Ferrari Power Unit Hardware & Software

All that has to do with the power train, gearbox, clutch, fuels and lubricants, etc. Generally the mechanical side of Formula One.
gruntguru
438
Joined: Sat Feb 21, 2009 6:43 am

Re: Ferrari Power Unit Hardware & Software

Post by gruntguru » Tue Nov 12, 2019 12:42 am

saviour stivala wrote:
Mon Nov 11, 2019 7:10 pm
The scope of providing the high pressure fuel pump inlet with a low pressure fuel supply from an accumulator (collector pot) which is pressurized at low pressure is to eliminate aeration from the fuel supplied to the high pressure pump.
Note to all.

The collector-pot, surge tank, swirl pot etc is NOT an accumulator in the sense of a hydraulic pressure accumulator. Use of the term "accumulator" in this thread should be restricted to that definition ie a pressure/volume accumulator post flow-meter which could be used to temporarily exceed the 100 kg/hr fuel flow limit.
je suis charlie

gruntguru
438
Joined: Sat Feb 21, 2009 6:43 am

Re: Ferrari Power Unit Hardware & Software

Post by gruntguru » Tue Nov 12, 2019 12:48 am

godlameroso wrote:
Mon Nov 11, 2019 1:57 pm
henry wrote:
Sun Nov 10, 2019 10:48 am
saviour stivala wrote:
Sun Nov 10, 2019 5:10 am
The formula one ‘return-less’ fuel flow system (fuel transfer from fuel tank to engine combustion chambers) as in use at the present 2019 season.
Electrically driven low pressure lift pumps >> pressurized collector pot >> fuel flow sensor/meter >> high pressure mechanical engine driven pump >> fuel rail >> injectors.
Have you been able to find a source for this assertion? Why do you think the FIA have decided to enforce a different system for 2021?
This is how all high pressure fuel systems work. This being a direct injection fuel system requires a secondary mechanical pump to raise line pressure. The electric pickup pump is rated between 30-40psi, to get to 500psi requires the fuel be re-pressurized. This requires an accumulator as backflow would damage the electric pump.

The measurement point is in the "low pressure side" simply because it is closer to the fuel flow point of origin. It's not practical to place it upstream because of the accumulator required to raise line pressure.
Why would there be "backflow"? There is no need for an accumulator IMO.
je suis charlie

henry
242
User avatar
Joined: Mon Feb 23, 2004 7:49 pm
Location: England

Re: Ferrari Power Unit Hardware & Software

Post by henry » Tue Nov 12, 2019 10:05 am

Since there is no return for the fuel the flow the FFS sees is only the flows from the injectors. This is anything but steady with peaks when injecting and no flow when not. I would expect the peaks would be much greater than 100kg/hr and the FFS would register them, since the FFS sampling frequency is higher than likely “frequency” of injector events. There must be some process somewhere that sums the FFS samples and averages them to get the value needed for management.

So the FFS is seeing cyclic input and cyclic output. I wonder if it would be possible to trim the peaks by having minimum input coincide with maximum output.
Fortune favours the prepared; she has no favourites and takes no sides.
Truth is confirmed by inspection and delay; falsehood by haste and uncertainty : Tacitus

saviour stivala
-13
Joined: Wed Apr 25, 2018 11:54 am

Re: Ferrari Power Unit Hardware & Software

Post by saviour stivala » Tue Nov 12, 2019 10:44 am

All fuel that have passed through the fuel flow sensor/meter would have been accurately registered to a degree the same for all. All of this fuel will end up into the combustion chambers because the system is return-less. The fuel flow sensor/meter does not in any way restrict the flow passing through it. The management of what ends up in the combustion chambers is the responsibility of the engine fuel management software. If this software allows more fuel flow to end up into the combustion chambers than that allowed by the rules, there is no escaping an approved and untampered-with fuel flow sensor/meter correct reading. It is ironic and amusing that all those on here that participated on the “10500 RPM max power speed” forum pages are not disputing the fact that whoever manages to circumvent the fuel flow rules over and above what the rules allows (max 100kg/h at 10500rpm) and so manages to have more fuel ending-up into the combustion chambers will have a power output advantage.

