2014-2020 Formula One 1.6l V6 turbo engine formula

[dren]

We should hear the post exhaust port ignition pre turbine if it's taking place, right?

[gruntguru]

..... The extreme case where some cylinders are permanently inactive is fascinating. If say 3 cylinders were inactive, they could be designed for lower friction, lower temperatures, valves sized and timed to minimize pumping loss (intake and exhaust on every stroke?). Boost would be much higher to burn the same fuel in a 800cc 3 cyl. Charge air cooling could be applied for the three active cylinders only. The charge for inactive cylinders could be heated using waste heat from the post-turbine exhaust. Inactive cylinders could feature in-cylinder expansion to recover some turbine energy direct to the crankshaft (circumventing the 120kW MGUK limit.)

the inactive engine ......
does this have 6 bar boost ? - or eg 3 bar ? - or lower ?
what is the CR ? - eg maximal or minimal (incidental as an artifact of displacement) ?
when/how is the heat added ? - in-cylinder via a heat exchanger ? - or in cylinder by exhaust recirculation (addition) ?
the heat should be added after compression ?
what can its net output be ? if any ?

Inactive engine would have same boost as active. (only one compressor and throttling to produce a lower boost for the inactive half is very inefficient. Besides you want the highest boost available to run the inactive as an air-motor)
I was thinking heat would be added after the compressor and prior to the cylinders.
Strange valve timing would be required to expand the air admitted at MAP to the (assumed lower) exhaust back pressure. Alternatively the inactive cylinders could expand air to atmospheric and exit via a "wastegate".

btw - if we supplied a rich mixture to the active there would be ......
continuous combustion (of fuel carried over) ahead of the turbine (if the active's and inactive's exhausts were combined there)
or combustion in the inactive cylinders if the active's exhaust was combined with the inactive's gasflow there
and the active would need far less than 6 bar boost, so improving turbine recovery and reducing friction losses etc
what's not to like ??

Of course combustion in the exhaust is a very inefficient use of fuel. Heat produced by in-cylinder combustion can be expanded much further - in the cylinder and in the turbine.

[Tommy Cookers]

ok, I can see that 80% compressor efficiency at a PR around 6 has credibility ......
http://link.springer.com/article/10.100 ... 2-x#page-1

Edit fwiw .......
80% isentropic steady state efficiency might imply 78% typical 'best real' efficiency in F1 (allowing for matching and entropy effects etc)
the turbine would be more efficient than the compressor - maybe 82%
so imo the case for such high AFR (with a single stage simple compressor and turbine as mandated) is not established

can we expect higher compressor and turbine efficiencies than above at the 2 - 3 bar PR expected with 6 active cylinders ?

and is the stratified charge approach to such high AFR less favourable wrt entropy than the hypothetical equivalent homogeneous charge ?
the conceptual insulation benefit being somewhat impaired thermodynamically by the correspondingly higher temperature elsewhere ?

[trinidefender]

Talking about having the ICE permanently running with a reduced cyclinder count to potentially increase efficiency has got me thinking.

What about using a 5 stroke ICE where the the centre cylinder is the low pressure expansion cylinder. Shouldn't you achieve the efficiency gains through reduced surface area from limiting combustion to 4 cylinders instead of 6 and at the same time, potentially be able to take advantage of the additional expansion in the centre cyclinder that is fed by the exhaust gases of the 4 combustion cyclinders?

http://www.ilmor.co.uk/capabilities/5-stroke-engine

[3jawchuck]

Talking about having the ICE permanently running with a reduced cyclinder count to potentially increase efficiency has got me thinking.

What about using a 5 stroke ICE where the the centre cylinder is the low pressure expansion cylinder. Shouldn't you achieve the efficiency gains through reduced surface area from limiting combustion to 4 cylinders instead of 6 and at the same time, potentially be able to take advantage of the additional expansion in the centre cyclinder that is fed by the exhaust gases of the 4 combustion cyclinders?

http://www.ilmor.co.uk/capabilities/5-stroke-engine

Wouldn't that breach this rule:
5.1.1  Only  4-­‐stroke  engines  with  reciprocating  pistons  are  permitted.

And maybe to a lesser extent these rules:
5.1.2  Engine  cubic  capacity  must  be  1600cc  (+0/-­‐10cc).

5.1.7  .... All  six  cylinders  must  be  of  equal  capacity.

It is a shame that engine manufacturers aren't allowed to really go to town on the fuel restricted formula.

[trinidefender]

Talking about having the ICE permanently running with a reduced cyclinder count to potentially increase efficiency has got me thinking.

What about using a 5 stroke ICE where the the centre cylinder is the low pressure expansion cylinder. Shouldn't you achieve the efficiency gains through reduced surface area from limiting combustion to 4 cylinders instead of 6 and at the same time, potentially be able to take advantage of the additional expansion in the centre cyclinder that is fed by the exhaust gases of the 4 combustion cyclinders?

http://www.ilmor.co.uk/capabilities/5-stroke-engine

Wouldn't that breach this rule:
5.1.1  Only  4-­‐stroke  engines  with  reciprocating  pistons  are  permitted.

And maybe to a lesser extent these rules:
5.1.2  Engine  cubic  capacity  must  be  1600cc  (+0/-­‐10cc).

5.1.7  .... All  six  cylinders  must  be  of  equal  capacity.

It is a shame that engine manufacturers aren't allowed to really go to town on the fuel restricted formula.

