i did some years ago to see what really happens.
Should be able to see what happens with that remaining 170kW.

I'm going to look on that borg warner thing too.

pgfpro wrote:Here's how I'm coming up with around 40 Hp recover after the compressor takes its amount.

Look at Borg Warner's Match Bot on plot 6 at 10500 rpm with the correct fuel limit entered.
Compressor Drive HP is 38.69 HP with a compressor efficiency of 76%. At this point the Calculated Percent Wastegating is 50.88% My simplistic mind tells me that it takes 38.69 HP to drive the compressor(exhaust going through the turbine). If 50.88% of the exhaust is being dump out the gate and you decided to use all of it and run it through the turbine then it would be another 38.69 HP???

http://www.turbodriven.com//performance ... rsin=92044&

They gave a waste gate area, i think the waste gating % has to do with how much it is open? 100% would be fully open.

I strongly believe that the F1 engineers will be clever about getting as much out of the exhaust heat that you reasonably can which would include using axial turbines with higher efficiency if that proves to be an advantage in total power available. So we can expect something higher than 40 kW but lower than 120 kW. There is a purpose why the MGU-K was set for that power level. Everything that we have so far leaned indicates that there will not be a full contingent of electric energy to run the MGU-K at full song all the time when you have WOT. It follows that the MGU-H must have less than 120 kW. I would find it much more logical to look at something in the magnitude of 80-100 kW. That would leave some headroom and make it unnecessary to regularly use a waste gate to get rid of surplus energy.

The MGU-H will obviously not be primarily controlled in an energy guided mode but in a turbine balancing mode. The produced energy will be incidental and the energy management system must look after utilizing it appropriately or in the best way to generate performance. It has a buffer capacity which is contained in the battery for that purpose and it has an augmenting generating capacity from the kinetic recovery.

Would this type of charger be legal?? I believe its still a single stage turbo :

http://turbo.honeywell.com/whats-new-in ... opup=video

It has axial flow turbine. And double sided compressor wheel. The double sided compressor wheel is what makes me question its legality?? Though they are not two different sizes which I guess would make it single stage.

The design of the intake on this turbo reminds me of the wired round intake on the Renault engine pictures. It has this round shape right in front of the compressor housing :



More on the honywell turbo :
http://turbo.honeywell.com/our-technolo ... ochargers/

That is a neat looking turbo design, I can't see how the exhaust turbine would be illegal but knowing the FiA it's possible they could find some rubbish way to declare a double sided compressor as illegal.