NL_Fer
63
Joined: Sun Jun 15, 2014 8:48 am

Re: Ferrari Power Unit Hardware & Software

Post by NL_Fer » Tue Nov 12, 2019 2:19 pm

I remember they used to inject over 100kg/hr and compensated by dropping rail pressure to keep the tank flow below 100kg/hr.

FIA warned them about the rail pressures jumping up and down. I suspect they found ways to buffer some fuel with rail pressure staying within margins.

Like wings are not allowed to bend, still they do move, just within the allowed margin.

djones
12
Joined: Thu Mar 17, 2005 2:01 pm

Re: Ferrari Power Unit Hardware & Software

Post by djones » Tue Nov 12, 2019 7:15 pm

I think Honda and Redbull have some very clever people and if they are saying the extra power is coming from sensor manipulation, then there is probably a 95% chance this is actually the reason behind it.

Personally I suspect we will see less engine performance from now full stop. What I think will be interesting is to see what excuse Ferrari will give in order to say the decrease is something else and it's just a coincidence.

LM10
59
Joined: Tue Mar 06, 2018 11:07 pm

Re: Ferrari Power Unit Hardware & Software

Post by LM10 » Tue Nov 12, 2019 10:25 pm

djones wrote:
Tue Nov 12, 2019 7:15 pm
I think Honda and Redbull have some very clever people and if they are saying the extra power is coming from sensor manipulation, then there is probably a 95% chance this is actually the reason behind it.

Personally I suspect we will see less engine performance from now full stop. What I think will be interesting is to see what excuse Ferrari will give in order to say the decrease is something else and it's just a coincidence.
You mean like last year when very clever people from Mercedes were sure that Ferrari was doing something wrong?
Last edited by LM10 on Tue Nov 12, 2019 10:48 pm, edited 1 time in total.

gruntguru
438
Joined: Sat Feb 21, 2009 6:43 am

Re: Ferrari Power Unit Hardware & Software

Post by gruntguru » Tue Nov 12, 2019 10:42 pm

henry wrote:
Tue Nov 12, 2019 10:05 am
Since there is no return for the fuel the flow the FFS sees is only the flows from the injectors. This is anything but steady with peaks when injecting and no flow when not. I would expect the peaks would be much greater than 100kg/hr and the FFS would register them, since the FFS sampling frequency is higher than likely “frequency” of injector events. There must be some process somewhere that sums the FFS samples and averages them to get the value needed for management.

So the FFS is seeing cyclic input and cyclic output. I wonder if it would be possible to trim the peaks by having minimum input coincide with maximum output.
I addressed this in an earlier post.
Of course we are talking about a very small quantity of storage (accumulation) at moderately high frequency eg at 10,500 rpm (and assuming one injection pulse per intake event)
- Fuel qty/cylinder = 0.053g
- frequency of injection events = 525 Hz

A very small accumulator on the fuel rail or even the flexibilty of the lines and fuel would be sufficient to damp these fluctuations so they were invisible to the flow sensor. AFAIK the FIA has defined what constitutes acceptable accumulation for these purposes.
je suis charlie

henry
242
User avatar
Joined: Mon Feb 23, 2004 7:49 pm
Location: England

Re: Ferrari Power Unit Hardware & Software

Post by henry » Tue Nov 12, 2019 11:13 pm

gruntguru wrote:
Tue Nov 12, 2019 10:42 pm
henry wrote:
Tue Nov 12, 2019 10:05 am
Since there is no return for the fuel the flow the FFS sees is only the flows from the injectors. This is anything but steady with peaks when injecting and no flow when not. I would expect the peaks would be much greater than 100kg/hr and the FFS would register them, since the FFS sampling frequency is higher than likely “frequency” of injector events. There must be some process somewhere that sums the FFS samples and averages them to get the value needed for management.

So the FFS is seeing cyclic input and cyclic output. I wonder if it would be possible to trim the peaks by having minimum input coincide with maximum output.
I addressed this in an earlier post.
Of course we are talking about a very small quantity of storage (accumulation) at moderately high frequency eg at 10,500 rpm (and assuming one injection pulse per intake event)
- Fuel qty/cylinder = 0.053g
- frequency of injection events = 525 Hz

A very small accumulator on the fuel rail or even the flexibilty of the lines and fuel would be sufficient to damp these fluctuations so they were invisible to the flow sensor. AFAIK the FIA has defined what constitutes acceptable accumulation for these purposes.
Sorry. Missed it.

