Idea for V6 turbo configuration

[aleks_ader]

The initial idea you proposed was used in F1 in the past turbo era by Ferrari among other teams.

And this is maybe worth to try! So we will get a EBFD (exhaust blowing f duct)

[Onch]

...
Perhaps the ultimate configuration would be to have primary turbine located at the end of the engine, just above the clutch with the axle along the bottom of V (within the engine block), while the compressor would be at the front end of the engine.
...

Unfortunately I do not think the shaft linking compressor and turbine can be made stiff and dynamically balanced enough to run at x00.000rpm for more than a couple of seconds before exploding. .

Plus you'd have to design some axial and radial freedom in as the block will vibrate, expand under load, twist and bend in the corners etc.

By the time you have designed a shaft that can handle all these parameters the inertia will have increased so much that the turbocharger will not be practically usable.

[manchild]

Could shaft be replaced with steel or if possible Kevlar wire rope? I'm thinking on something similar to flexible drill shaft, only without any covering/tubing since it limits the RPM.

[Onch]

I am no Dremel expert , but I believe the external tubing is what allows the torque from the motor to be transmitted to the tool. Without it the flexible drive would just twist and bend and no power would ever reach the tool.

So I do not think this would work either.
You could think of putting the wire under a lot of tension (like a guitar string) to try and avoid bending resonances, but it would still be very weak torsionally, which would then be a problem during speed transients of the turbocharger.

[ringo]

Torsion is wasted energy. A solid shaft is best.
Though i don't really like the idea of having such a long shaft being twisted to transfer power.
The weight/inertia of that shaft will make the turbo harder to come up to speed.
Compare it's inertia to a typical turbo shaft which is probably 1/50th the weight.

[Terrible3]

The weight/inertia of that shaft will make the turbo harder to come up to speed.

My first thought. That said the weight of the shaft is positioned very close to the centre line thus its moment will be pretty small compared to the turbines.I think the inter cooler is a bigger issue as the intake charge temp will not be very equalized (perhaps my poor understanding of the drawing).

[FW17]

Alfa's V8 for CART

[xpensive]

Amazing, Alfa's CART-engine looks a whole lot better that their F1 turbos, that installation is probably very close to what we will see in 2014, little need for an intercooler with such a low boost I think. Xcept for the turbine-shaft angle of course, wonder why that rule came about to begin with?

[ringo]

Hmm, cam driven twin water pumps.

Anyway i think F1 will use intercoolers, it's a no brainer. We've discussed this in the 2013 engine thread.

[xpensive]

...
Anyway i think F1 will use intercoolers, it's a no brainer. We've discussed this in the 2013 engine thread.

Indeed we did, but that doesn't make an intercooler a "no-brainer" at 0.7 Bar, running without will have other advantages,
packaging- as well as aerodynamic-wise I would think.

[mep]

True especially with that strange fuel flow limit in mind.

[wuzak]

...
Perhaps the ultimate configuration would be to have primary turbine located at the end of the engine, just above the clutch with the axle along the bottom of V (within the engine block), while the compressor would be at the front end of the engine.
...

Unfortunately I do not think the shaft linking compressor and turbine can be made stiff and dynamically balanced enough to run at x00.000rpm for more than a couple of seconds before exploding. .

Plus you'd have to design some axial and radial freedom in as the block will vibrate, expand under load, twist and bend in the corners etc.

By the time you have designed a shaft that can handle all these parameters the inertia will have increased so much that the turbocharger will not be practically usable.

I don't think a shaft of that length, transmitting the amount of power it needs to is such a problem.

After all early Rolls-Royce Griffons used a torsionally flexible shaft that ran from the front of the engine to the rear of the engine to drive the supercharger. It would have been the best part of 2m long, and transmitting somewhat more power than this one would be required to. And they were running slower, so had to deal with more torque.

Napier Sabres also used torsionally flexible shafts to drive the supercharger. In that case the pair of shafts ran inside the shafts that drove the sleeve valves.

Axial displacement is also not so much an issue, IMO. A simple splined joint should work fine.

Remember that the turbo shaft also has to drive the MGUH. This can be fitted with a clutch and gears. It would be possible, therefore, to mount the MGUH coaxially with the turbine shaft and within the vee.

The only issue with this layout is that getting air into the compressor is compromised. I would think that, providing the compressor housing is small enough, that the shaft would be shorter, and the compressor in the vee, allowing for a better inlet design.

Alternatively, If you reverse the compressor, such that the inlet is between the compressor and the turbine, you could havnge the MGUH off the front.

[wuzak]

But they are allowed AFAIK.

Thanks. If this is true I´m surprised they didn´t shut tis door. I´m no expert in this engine stuff, but can imagine that there is some room for improvements.

Axial compressors stall easie...

correct, but as you mentioned that is because of a design point. Its all a question of number of blades, airfoils etc. etc. So maybe its possible to develope a axial compressor with better performance.

Both axial flow compressors and turbines are allowed.

However, the rules specify a single stage compressor and single stage turbine.

Axial flow compressors work best with multiple stages, especially with higher pressure ratios required. If 1.0 bar is the maximum required then a pressure ratio of 2 would be required - not sure if that could be done with a single stage.

I think an axial flow turbine could work. Not sure if it would be able to extract as much energy as a radial turbine though.

[brainscott]

So BMW finally come clean and patent their V6 turbo configuration.

I wonder where that idea appeared from and who here suggested it in the first place. I rest my case.

[allstaruk08]

So BMW finally come clean and patent their V6 turbo configuration.

I wonder where that idea appeared from and who here suggested it in the first place. I rest my case.

isn't the patent for a BMW bi-turbo v6 for the M3?