Honda Power Unit Hardware & Software

[Joseki]

Wazari-San and others more knowledgable on vibration related issues than me. Can how and the points of where the turbocharger is mounted to the PU as well as the PU being mounted in the car instead of on a dyno or flow bench change the resonant frequency?

One thought I am having is the ICE is mounted directly to the chassis, transmission and other parts of the car. When the ICE is running it will have particular vibration characteristics that will be different than when it is mounted to a dyno. Correct? Now how would these different vibration levels and frequencies affect he turbocharger shaft when it itself has its own vibrations?

I don't know if I'm more knowledgeable on vibration issues than you. Any object affixed to a moving part or a part housing moving part(s) is going to act as a dampener for that item. Obviously the size and material of the dampening agent will have an effect on vibration levels. However, I think it's important to first examine is the vibration a symptom of a fault or is it causing a fault. In my experience, vibration from the turbocharger itself was never an issue.

I think most here are talking about vibrations causing a failure. I can't see the resonance from the internals of the turbocharger itself being an issue but when you start attaching moving parts to a turbo then I can see the potential of vibrations being a symptom of a "fault". The vibration might accelerate the ultimate failure of the part, but usually it's a design or material flaw that causes the undesirable vibration. When a driver complains of a vibration it's always a symptom of a fault.

I guess what I'm trying to say is that the vibration itself is usually not the problem but it's the cause of the vibration that's the real issue. Some hot rodders put these IMO crazy duration camshafts with high valve lifts to intentionally cause vibrations or shaking. Does that in itself cause any damage to the engine, typically no. However, the vibration might cause interior pieces to rattle and come loose as a by-product. So going back to the F1 PU, someone mentioned Merc having vibrations with their long connection from turbo to MGU-H. The vibrations itself might be a nuisance but was it the cause of the vibration or the result of accelerated wear/failure from the vibration that was the real issue; could be both.

Wazari-san I have a question regarding how Honda test the power unit at Sakura: Ferrari, Mercedes and Red Bull/Renault (back in the days when they were a united group) use the AVL dyno to test the PU on the car, do Honda have such kind of technology? And if they don't, do they plan to upgrade the facility?

On the official website I've found something similar to an AVL dyno at Sakura but not so advanced:

AVL at Maranello



Dyno at Sakura




Here in Italy many engineers believe Ferrari closed the gap during the season to Mercedes thanks to this kind of technology.

[gruntguru]

Does any one reckon that's a dummy impeller?

Doesn't look like a 3D CFD solver has optimised it to the last micron does it?

I would say it is the real thing. Doesn't look unusual to me. Even has balance marks etc.

[aterren]

What does Wazari mean in Japanese? I guess it is not your real name Wazari.

Actually the word is waza-ari which loosely translated means almost perfect or almost a knock out. I just shortened to wazari for user name purposes. It's a scoring term most common used in judo. My real first name is Mitsuru.

By any name you have made some of my favorite posts of the season. Thank you.

[pgfpro]

After spending some time looking at pic #1 I think the turbine wheel is around a 85mm ind with a 76mm exd.

I also think its a RFT turbine and not a MFT turbine.

I'm also seeing that the waste gate is operating a lot more then I would have thought (exhaust soot wash) Ringo was correct.lol

Also I think you can see some details of the MGU H and some loading on the outside of turbine wheel?

Anyway i think Honda is going to make some major changes next year so they don't really care about people taking pics up close;)

[Wazari]

Wazari-san I have a question regarding how Honda test the power unit at Sakura: Ferrari, Mercedes and Red Bull/Renault (back in the days when they were a united group) use the AVL dyno to test the PU on the car, do Honda have such kind of technology? And if they don't, do they plan to upgrade the facility?

On the official website I've found something similar to an AVL dyno at Sakura but not so advanced:

AVL at Maranello
http://pbs.twimg.com/media/CFhLj4WWIAAkdwq.jpg


Dyno at Sakura
http://world.honda.com/RandD/hrd_sakura ... ura_09.jpg



Here in Italy many engineers believe Ferrari closed the gap during the season to Mercedes thanks to this kind of technology.

I don't know if I understand your question. AVL is a manufacturer of dynos. I'm sure they have comparable equipment if not AVL equipment???

[FW17]

I think the question is if Honda has a chissis dyno inside a climate wind tunnel.

And have they tested an Mclaren f1 car in it.

[Brian Coat]

Does any one reckon that's a dummy impeller?
Doesn't look like a 3D CFD solver has optimised it to the last micron does it?

I would say it is the real thing. Doesn't look unusual to me. Even has balance marks etc.

Thanks. Good point re balance marks.
I think I was (over) influenced by this end view of a (150,000+rpm) WRC turbine - with its subtle curvature and curl at the trailing edge, it just "looked" a bit more optimised.
http://imgur.com/yKet8cv

[Joseki]

I don't know if I understand your question. AVL is a manufacturer of dynos. I'm sure they have comparable equipment if not AVL equipment???

I think the question is if Honda has a chissis dyno inside a climate wind tunnel.

And have they tested an Mclaren f1 car in it.

Exactly.