I wasn't entirely thinking of this concept being in the current rule set, more of purely as a thought experiment. Well I guess it will contravene the first rule. As far as rule two and three all the cylinders can be of the same capacity. The Ilmor concept does have a larger centre cyclinder however I don't see why the concept can't be applied to having the same sized cyclinders with a slight efficiency penalty. Why would it contravene the 1600 cc rule? It will still be 6 cyclinders with a total of 1600 cc however the outer cylinders of the banks will be the only ones used for combustion and the centre cylinder will be the expansion cylinder.

GG, TC and others, thoughts?

[ringo]

interesting stuff:



Unrelated to the above video but this technology is in use in the marine industry by Rolls Royce, for its new LNG powered engines. They have claimed efficiencies of 50% and 20% on top of that with regeneration (combined cycle maybe).

[hurril]

I'd be more interested in seeing what could be achieved with a multi-stage compressor and/ or turbine.

[3jawchuck]

Wouldn't that breach this rule:
5.1.1  Only  4-­‐stroke  engines  with  reciprocating  pistons  are  permitted.

And maybe to a lesser extent these rules:
5.1.2  Engine  cubic  capacity  must  be  1600cc  (+0/-­‐10cc).

5.1.7  .... All  six  cylinders  must  be  of  equal  capacity.

It is a shame that engine manufacturers aren't allowed to really go to town on the fuel restricted formula.

I wasn't entirely thinking of this concept being in the current rule set, more of purely as a thought experiment. Well I guess it will contravene the first rule. As far as rule two and three all the cylinders can be of the same capacity. The Ilmor concept does have a larger centre cyclinder however I don't see why the concept can't be applied to having the same sized cyclinders with a slight efficiency penalty. Why would it contravene the 1600 cc rule? It will still be 6 cyclinders with a total of 1600 cc however the outer cylinders of the banks will be the only ones used for combustion and the centre cylinder will be the expansion cylinder.

GG, TC and others, thoughts?

Oh, no worries then.
On second thoughts you're right, it doesn't have to contravene 5.1.2 my bad there.
I'd actually love to see the engine companies being able to try vastly different concepts.

When I first heard of this concept (in a racecar engineering I believe) I thought it'd be a pretty cool project to adapt out of an old engine for fun and education, looking forward to seeing someone trying that.

[gruntguru]

Talking about having the ICE permanently running with a reduced cyclinder count to potentially increase efficiency has got me thinking.

What about using a 5 stroke ICE where the the centre cylinder is the low pressure expansion cylinder. Shouldn't you achieve the efficiency gains through reduced surface area from limiting combustion to 4 cylinders instead of 6 and at the same time, potentially be able to take advantage of the additional expansion in the centre cyclinder that is fed by the exhaust gases of the 4 combustion cylinders?

The 5 stroke concept needs approximately the same capacity of expansion cylinders (expanding once per revolution) as combustion cylinders (firing once per two revolutions) - this will double the expansion available in the firing cylinders. Using 1/3 of the cylinders for secondary expansion won't work, since they only displace the same amount as the firing cylinders. The 5 stroke concept has limited potential in a high compression turbocompounded engine.

[Tommy Cookers]

the F1 rules have been written around an engine concept having an exhaust turbine for the second expansion, not an LP cylinder
there would be little or no value in having both
(similarly the rules avoid the need for VVT or VG crank for extra expansion, and the need for anti-lag or traction control etc)


the RR Bergen turbocharged lean burn natural gas marine engine that Ringo mentioned (try NMA Norge 22 Jan 2014 - I can't get a link to post)
uses continuously a ('premixed') lean-burn 2.2x lamda AFR and so has a very high CR
SI with an initial rich core mixture of course
efficiency at high powers (without ancillaries) is up to 49% - (with further progress envisaged, by exhaust recovery ?)

so imo their engine is roughly twice the size a hypothetical 1.1x AFR engine would be (ie twice the friction and pumping losses)
((ok, such a 1.1x AFR engine would need lower CR to avoid detonation, although LNG is 'high octane')
so theirs is eg a 20 tonne 2.2x AFR 5000 hp engine giving 49% at high power and a lot less at low power (further leaning impossible)
the hypothetical 10 tonne 1.1x AFR 5000 hp engine would give 46% at the same high power and not so much less at low power (via further leaning)

but they don't make the hypothetical engine because ......
their 2.2x engine has naturally almost no NOx (the peak cycle temperature being much lower)
and there's an upcoming ban on NOx in EU waters (for EU operators) etc

which approach (with gasoline fuel of course) is better in eg F1 ? ....... and which approach is better for our road cars ?

wasn't someone saying the mandated F1 engine size (with mandated rpm and mandated car weight) is bigger than necessary for the fuel rate ?

but the lean burn 2.2x will give a bigger headline efficiency figure (so making the politicians look good)
doesn't this sound just like recent Mercedes & FIA PR ?

as I said 4 years ago, the F1 rules are commendably ingenious (but a European stich-up nevertheless)

[erikejw]

Qualy mode thought:
We all remember the exhaust blowing cornering for better downforce.

What about generating extra heat for the MGU-H during breaking or cornering?

[godlameroso]

The K already does that, it can feed power harvested from the K directly to the H, and vice versa, and it's unlimited. You just can't charge the ES more than 2 MJ via the K, that's all.

[erikejw]

My idea is to burn fuel in a non acceleration phase to generate more heat and use that as an extra energy boost during a qualy lap. More heat generates more energy from the MGU-H.

[godlameroso]

My idea is to burn fuel in a non acceleration phase to generate more heat and use that as an extra energy boost during a qualy lap. More heat generates more energy from the MGU-H.

not exactly, besides, you're trying to be efficient, I suspect they go to great lengths to use as little fuel as possible.