Page 59 of 1332
Re: Honda Power Unit
Posted: 25 Apr 2015, 22:14
by denktank
Re: Honda Power Unit
Posted: 25 Apr 2015, 23:20
by Charlatan
Vortex37 wrote:Scarbs says that the key to Mercedes superiority is the layout of the turbo/MGU/compressor.
...
Which has very little to do with it. MHPE's superiority is all in the interaction between MGU-H and MGU-K, peak-power is probably about the same for all, but the ability to produce said peak power anywhere around the track is where it's at.
Re: Honda Power Unit
Posted: 26 Apr 2015, 00:35
by djos
Just wondering, if Honda did choose the axial compressor route, surely they could argue that as long as they only have a single compression chamber they are within the rules and that the multiple layers of blades is effectively a single stage as a result?
Correct me if I'm wrong here, but if you look at a modern high or low bypass jet engine, they essentially have multiple axial compression and expansion chambers aka stages.
I'm not an engineer so feel free to chop my reasoning into small easily disposable pieces.
Re: Honda Power Unit
Posted: 26 Apr 2015, 02:22
by wuzak
djos wrote:Just wondering, if Honda did choose the axial compressor route, surely they could argue that as long as they only have a single compression chamber they are within the rules and that the multiple layers of blades is effectively a single stage as a result?
No, I think that wouldn't fly.
Each of those multiple layers increases the pressure of the air.
So if each layer has a pressure ratio of 1.5:1 then they would get 1.5 through the first stage, 2.25 from the second, 3.375 for the third.
For it to be accepted as a single stage there ca't be variation in pressure between each layer of blades, which means it is pointless to have those extra layers.
djos wrote:Correct me if I'm wrong here, but if you look at a modern high or low bypass jet engine, they essentially have multiple axial compression and expansion chambers aka stages.
Yes, they do. A turbo fan will typicaly have a fan section of one or two rows, followed by a multi stage low pressure compressor and then a multistage high pressure compressor.
Driving these they will have a high pressure turbine and low pressure turbine. They also may have an intermediate pressure turbine for three shaft designs. Each of these will have a samll number of turbine stages.
It is the turbine which is the expansion section.
I wonder if you mean the stators, which separate the compressor wheels? These can simply guide the air onto the next set of blades or can provide part of the compression.
If your multiple layer compressor didn't have stators it woudl need to counter rotate alternate stages, or it likely wouldn't work very well. You would be better off in joinin those blades together to form a long single wheel.
Re: Honda Power Unit
Posted: 26 Apr 2015, 03:11
by djos
Good explanation thanks, however we have seen things like double deck diffusers get passed despite seemingly being illegal so who knows what Honda actually have.
Re: Honda Power Unit
Posted: 26 Apr 2015, 03:43
by wuzak
Things like the double diffuser and the F-duct had loopholes in the wording.
I don't see that is the case here.
Re: Honda Power Unit
Posted: 26 Apr 2015, 03:48
by J.A.W.
& Honda has yet to show any advantageous racing results from their machine - so far..
Re: Honda Power Unit
Posted: 26 Apr 2015, 03:49
by djos
wuzak wrote:Things like the double diffuser and the F-duct had loopholes in the wording.
I don't see that is the case here.
It depends on how the lawyers define "single stage" i guess, engineering will come 2nd as usual.
Re: Honda Power Unit
Posted: 26 Apr 2015, 04:06
by wuzak
djos wrote:wuzak wrote:Things like the double diffuser and the F-duct had loopholes in the wording.
I don't see that is the case here.
It depends on how the lawyers define "single stage" i guess, engineering will come 2nd as usual.
They can try!
Re: Honda Power Unit
Posted: 26 Apr 2015, 12:52
by Edis
PlatinumZealot wrote:It IS a mixed flow compressor no matter how you look at it. Even your own post suggest that it is.
You are being a bit literal but, Edis you are correct that street car compressor wheels are mixed flow. To the chagrin of some here,
I already know that the typical radial compressor is mixed flow 
(sorry guys). The thing is, the common radial compressor is not called mixed flow these days. For the masses here, I used that photo because I know that is
what he meant ( a more pronounced combination of axial then a radial).
I have worked with double sided pump rotors before... Your typical domestic booster pump is double sided. Basically two pump rotors in one if you ask me.. they also deliver high higher pressure ratios. In my post, I said it can be argued to be two compressors. One gas path going in the splits into two different gas paths then joins back again. Heck you can even put two different blade designs on either side if you want. I have no idea what would be the dynamic results of that though. But again
in my opinion dual boost can be argued to be two compressors. Why? because say, for example if you stuck two regular compressor wheels on the same shaft facing the same direction instead of back to back, by the wording of the rules it would be no different from a "dual boost" compressor. And yes it would be can be said to be a single stage too... (one step in compression). So it would be up to the FIA to clear this up...
