Honda Power Unit Hardware & Software

[PlatinumZealot]

High end CFD software also have adaptive meshes these days too.

[godlameroso]

The mesh, or cells are where the calculations take place, for lack of a better term. The modeled combustion chamber is made up of many cells/meshes. CFD in it's purest form is simply each of these cells solving equations that describe the phenomena being studied.

The models used for these power units are unique as far as I can tell, and these engines are already ran so close to the edge that having a more accurate model, again, lets you run closer to the edge.

I'm not speaking in absolute terms, just wondering what Honda is up to this year.

As someone with experience with these power units do you suppose that valve angle is more critical than pre-chamber geometry, or piston crown shape to ultimate performance?

[godlameroso]

High end CFD software also have adaptive meshes these days too.

You're always limited by the equations governing your mesh, the ol' garbage in garbage out problem.

[Wazari]

Wazari wrote: ↑
FW17 wrote:
Hi Wazari
Are there any methods of flame quenching away from piston crown and cylinder walls currently being used in F1

What are the likely ways of achieving this?
1. I think I would assume so.
2. Various methods. CC design or lack of CC as we conventionally know it , piston groves, diagonal piston ports, slots, etc.

Just mulling over this, that's all. I could be way off, sure good meshes can be done in a day, but have them be as accurate with complex shapes and that afternoon can turn into a few months.

And I'm not talking about the thermodynamics that's child's play. I'm talking about the fuel reaction chemistry side of it. You can't develop your process if you can't see how your process influences the reactions. The 50hp gain from Mercedes wasn't just some exotic fuel blend, but understanding and being able to take advantage of the way the fuel combusts.

If you can model how fuel combusts more accurately than the next guy, you can run it closer to the edge of detonation.

The answer would be yes. Speaking from Honda's PU, there are very creative/innovative piston crown/ports being utilized.

Meshes......a few hours to a few months. Not as straight forward as some may think. How do you blend the data from each mesh? What do you do with the blended data. And most importantly, who is interpreting the data?

[63l8qrrfy6]

The models are not unique. High end CFD software offer bespoke IC models however most of them can handle any sort of combustion from gas turbines to boilers.

Some of the bespoke IC models such as the one provided by Ansys are actually pretty bad.

A decent cluster can solve 50 million polyhedron model with under 10 computing nodes with relative ease. At the end of the day if you can afford the computing power you can just use a brute force approach with ridiculously dense meshes.

I don't know much about the performance tradeoffs between valve angles, chamber geometry and piston crown as I mainly deal with mechanical design aspects. I don't see why valve angle would compete with prechamber geometry though.

As for piston crown, performance guys are very particular about the squish lands and crevice volumes. The valve characteristics dictate the piston pocket position and depth which significantly affects crown stressed and temperatures. Crevice volumes dictate ring groove height and land shape which affect ring temperature and wear. The challenge is to marry the performance requirements with the durability targets.

DOEs for performance parameters are normally conducted before the single cylinders are built. Once single cylinder testing has started only small adjustments are made. Unfortunately I don't know specifics about the entire process.

[kasio]

No actually, it doesn't make any sense.

What's the lead time on a carbon air box?

4-6 weeks.

What doesnt make sense is flat combustion chambers.

Why would it be even weeks? if You have to modify within known space and parameters?

[G'dayBruce]

This a Honda RFVC engine. Interestingly if you increase the dome height it will still allow for a relatively large cavity/cup atop the piston without interfering with even full valve pockets. Alternatively or depending on how 'out-there' you want to be you it also allows space to inject fuel through the piston if that's a thing... Or create a raised area the pushes air/fuel to the pre-chamber through a transfer port close to the injector.

*edit - The point being it'll open up alot of space in the head for placement of injectors/plugs.

http://4.bp.blogspot.com/-st15UChlTSc/V ... .01.16.jpg

http://1.bp.blogspot.com/-BBgX7FIfqbY/V ... G_7978.JPG

The good old rotary four valve configuration. I had this on a Honda GB250 back in my teens. Remember pulling the tappet cover off to get a look at how it was setup. Did they ever do it in anything other than a single? The packaging looks too bulky for a bank of cylinders, let alone an f1 engine. Said bike was hardly a power house either.

[63l8qrrfy6]

What's the lead time on a carbon air box?

4-6 weeks.

What doesnt make sense is flat combustion chambers.

Why would it be even weeks? if You have to modify within known space and parameters?

Of course if they can do it by altering existing tooling then it should be quite quick. I assumed new tooling is required.

[PlatinumZealot]

Wazari seems to be confident in this new engine. The bastard of the Spec 3 and Spec 4. Yet we are promised an even better engine half way into the season. Which one is team Wazari spec? The bastard or the one coming in the summer?