[Tommy Cookers]

....Any object affixed to a moving part or a part housing moving part(s) is going to act as a dampener for that item. .........
..... going back to the F1 PU .... Merc having vibrations with their long connection from turbo to MGU-H.

......Some hot rodders put these IMO crazy duration camshafts with high valve lifts to intentionally cause vibrations or shaking

with apologies for editing the quote .....
yes, as has been said, presumably parts of the system are operating above their whirling-critical rpm ('resonance')
and (we are reminded) attached objects eg armatures and turbines actually raise and 'soften' the critical rpm via gyroscopic effects
the system must pass very quickly through these rpm (another deterrent to designing for only gu-h action ?)
this reminds me that I once designed something to run at its critical rpm (though for less than a second in a week's running)

attached objects of course reduce critical rpm of transverse and torsional vibrations
there can be sub-harmonic effects ie effects at sub-multiples of rpm in various modes stimulating actions and interactions

hot rodders ? - in classes where cams are mandated and checked eg to limits of standard street cam (or permitted modification) ....
people have added 'unbalance weights' positioned/tuned to throw the camshaft into (transverse ?) resonance around peak rpm
producing when running an increased/extended valve motion that does not appear in static checking
a legal subversion of the rules

also remember (Mr Duckworth said) eg DFV valve motion produces vibration comparable to vibration from piston etc motion

[Wazari]

@joseki - I do know Honda has a chassis dyno placed inside a wind tunnel. I do not know if the climate can be adjusted in the wind tunnel. I do not know for sure if the MP4 with the Honda PU has been tested in there but I would imagine it has. BTW is your user name the Japanese meaning for joseki? If it is, I like it.

@Tommy Cookers - I was just trying to poke fun at the people who intentionally place IMO radical camshaft profiles in street driven cars so that can have that "lump-lump vibration/resonance, when in most cases we are trying to eliminate unwanted vibrations. Maybe the term "hot rodders" was a poor choice. Obviously my attempt to add some levity was not successful

[GoranF1]

I've read somewhere that in their early development of split TC Mercedes has big problems whit the shaft vibration that conects turbo and compressor so maybe Honda had simillar problem but due to regulation restrictions they couldnt fix it in-season.?

[PlatinumZealot]

A theory that I have had in my brain (and I'm sure other people have thought of it too) that may be causing Honda problems is vibration. I'm not talking about vibration that most people are thinking of, I'm talking about resonance. Devices on a spinning shaft can be particularly susceptible to this. I'm wondering if at the top of the rpm range for the turbocharger/MGU-H it is running into resonance problems.

While this probably is not the cause as it should have been something caught in dyno testing, it did get me thinking. Then again dyno testing wasn't with the PU bolted into the car so that can change the resonance frequency of a part. The only reason that I am even thinking this may be an issue is because it seems to fit what has been said about vibration problems and connections constantly coming loose and seals rupturing.

A real world example of this phenomenon that I deal with is on the turbine engines in our helicopters. They have two shafts in them. One of the shafts is for the gas producer section (axial and centrifugal compressor, combustion chamber and first stage turbine) and the second shaft has the power (turbine that takes drive to the gearbox and rotor system). Neither shaft is mechanically linked together at all yet each shaft has its own rpm avoid range that we are not to stay in. When advancing the engine you advance it through this range quickly and smoothly and we have been warned not to stay there as the resonant frequencies that build up can destroy and engine.

Resonance like the Tacoma Narrows Bridge?

Yes I guess you can say so. I am by no means a vibration expert or even anything close so I could have been using the completely wrong word. I do however know that spinning shafts tend to end up with a rpm range that should be avoided for any extended period of time as it can damage bearings and other things.

Thinking again I'm not even sure if resonance is the right word as from what I've read generally something has to stay at the resonance frequency for a little while for the vibrations to build up.

For those more knowledgable than me, would the turbocharger/MGU-H shaft speed be changing to much for this to be a problem?

Yes. You know what though; Mercedes shaft is in a lot more trouble than Honda's. The increase in length is the real enemy when it comes to shaft critical speeds. Mercedes would have to use multiple bearings along the length of the shaft to mitigate against it. A small increase in rpm is nothing compared to doubling the length of a shaft... And the imbalances in the shaft are not as dangerous as the resonance. You can get away with a little imbalance but that imbalance loads are small compared to the resonance loads.

[Andres125sx]

@joseki - I do know Honda has a chassis dyno placed inside a wind tunnel. I do not know if the climate can be adjusted in the wind tunnel. I do not know for sure if the MP4 with the Honda PU has been tested in there but I would imagine it has.

Correct me if I´m wrong, but I think that would be ilegal as no 1:1 models are allowed for wind tunnel testing.

I think they can test the PU inside a real car, but not inside a wind tunnel, or the PU on a dynno inside the wind tunnel, but not inside the real car

[Thunder]

They can run the Cars without Wings, just like Toro Rosso did at the beginning of the Season at AVL in Austria to get Renault up to Speed.

[PlatinumZealot]

They have already correlated the car to the engine dyno. The simulated atmosphere in the car is already there on the dyno. They change the ambient temperature and the coolant temperature to simulate what the engine feels on the track. They also do whatever they can to simulate any specific problems. It is not perfect but it is what they can do.