Honda 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.
kasio
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Re: Honda Power Unit Hardware & Software

Post by kasio » Tue Nov 13, 2018 9:52 pm

godlameroso wrote:
Tue Nov 13, 2018 5:59 pm
Why would less fuel react faster than more fuel?
yes! with practical analogy when burning wood in stove. if you let a lot of oxigen in it burns slmost like a rocket. so yes more oxygen would make reaction faster.

saviour stivala
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Re: Honda Power Unit Hardware & Software

Post by saviour stivala » Tue Nov 13, 2018 10:37 pm

Tommy Cookers wrote:
Tue Nov 13, 2018 3:35 pm
saviour stivala wrote:
Tue Nov 13, 2018 12:40 pm
The resultant fast flame speed when TJI combustion system is used that reduces the need for much ignition advance ...
......A faster combustion (time wise) is not necessary a stronger and more complete combustion than a slower combustion, again (time wise).......The previous 2.4L NA V8 ....at that time teams were using both fast burn formulated fuel as well as slow burn, depending on circuit specifics. In both cases (both types of ICE) the ignition advance used is solely aimed to move the maximum combustion pressure point to 14 degrees ATDC power stroke.
the TJI etc is for use with abnormally lean (so slow burning) mixtures - (how) would it need less advance than the conventional ?
some may soon be claiming that TJI cures cancer and turns water into wine

the 2.4 V8s didn't use fast burning fuel and slow burning fuel
they used fast burning fuel where rather low volume-specific or mass-specific heat content was tolerable
and rather fast burning fuel where a higher volume-specific or mass-specific heat content was required
they used 60 deg or more ignition advance

btw (V10? F1 Ferrari tests in a measurement journal) had inconsistent combustion in some cylinders unless plenty rich
Mahle jet ignition:- "The main charge is extensively ignited and a faster burn-through and presure build-up is generated".
During the NA 2.4L V8 era fast burn as well as slow burn fuel formulated in acordance as per regulations was being used depending on cercuits specifics.

saviour stivala
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Re: Honda Power Unit Hardware & Software

Post by saviour stivala » Tue Nov 13, 2018 11:03 pm

In an ICE when the ‘fire’ is lit it is a burn-not an explosion (that would be like detonation). As the RPM increases there is less time for maximum cylinder pressure to be reached at the right place in piston travel (crank degrees). So the ‘fire’ is lighted sooner to get max pressure at the right place/time.

godlameroso
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Re: Honda Power Unit Hardware & Software

Post by godlameroso » Tue Nov 13, 2018 11:30 pm

That only works with a rich mixture, adding unreactive air to a lean mixture has the same effect as diluting the AF mixture with EGR.
The height of cultivation is really nothing special. It is merely simplicity; the ability to express the utmost with the minimum. Mr.Lee

saviour stivala
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Re: Honda Power Unit Hardware & Software

Post by saviour stivala » Wed Nov 14, 2018 9:54 am

When the mean PPP (peak pressure position) is not optimum the variations in the output torque are minimal. When the optimum PPP lies some degrees off from optimum the resulting output torque variations are larger. PPP is the position in crank angle for pressure peak (pressure peak position).
Different ignition angles for different engine speed and load changes the laminar burning velocity as well as the flame angle and flame speed.
In the NA 2.4L V8 era both fast burn and slow burn fuel was being formulated and used according to circuit specifics needs, these fuels were formulated to FIA fuel regulations specifications. Different fuels formulation use between races I believe are not permitted by the rules nowadays. Anyhow the technical benefit results of those efforts only the fuel formulator and the user could tell, but it is worth mentioning a particular test comparison and it’s results between F1 formulated fuel and that formulated for normal road car use of which both are as per FIA fuel formulation. In 2011 FERRARI/Shell used a 2 year old (2009) as per FIA testing regulations FERRARI F1 F60 with its tipo 056 2.4L NA V8 Driven by Alonso at Fiorano. 4 laps ran using FI fuel resulted in a best lap time of 1:03.950. 4 laps ran using Shell normal road pump fuel resulted in a best lap time 9/10ths slower but the road pump fuel produced a faster top speed. These finding were shown in telemetry recordings for all to see at the time.

henry
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Re: Honda Power Unit Hardware & Software

Post by henry » Wed Nov 14, 2018 10:47 am

Here’s a presentation by Mahle on a project they did for the US government.https://www.energy.gov/sites/prod/files ... 2015_o.pdf

It discusses low speed, 2500 rpm operation. It, I think, gives some insight, but not definitive answers, into some of the discussion points on TJI.

On injection it says the injection event into the pre-chamber is >60° BTDC.