[loner]

the answer is half-life 3

[Wazari]

Wazari seems to be confident in this new engine. The bastard of the Spec 3 and Spec 4. Yet we are promised an even better engine half way into the season. Which one is team Wazari spec? The bastard or the one coming in the summer?

Spec 4.0 is the one that we specifically worked on with "our" designed combustion components. There really isn't a bastard version. Only the basic architecture remains the same. The physical dimensions remain fairly close. The two versions being tested now for the upcoming season are both Spec 4.0 based with upgrades. There is a completely "new" combustion process PU that is built but with almost zero running time at this moment. I assume that is the major mid-season planned PU. Also both "new" PU's have logged considerably more KM's than 2,500 without any major issues so I don't where this "only lasts 2,500 KM's" rumor is coming from.

[McMika98]

Spec 4.0 is the one that we specifically worked on with "our" designed combustion components. There really isn't a bastard version. Only the basic architecture remains the same. The physical dimensions remain fairly close. The two versions being tested now for the upcoming season are both Spec 4.0 based with upgrades. There is a completely "new" combustion process PU that is built but with almost zero running time at this moment. I assume that is the major mid-season planned PU. Also both "new" PU's have logged considerably more KM's than 2,500 without any major issues so I don't where this "only lasts 2,500 KM's" rumor is coming from.

Wazari, I suppose u cant elucidate on this new combustion design? maybe expounding limitation of TJI would be a good indicator. It seems this development was recent and not the same process used in 4.0 which quite frankly was last years contender. Do u think Honda can get to 1000hp peak this season? Would be remarkable and quite a turn around.

[Wouter]

....

[godlameroso]

When he says new, the principle is the same, but I'm guessing Honda has made some strides in understanding the chemical kinetics of the fuel. So new in the sense that a lot of features will have been modified to get the most out of this understanding.

The thermodynamics of an engine is easy, all that stuff is established, with enough validated programs that can get you in the ballpark. That's not what sets Mercedes apart. All the thermodynamic equations have a little modifier, omega, or for lack of a better term, where chemistry happens. Turns out that part is more complex, harder to model, and more important to the combustion process than all the other thermodynamic stuff.

But once you get this part right you can make much more predictive models than using thermodynamics alone, then you can start making serious gains.

Remember the ultimate difference in the power units isn't that big, and the difference comes from your development process. The better the models, the more you can safely design close to the edge. It's taken Honda some time but I believe sometime around the Russian GP 2016 Honda had the epiphany, and they've been slowly working on it since. I suppose this is what frightens manufacturers from entering, seeing how long it took Honda to become competitive, and seeing the money involved in getting there.

It's not so much a super secret fuel blend, it's understanding the fuel and the way it combusts with enough fidelity/resolution/accuracy that you can time your fuel injection, and spark timing, and design your pre-chamber/piston crown/etc better than the other guys.

[Wazari]

Spec 4.0 is the one that we specifically worked on with "our" designed combustion components. There really isn't a bastard version. Only the basic architecture remains the same. The physical dimensions remain fairly close. The two versions being tested now for the upcoming season are both Spec 4.0 based with upgrades. There is a completely "new" combustion process PU that is built but with almost zero running time at this moment. I assume that is the major mid-season planned PU. Also both "new" PU's have logged considerably more KM's than 2,500 without any major issues so I don't where this "only lasts 2,500 KM's" rumor is coming from.

Wazari, I suppose u cant elucidate on this new combustion design? maybe expounding limitation of TJI would be a good indicator. It seems this development was recent and not the same process used in 4.0 which quite frankly was last years contender. Do u think Honda can get to 1000hp peak this season? Would be remarkable and quite a turn around.

Well as they say, there is more than one way to skin a cat. This formula as we know presents many challenges. Fuel load and flow limits, and IMO the most challenging to achieve the highest power from the ICE is the injector pressure restriction. Where you can be creative is the air-fuel ratio, how its delivered and ignited with one injector and spark plug. I think we all can also agree that some configuration of a pre-chamber is necessary which houses the spark plug to keep the extremely difficult to ignite lean mixture away. So if you can figure out how pre-ignite a richer mixture with the spark plug to ignite the super lean mixture in the main chamber, while at same time running the highest compression ratio possible for power and max volume of exhaust gases for the turbine, then you have an ICE that potentially can produce 850 HP from 1.6 L. To achieve max exhaust volume/velocity, you want an outside to inside ignition pattern in the main chamber with plasma jets to reach the outside edges of the piston utilizing the pre-chamber.

So to achieve all those things, piston design has become the main focus along with chamber design, with intake design a close second IMO among all the manufacturers. The area where I think Honda will be unique is in the actual cylinder head routing of intake and exhaust gases and valve placement. I won't go into more detail at this time but maybe a point to ponder??