Is the fuel qty right? I calculated 0.096 g based on 12000rpm, 3 injection events per rpm/sec.

Edit: you are right. Redid my calc and it’s in line with your value. Apologies for doubting.

However a further point is the the fuel quantity isn’t delivered over the whole of the available time. I don’t know what proportion of a rev an injection cycle takes, or how many there are, but my assumption is that fuel quantity is delivered in a shorter period than simple calculation of the time for 1/3 of a rev. A consequence of this is that the instantaneous flow rate will be higher than the average permitted, potentially much higher. But there will also be periods where there is zero delivery.

The FFS samples at a high enough rate to mean that it will see both these very high rates and the zero rates. Consequently it will need to hand its sample numbers to a downstream process that calculates the average and checks it is compliant.

Some other issues are that firing order is not even, and that as well as the very unsteady nature of the output from the FFS the input is also potentially unsteady due the primer pump frequencies.

As you say the limited accumulator volume mean the FFS must see these variations.
Fortune favours the prepared; she has no favourites and takes no sides.
Truth is confirmed by inspection and delay; falsehood by haste and uncertainty : Tacitus

saviour stivala
-13
Joined: Wed Apr 25, 2018 11:54 am

Re: Ferrari Power Unit Hardware & Software

Post by saviour stivala » Wed Nov 13, 2019 9:46 am

Before the engine is started the fuel collector pot would have to be pressurized by fuel (low pressure) by the lifter pumps. Only then can fuel flow through the fuel flow sensor/meter and into the high pressure pump intake. And only after that can the high pressure pump pressures (high pressure) the fuel rail and injectors.
At maximum allowed fuel flow (100kg/h at 10500rpm) the engine is making 525 combustions per second with each combustion using 0.0529 grams of fuel. The fuel flow sensor/meter can flow 8-litres/min – 480-litres/h. The fuel flow sensor/meter measures fuel flow through it 4000 times per second.

Polite
7
Joined: Tue Oct 30, 2018 9:36 am

Re: Ferrari Power Unit Hardware & Software

Post by Polite » Wed Nov 13, 2019 12:22 pm

<For the record, since the user asked: This and the other missing posts were, indeed off topic.
Hardware here. Politics not here. Simples.>


edit: Sorry admins! i will!

subcritical71
72
User avatar
Joined: Tue Jul 17, 2018 7:04 pm
Location: USA-Florida

Re: Ferrari Power Unit Hardware & Software

Post by subcritical71 » Wed Nov 13, 2019 8:09 pm

henry wrote:
Tue Nov 12, 2019 11:13 pm
The FFS samples at a high enough rate to mean that it will see both these very high rates and the zero rates. Consequently it will need to hand its sample numbers to a downstream process that calculates the average and checks it is compliant.

Some other issues are that firing order is not even, and that as well as the very unsteady nature of the output from the FFS the input is also potentially unsteady due the primer pump frequencies.

As you say the limited accumulator volume mean the FFS must see these variations.
There has to be some allowed accumulation as well as FFS sample averaging. The fuel pump could not be expected to cycle at that high a rate to maintain rail pressure without it.

I did find that the FlowSonic Elite sensor (https://www.sentronics.com/wp-content/u ... etMSDS.pdf) has a sampling rate of 2.2kHz, but more interesting to me is that it only has a measurement range of 0.5 to 8L/min. The 8L/min (480L/hr or ~360kg/hr) definitely falls in the range where it is greater than regulated max fuel flow. However, the 0.5L/min (30L/hr or ~22.5kg/hr) seems like it would be too high for the lower end of the PU operating range(?)

NL_Fer
63
Joined: Sun Jun 15, 2014 8:48 am

Re: Ferrari Power Unit Hardware & Software

Post by NL_Fer » Wed Nov 13, 2019 9:16 pm

To Low is not a problem right?

zibby43
262
Joined: Sat Mar 04, 2017 11:16 am

Re: Ferrari Power Unit Hardware & Software

Post by zibby43 » Wed Nov 13, 2019 9:16 pm


MtthsMlw
690
User avatar
Joined: Wed Jul 12, 2017 5:38 pm
Location: Germany

Re: Ferrari Power Unit Hardware & Software

Post by MtthsMlw » Wed Nov 13, 2019 9:36 pm

With some more on the way apparently :D