Guys do you realize you have discovered a loop hole!
None of the stages of that compressor have a discharge that is both axial and radial, or in other words, a meridional exit angle between 0 and 90 degrees. A multistage compressor having stages with both 0 and 90 degree meridional exit angles does not make a mixed flow compressor.
Right side of figure 1, figure 4, 8 and 11 shows a mixed flow compressor.
http://turbolab.tamu.edu/proc/turboproc ... 39-147.pdf
The regular automotive turbocharger uses a radial compressor with a vaneless diffuser.
Displacement machines without internal compression are not very efficient as "compressors", and they don't match that well with turbomachines.
Re: Honda Power Unit
Posted: 26 Apr 2015, 14:17
by PhillipM
wuzak wrote:Things like the double diffuser and the F-duct had loopholes in the wording.
I don't see that is the case here.
If the stages rotate at the same speed just with differing blade profiles and pitches, then maybe you could just join them with a rotating shroud and claim that it's still one stage as it's all one single rotating assembly? Depends more on how the regs define it rather than what it's actually doing in engineering terms...
Re: Honda Power Unit
Posted: 26 Apr 2015, 14:34
by Charlatan
Edis wrote:
...
Displacement machines without internal compression are not very efficient as "compressors", and they don't match that well with turbomachines.
The point is that a vane-compressor actually has internal compression, if you carefully stydy the images, you might see that.
Said internal compression is achieved by the eccentricity between rotor and housing, just use your imagination a little bit.
Re: Honda Power Unit
Posted: 26 Apr 2015, 16:12
by shady
The cutaway of the blade profile creates smaller compression chambers similar to a traditional multistage axial. One stage?
Re: Honda Power Unit
Posted: 26 Apr 2015, 17:31
by PlatinumZealot
Edis wrote:PlatinumZealot wrote:It IS a mixed flow compressor no matter how you look at it. Even your own post suggest that it is.
You are being a bit literal but, Edis you are correct that street car compressor wheels are mixed flow. To the chagrin of some here,
I already know that the typical radial compressor is mixed flow (sorry guys). The thing is, the common radial compressor is not called mixed flow these days. For the masses here, I used that photo because I know that is
what he meant ( a more pronounced combination of axial then a radial).
I have worked with double sided pump rotors before... Your typical domestic booster pump is double sided. Basically two pump rotors in one if you ask me.. they also deliver high higher pressure ratios. In my post, I said it can be argued to be two compressors. One gas path going in the splits into two different gas paths then joins back again. Heck you can even put two different blade designs on either side if you want. I have no idea what would be the dynamic results of that though. But again
in my opinion dual boost can be argued to be two compressors. Why? because say, for example if you stuck two regular compressor wheels on the same shaft facing the same direction instead of back to back, by the wording of the rules it would be no different from a "dual boost" compressor. And yes it would be can be said to be a single stage too... (one step in compression). So it would be up to the FIA to clear this up...
Guys do you realize you have discovered a loop hole!
None of the stages of that compressor have a discharge that is both axial and radial, or in other words, a meridional exit angle between 0 and 90 degrees. A multistage compressor having stages with both 0 and 90 degree meridional exit angles does not make a mixed flow compressor.
Right side of figure 1, figure 4, 8 and 11 shows a mixed flow compressor.
http://turbolab.tamu.edu/proc/turboproc ... 39-147.pdf
The regular automotive turbocharger uses a radial compressor with a vaneless diffuser.
Displacement machines without internal compression are not very efficient as "compressors", and they don't match that well with turbomachines.
Ok. You are talking just abouy the exit of the diffusers being 90 degrees. I understand that.. However. If you look at the gas path from the inlet.. For both compressors the flow still has axial and radial components.Even on the developed mixed flow one in the paper the gas still ends up at 90 though out of the rotating part of the compressor. Very minute details. At the end of the day it to the average man the outside of hondas compressor will still look like the conventional compressor..
Re: Honda Power Unit
Posted: 26 Apr 2015, 18:07
by PlatinumZealot
Erm on the same note. In the paper edis posted. The mixed flow compressor can move more air for each rotation.
If the some engines had mixed and some conventional compressors there would definitely be a significant difference in turbine speed. You would be able to pick it up. so if someone with the equipment can do an anaysis that would be interesting