On ignition it says the prechamber ignites and then there is a delay before the jets are formed and the main chamber ignites. So essentially we have 2 ignition events to discuss. The first graph shows these at 25° and 9° BTDC respectively. I’ll leave those more knowledgeable to comment on whether this is early or late in comparison with normal spark ignition.

It shows max cylinder pressure at around 13-14° ATDC. I’m guessing this has informed @Saviour stivala’s assertions.

The importance of free radicals in the ignition jet is mentioned, supporting some of @godlamerosa’s points.

There is brief discussion at the end of the issue of fouling of the jet orifices. It’s claimed not to be observed as an issue. I wonder that if the chamber is formed as part of the spark plug insert whether it can be removed and replaced? This might allow more and smaller jets than the 4 or 6 mentioned in this project.
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Polite
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Re: Honda Power Unit Hardware & Software

Post by Polite » Wed Nov 14, 2018 11:18 am

henry wrote:
Wed Nov 14, 2018 10:47 am
Here’s a presentation by Mahle on a project they did for the US government.https://www.energy.gov/sites/prod/files ... 2015_o.pdf

It discusses low speed, 2500 rpm operation. It, I think, gives some insight, but not definitive answers, into some of the discussion points on TJI.

On injection it says the injection event into the pre-chamber is >60° BTDC.

On ignition it says the prechamber ignites and then there is a delay before the jets are formed and the main chamber ignites. So essentially we have 2 ignition events to discuss. The first graph shows these at 25° and 9° BTDC respectively. I’ll leave those more knowledgeable to comment on whether this is early or late in comparison with normal spark ignition.
Very nice link, tnk u!

saviour stivala
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Re: Honda Power Unit Hardware & Software

Post by saviour stivala » Wed Nov 14, 2018 11:52 am

The Mahle project presentation done for US Government was actually the one that convinced me that their TJI combustion system was not compatible with the needs of an engine that spends most of its working life rotating at a maximum power speed of 10500 RPM. That is apart from my opinion that it is also not compatible with FIA direct injection rules. But on the other hand it had nothing to do with my believed technical opinion that:- fuel in this here DISI ICE is injected at least 60 degrees BTDC. That maximum combustion pressure (PPP-peak pressure position) is at optimum when reached at 14 degrees ATDC (and an note here, this PPP most benefic position point goes for most engines I know off and have been around.
A post explaining all about ‘PPP’ has been posted a while back but still have to pop-up.

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Re: Honda Power Unit Hardware & Software

Post by saviour stivala » Wed Nov 14, 2018 11:56 am

As I submitted my reply post to henry the mentioned PPP post just popped-up.

dren
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Re: Honda Power Unit Hardware & Software

Post by dren » Wed Nov 14, 2018 12:15 pm

saviour stivala wrote:
Wed Nov 14, 2018 9:54 am
Different fuels formulation use between races I believe are not permitted by the rules nowadays.
Fuel suppliers bring fuel upgrades throughout the season.

TC had some good insight as to how they went about fuel formulation in the older non-hybrid formula a page or so back.

Thanks to henry for the article. I think some of us are confusing igniting the pre-chamber vs igniting the main lean charge when talking about ignition timing.
Honda!

Tommy Cookers
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Re: Honda Power Unit Hardware & Software

Post by Tommy Cookers » Wed Nov 14, 2018 12:40 pm

saviour stivala wrote:
Wed Nov 14, 2018 9:54 am
.... In the NA 2.4L V8 era both fast burn and slow burn fuel was being formulated and used according to circuit specifics needs, .....mentioning a particular test comparison and it’s results between F1 formulated fuel and that formulated for normal road car use of which both are as per FIA fuel formulation... FERRARI F1 F60 with its tipo 056 2.4L NA V8 Driven by Alonso at Fiorano. 4 laps ran using FI fuel resulted in a best lap time of 1:03.950. 4 laps ran using Shell normal road pump fuel resulted in a best lap time 9/10ths slower but the road pump fuel produced a faster top speed.......
road fuel being 1.5% worse on laptime might suggest that (presumably the 'worst' version) NA F1 fuel wasn't slow burning
and the road fuel was an expensive version intended for sporty cars so might have been faster burning than the usual road fuel
despite the usual assumption that the higher the ON the slower the combustion

current F1 fuel has presumably the highest possible mass-specific heat content and ON regardless of other properties

saviour stivala
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Re: Honda Power Unit Hardware & Software

