Oil as fuel

[R_GoWin]

1) Name a chemical that would make a good fuel AND work as a lubricant? The latest lubricants have very high combustion temperatures. As an example they can make it through a CAT without lighting off.

2) Current lubricants provide a big reduction in friction…increase in power. It is going to take a lot of combustion energy to make-up for any loss friction reduction from an inferior lubricant. In other words this is a compromise.

...

Lube oil is perfect for this, especially in an engine designed for thermal efficiencies with high compression ratio. Lube oil measures high on the Centane number scale and hence has a short ignition delay. So, <speculation starts> if the combustion precess is ultra lean - then spraying lube oil into the combustion chamber before the spark timing, will autoignite via compression ignition and act as multiple ignition source - much in the same way as TJI intends to be. Hence lube oil can be used as an ignition fuel. </speculation ends>

The devil is in the detail and implementation of the technology. I can see holes in my argument as to why they may want to do this or how its done. For example: oil has to be sprayed at a particular time and cannot be inducted from ports - otherwise how will you control when it auto-ignites? Will only lead to pre-ignition. How to spray without using a second injector?

Ofcourse - it could be used in an entirely different way, but to answer the question asked by hardingfv32 - engine oil can has good lubrication property and can be burnt via compression ignition. The underlying physics makes a case for it.

[godlameroso]

Reactivity controlled combustion!

http://gasturbinespower.asmedigitalcoll ... id=1430081

[hurril]

Reactivity controlled combustion!

http://gasturbinespower.asmedigitalcoll ... id=1430081

How would they do it though?

[hardingfv32]

Lube oil is perfect for this, especially in an engine designed for thermal efficiencies with high compression ratio. Lube oil measures high on the Centane number scale

What type of lubricant base stock are you talking about?

It was always the case in the past that the older traditional oil base stocks caused detonation when found in the combustion chamber. What is your source of your Centane number claim? I can not say that I have ever seen Centane data related to lubricants.

Brian

[godlameroso]

Control the amount of oil entering the chamber, or use the same fuel, but injected at different temperatures. You can do a lot with one very sophisticated injector. This technology works with gasoline as well, as long as the fuels have different reactivity it can be made to work, in his research Reitz used a regular gasoline, the PFI used a cetane improver, while the direct injected fuel was common off the shelf gasoline.

[R_GoWin]

Lube oil is perfect for this, especially in an engine designed for thermal efficiencies with high compression ratio. Lube oil measures high on the Centane number scale

What type of lubricant base stock are you talking about?

It was always the case in the past that the older traditional oil base stocks caused detonation when found in the combustion chamber. What is your source of your Centane number claim? I can not say that I have ever seen Centane data related to lubricants.

Brian

Hi Brian - regarding oil's cetane number, I know this anecdotally, I wouldn't be able to pin down a reference - but I'm pretty sure of it. I work in combustion and it's common knowledge. But even extending your experience with detonation of certain oil base stocks - the poor anti knock properties would imply a low octane rating (and hence high on cetane scale no?)

[Powerslide]

on hind site maybe best we also note that the amount of oil being used has to be very small but discussions seems to head towards formula that needs another large tank which is not the case. not a chemist so best i know would be a concept from 2 stroke engine but enhanced to either produce better combustion energy and only used at peak power or detonation is reduced so more boost is allowed.

if its combustion advantages, increasing bmep, it could also be a way to go about the 100kg/hour fuel limit where teams can run more fuel as total amount of combustionable exceeds that fuel flow limit. so a reverse that maybe its not as powerful as the normal fuel being used but at low power usage, the oil ratio is high then disappear towards peak power...again saving better fuel to be used later and going under the fuel flow limit

(edit, if they use it for qualifying then the theory of using it during lower power operation to go by the 100kg/hour fuel flow is void)

[dans79]

The Fia is cracking down more this year.

"However, we will expect the oil consumption of any ICE [internal combustion engine] element of the power unit introduced from the 2017 Italian GP onwards to be less than 0.9l/100km, any consumption above this will be considered suspicious and hence investigated as a potential breach of the technical regulations."

http://www.autosport.com/news/report.php/id/130890

[godlameroso]

According to the regulations you are allowed to use two different types of fuel per event, what are the chances that both fuels are being used for combustion at the same time? It's not against the rules, just tricky to get it working right.

[dans79]

According to the regulations you are allowed to use two different types of fuel per event, what are the chances that both fuels are being used for combustion at the same time? It's not against the rules, just tricky to get it working right.

They both have to meet standards, so I don't see how that would benefit anyone. Are you suggesting that when combined some kind of thermal or chemical reaction takes place to make a more powerful fuel?

[godlameroso]

When combined properly combustion is more efficient. Which is the same as more powerful in this formula so technically yes.

You are allowed some leeway as far as octane rating and some other bits, and I guess that would be the challenge. According to experiments, you would need very little supplemental fuel. 6.1.2 allows 2 liters outside of the main fuel tank, this would be more than enough.

The recent technical directive is allowing ~2.7l of oil to be burned per race. So the rule writers(manufacturers with highest political clout) are kind of hinting at this happening already.

[Jolle]

Maybe it’s been discussed here before, but diesel is not permitted? It’s got more energie per kg then gasoline. Gasoline was always the better fuel because of its fast burn rate, but with this fuel limit configuration and the turbocharging, it might work...

[Tommy Cookers]

minimum Octane Number is 75
(to keep out of F1 anything like the diesel as we know it)
there's no maximum ON

[PlatinumZealot]

Fuel is obviously more powerful than oil.. But adding more oil to the fire is still more power. We had some discussions ealier about how the teams introduce the extra 2% of oil without it registering through the flow meters. I think some folks said the oil is breathed into the engine from the oil tank. I think some of us dreamt up a secret second oil tank but that extra tank really was not necesssary since we learned the rules allowed burning of 1.2 liters of oil per 100km.

[hardingfv32]

1) But does adding oil actually make the combustion process more efficient/productive?

2) I think the context of the second tank was that a 'lubricant' was being added to the crankcase that never actually made its way into the pressurized system. The second lubricant could be added to the swirl tank where it vaporized completely and went into the vapor management system.

Brian