h a l f b a k e r y
Think of it as a spell checker that insults you, as well.

meta:

account: browse anonymously, or get an account and write.

 user: pass:
register,

# Multi-Turbine Turbochargers

They each would have one turbine per engine cylinder.
 (+6) [vote for, against]

This is basically an extra-long turbocharger with multiple turbines. I know you might be thinking that this would have more rotational mass to spin which would cause lag, but that isn't necessarily true. The entire unit would of course weigh more than a normal turbo (which wouldn't really effect anything), but the turbines could be made smaller or lighter or with less mass since each turbine would only be exposed to the heat once every fourth stroke of the engine. Since the shaft would be a lot longer it would obviously weigh more, but that doesn't matter very much because its mass is very long and narrow in the rotational direction.

I don't know if making the turbines smaller would restrict the exhaust more, or if since they would be smaller they would probably have a smaller diameter torque arm, which would potentially be harder to turn but theoretically would have a higher maximum rotational speed.

If those effects exist, one thing that might overcome them is the fact that the turbines would be much closer to the exhaust ports which means that there would be a greater force applied to the turbines but still only for every fourth stroke, also there is practically no exhaust plumbing before the turbines where the exhaust pressure can move around and compress more before it goes through the turbine.

I think this wouldn't be as efficient as a normal turbo, but it might be able to produce more power. It also wouldn't be as cost affective.

I don't know for sure if it would have more lag or less lag than normal, but if it has less then you could put a larger compressor on it which would make more boost, and if it has more lag then you might still want a larger compressor to compensate for the lag by creating more boost, but that would obviously make the lag even worse.

You could even leave the turbines close to normal size or even the size of a larger turbo and purposefully make it a lower rpm system and add an even larger compressor, which I think would make it even less efficient but could create more power, which would make it more comparable to a supercharger.

 — BJS, Jul 19 2007

Not really the same thing at all http://www.lateral-g.org/sandlin/
[Ned_Ludd, Jul 19 2007]

Diagram of it connected to an inline-four. http://i211.photobu...am.jpg?t=1185164038
I made this diagram from a diagram I found in a Google Search, the proportions may not be accurate. [BJS, Jul 23 2007]

Twin-scroll turbocharger https://youtu.be/T7JTRRlSEYI
Similar idea, with what ammounts to two turbines in the same housing. [discontinuuity, Oct 03 2016]

 This idea was originally posted as one very large paragraph.

Oh yea, If it is a V8 engine or something similar then there would be two of these units, and if its a one cylinder engine then I guess it would be just like a normal turbocharger.
 — BJS, Jul 19 2007

 You spent the entire annoyingly long paragraph explaining the benefits and drawbacks of your idea, and failed to explain what your idea was. (except for one sentence at the beginning, which is vague and does not seem to account for the myriad qualities you are describing.)

 Come back after rewriting.

[edit: neutral vote, I'm not the autoboner]
 — 5th Earth, Jul 19 2007

 Ok, I split it into multiple paragraphs and changed a few words.

I don't know how you think that I failed to explain what my idea is.
 — BJS, Jul 19 2007

 This is much like what went through my thoughts when I first heard of the "Inciner8or" '57 Chevy (link), before I saw the photos. The common-shaft idea would make for a cleaner installation, I think.

[+], therefore, for the great-minds thing.
 — Ned_Ludd, Jul 19 2007

 The most significant downside I see is that, between exhaust pulses, each turbine has three strokes in which it is not being fed any fluid under pressure, and winds up trying to suck a vacuum between itself and the exhaust valve. While that should make for some pretty extreme cylinder scavenging, I suspect that ultimately turbocharger performance will be sharply reduced.

 It'd be cool to see, though: a row of turbine housings alongside the block, forming the uppermost part of the exhaust manifold, running to big, burly impeller housing at the bow. Regardless of whether it worked well, it would certainly be impressive to look at.

Taking the scavenging effect into consideration, this may be better implemented on a port-exhausted multi-cylinder direct injection two-stroke. That would also reduce by two-thirds the dwell time in which the turbine is receiving no impulse from the cylinder, so there would be less coast-down.
 — elhigh, Jul 19 2007

What, no proposal for generating electricity via the turbines? Am I on the wrong website?
 — Noexit, Jul 19 2007

Well, for example, I fail to see what part of a multi-turbine turbo involves the turbines being placed closer to the exhaust ports. Evidently you have some clever ideas about exhaust routing that are definitely not explained in the idea.
 — 5th Earth, Jul 20 2007

for one that is pretty good. but y have them all on the same axle . have smaller individual one like in the link. small but light so it would be able to spin at a higher rate. and if you combine all the boost then it would total more than one huge one. but it would be much more costly and not alot of clearence. especially for somthing like a 4 cylinder. if you have a v8 stick with the superchargers.
 — #1gknus, Jul 20 2007

 Hmm... I get the gist of this but some kind of illustration would be great if you have the time.

 It might require one hell of a lubrication system, but certainly this would mark the next level of street racing and drag racing engines. I imagine this on an inline-6 with large exhaust ports, a huge blow-off valve, and a deep-sounding ricer muffler with about a 4" tip. [+]

Oh, and variable geometry/vane technology is your friend when it comes to less lag.
 — acurafan07, Jul 20 2007

 I bet this idea would work much better on a Wankel engine, since their exhaust output is much more even and often.

Are the 8 turbos on "The Inciner8or" really better than two, since each 4 cylinder's exhausts connect into one pipe and then are split back into four pipes to connect to the 4 turbos?
 — BJS, Jul 22 2007

The Inciner8or installation is tube sculpture, mainly. The amazing thing about it is that the engine actually runs...
 — Ned_Ludd, Jul 23 2007

 In my view using a turbine per cylinder would be over-complicated with little or no advantage. But it does make me think of an idea I had with two turbines on a single turbo. Think of a normal turbo with an extra exhaust housing & wheel attached to the same shaft. The exhaust would flow through the 1st large turbine as normal. Attached to the outlet would be the inlet of the 2nd (small, fast spooling) turbine, with a wastegate in between. When the 2nd turbine reached its peak capacity the wastegate would open to allow the 1st turbine to flow normally. You would possible need another turbo core in between the two turbines, but I reckon it could work ok.

My orignal idea was to compound two turbo's by routing the outlet from the large one into a smaller one. Then the small turbo's compressor could flow directly into the manifold while the large turbo's compressor would flow through the intercooler as normal. This way you could get incredibly fast spool (without the pressure drop from the intercooler) from the small turbo, and a great top end with the biggy. Only downfall is there would have to be one or two valves to switch the intakes. I've thought of various ways to do it. Of course there is the option of just driving the small turbo in to the inlet of the big turbo, but you'd still need a valve on that inlet to allow the big turbo to fly.
 — bytmee, Dec 01 2007

 [annotate]

back: main index