Oil Tank Design - seeking photos or discussion

All that has to do with the power train, gearbox, clutch, fuels and lubricants, etc. Generally the mechanical side of Formula One.
User avatar
ringo
225
Joined: 29 Mar 2009, 10:57

Re: Oil Tank Design - seeking photos or discussion

Post

flynfrog wrote:
ringo wrote:
Edis wrote:The main advantage of the centrifugal separator is that the oil tank can be made much smaller since most of the air/oil separation is made by the separator. From the separator there are two outputs, oil (also contains some air) and air (also contains some oil) and both are returned to the tank. The air return is generally returned to a higher, different position in the tank. In F1 the air from the dry sump system is returned to the engine airbox.

There are some good pictures of the tank, separator and dry sump pump of a Cosworth F1 (CR3L) engine at Gurneyflap. Do however note that this engine uses external lobe (roots) type scavenge pumps which is quite uncommon for a F1 engine these days, most F1 engines use gerotor pumps for the scavenge stages built into the lower crankcase (typically five or six stages for a V8).

http://www.gurneyflap.com/engine.html
And do you have examples of the gerotor pumps?
the one located in my truck

Image
I see. what's the diameter of these on the F1 cars? They seem pretty small at the side of the engine.
For Sure!!

simieski
9
Joined: 29 Jul 2011, 18:45

Re: Oil Tank Design - seeking photos or discussion

Post

The turbine works at the same pressure as the compressor.
And it reduces after that. Turbine engines are constant pressure combustion engines, so i was wondering why this air being dirty and all, wasn't simply fed back to the turbines.
Compressor discharge pressure and turbine pressure do not work at the same pressure, usually.
Ever stricter emissions and to reduce turbine blade contamination i would hazard a guess at, oil etc on the blades has the potential to creat local hotspots. Anything that would cause excessive build up of carbon etc on the blades is bad, their cooling and energy harnessing become less efficient, so more fuel is then required to maintain a given thrust.
Thank you to God for making me an Atheist - Ricky Gervais.

User avatar
ringo
225
Joined: 29 Mar 2009, 10:57

Re: Oil Tank Design - seeking photos or discussion

Post

And what's all that supposed to mean? :P
Compressor discharge pressure and turbine pressure do not work at the same pressure, usually.
Verbal gymnastics at it's best. :lol:

You never quite admit that the pressure is the same or lower in the turbine.

The turbine works at the same pressure or lower. Usually there is air compressor bleed off to the cabin or other auxiliaries, and then there are other little pressure losses along the line. But in the end is less than or equal to, not greater than.

A gas turbine doesn't have pressure increase during combustion.
That's why any discharge from the compressor can be sent into turbine blades for blade cooling. The compressor pressure is higher.
For Sure!!

riff_raff
132
Joined: 24 Dec 2004, 10:18

Re: Oil Tank Design - seeking photos or discussion

Post

ringo wrote:why wasn't this air sent to the turbine stage?
ringo,

The shaft seals used in turbine engines, for both compressor and turbine spools, are labyrinth seals. They function based on the positive pressure differential between the working gas and the bearing chamber. In order to return the scavenged air from the seal leakage back into the turbine flow, the scavenge air would need to be compressed to a pressure above the ambient turbine stage pressure. The net gain in turbine work would not be worth the effort. Also, if there were any lube oil left in the airflow, it would combust and likely cause thermal overloads on the turbine blades and nozzles.

However, the basic premise of your comment is correct. Any leakage/loss of the working gases is detrimental to engine efficiency. Whether it is leakage past shaft seals, around blade tips, or compressor bleed air used for turbine nozzle cooling.

riff_raff
"Q: How do you make a small fortune in racing?
A: Start with a large one!"

Edis
59
Joined: 31 Jan 2010, 16:58

Re: Oil Tank Design - seeking photos or discussion

Post

ringo wrote:I see. what's the diameter of these on the F1 cars? They seem pretty small at the side of the engine.
You can see them in this picture of the Toyota RVX09. Their diameter is small enough to make them fit in the lower crankcase casting.

Image

simieski
9
Joined: 29 Jul 2011, 18:45

Re: Oil Tank Design - seeking photos or discussion

Post

Ringo, I was mainly trying to answer your question about why the air, once the oil was seperated was not sent to the turbine module, however I also noticed you said the turbine and compressor work at the same pressure which I pointed out as being generally incorrect. Which in your next post you also seem to agree was incorrect when you definitively state 'the compressor pressure is higher.' So I appreciate you correcting yourself anyway =D>

Glad you like the use of my vocabulary, i say usually as I'm sure it can occur during abnormal events i.e stall or surge conditions.
Thank you to God for making me an Atheist - Ricky Gervais.