Post by saviour stivala » Wed Nov 14, 2018 2:14 pm

Tommy Cookers wrote:
Wed Nov 14, 2018 12:40 pm
saviour stivala wrote:
Wed Nov 14, 2018 9:54 am
.... In the NA 2.4L V8 era both fast burn and slow burn fuel was being formulated and used according to circuit specifics needs, .....mentioning a particular test comparison and it’s results between F1 formulated fuel and that formulated for normal road car use of which both are as per FIA fuel formulation... FERRARI F1 F60 with its tipo 056 2.4L NA V8 Driven by Alonso at Fiorano. 4 laps ran using FI fuel resulted in a best lap time of 1:03.950. 4 laps ran using Shell normal road pump fuel resulted in a best lap time 9/10ths slower but the road pump fuel produced a faster top speed.......
road fuel being 1.5% worse on laptime might suggest that (presumably the 'worst' version) NA F1 fuel wasn't slow burning
and the road fuel was an expensive version intended for sporty cars so might have been faster burning than the usual road fuel
despite the usual assumption that the higher the ON the slower the combustion

current F1 fuel has presumably the highest possible mass-specific heat content and ON regardless of other properties
if interested in that fuel comparison test try trace and viste "how close is F1 fuel to road car fuel//F1 news//james allen on F1" also "shell v-power race fuel vs shell v-power road fuel" at that time the test was also futured no "BBC-Jake Hmphery shell v-power fuel test".

saviour stivala
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Re: Honda Power Unit Hardware & Software

Post by saviour stivala » Fri Nov 16, 2018 9:24 am

Mixture burn time versus engine speed. The time for an overall burn.
Standard road car at near max power (4000 RPM) 2.1 ms burn time.
Formula 1 car (NA V8 at max power (19000 RPM) 0.4 ms burn time.
How does the flame burn all mixture in the cylinder at high engine speed?, the turbulent intensity increase with piston speed, the turbulent burning velocity is proportional to the turbulent intensity. At higher engine speeds the turbulent velocity is also higher, less time is needed to burn the entire mixture.

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Re: Honda Power Unit Hardware & Software

Post by PlatinumZealot » Fri Nov 16, 2018 4:16 pm

saviour stivala wrote:
Tue Nov 13, 2018 12:40 pm
The resultant fast flame speed when TJI combustion system is used that reduces the need for much ignition advance is the result of the main combustion chamber contents being ignited by a fast flame that is the result of an already combusted small content by a spark plug inside a pre-chamber. But talking about such technical matters regarding high speed operation of a F1 engine the following should be born in mind. A faster combustion (time wise) is not necessary a stronger and more complete combustion than a slower combustion, again (time wise). The present 1.6L T V6 ICE spending most of its racing life at a max power speed of 10500RPM fires all 6 cylinders 5250 times in one minute. The previous 2.4L NA V8 spending most of its racing life at a max power speed of 17500RPM used to fire all 8 cylinders 8750 time in one minute, at that time teams were using both fast burn formulated fuel as well as slow burn, depending on circuit specifics. In both cases (both types of ICE) the ignition advance used is solely aimed to move the maximum combustion pressure point to 14 degrees ATDC power stroke.
Slower combustion is not really an option. How the TJI makes up for "completeness" by utilizing multiple jets travelling radially outwards like a star shape to emmulate a near homogenous combustion. It's a pretty neat trick.
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saviour stivala
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Re: Honda Power Unit Hardware & Software

Post by saviour stivala » Fri Nov 16, 2018 8:20 pm

PlatinumZealot wrote:
Fri Nov 16, 2018 4:16 pm
saviour stivala wrote:
Tue Nov 13, 2018 12:40 pm
The resultant fast flame speed when TJI combustion system is used that reduces the need for much ignition advance is the result of the main combustion chamber contents being ignited by a fast flame that is the result of an already combusted small content by a spark plug inside a pre-chamber. But talking about such technical matters regarding high speed operation of a F1 engine the following should be born in mind. A faster combustion (time wise) is not necessary a stronger and more complete combustion than a slower combustion, again (time wise). The present 1.6L T V6 ICE spending most of its racing life at a max power speed of 10500RPM fires all 6 cylinders 5250 times in one minute. The previous 2.4L NA V8 spending most of its racing life at a max power speed of 17500RPM used to fire all 8 cylinders 8750 time in one minute, at that time teams were using both fast burn formulated fuel as well as slow burn, depending on circuit specifics. In both cases (both types of ICE) the ignition advance used is solely aimed to move the maximum combustion pressure point to 14 degrees ATDC power stroke.
Slower combustion is not really an option. How the TJI makes up for "completeness" by utilizing multiple jets travelling radially outwards like a star shape to emmulate a near homogenous combustion. It's a pretty neat trick.
Agree that the Mahle TJI produces a near homogenous main (2nd) combustion by utilizing multiple flame jets produced by the 1st combustion which is started in a pre-chamber by means of a spark plug.