Oil temp threshhold for engine breakage? (Mainly Merlin engines)

[bongodriver]

Originally Posted by Crumpp

JtD,

It is a basic principle of heat exchanger efficiency. It is not really open to much discussion and the fact so much is made of such a simple thing is telling.



Bongodriver, by all means post your findings. You might learn something.

Take a guess what the p is in the formula??

Don't let that stop you from posting the findings from a turbojet. We can then change the subject to some basic properties of thrust producers! Like I said, you will learn something!

Learn something from you?......I doubt it.

I'm not posting pics for means of making revelations other than gratuitous 'look at me here at FL400 taking pics for my forum buddies', I couldn't post yesterday because I didn't make it back to home base before they closed and diverted to Luton, hotel had crappy wifi and I only had my phone, still it meant I got to take some more pics of todays sectors to Stuttgart and Sion, the latter being very Christmassy so I thought they'd go nice.

pics 1,2 on way back from Aalborg yesterday, pic 3,4 on ramp at Luton this morning, pic 5 on ramp at Stuttgart.

[bongodriver]

Heres the Christmassy ones, the amazing view approaching the Swiss Alps and the descent on the 'IGS' approach to Sion.

Merry Christmas everyone, maybe we'll be nicer to each other next year....

[fruitbat]

Nice photos, particularly like the first 2

what height were you over the alps?

[bongodriver]

probably around 23000' in a descent to 17000' by the time I started taking the Sion pics.

[Al Schlageter]

Nice to see a commercial pilot that actually puts his commercial license to use.

[Crumpp]

es. I totally agree with that, heat exchanger physics explain heat exchange.
Today 10:43 AM

Good, then what the heck is all the other nonsense about it does not apply to certain airplanes under certain conditions!!?

Learn something from you?......I doubt it.

I thought you were going to post some pictures on the temperatures differences for us. I see you backed off that one.

[Al Schlageter]

When are you going to list the 16 squadrons that were the only squadrons to use 100 octane fuel during the BoB?

Must be like the Fw190s that were at Stalingrad in the late fall of 1942.

[NZtyphoon]

Originally Posted by JtD

It's not a Crumpp problem here.

[JtD]

Originally Posted by Crumpp

Good, then what the heck is all the other nonsense about it does not apply to certain airplanes under certain conditions!!?

Never said that. Physics always apply. I said:
- basic principles of heat exchangers don't fully explain general aircraft engine oil temperatures
- general aircraft engine oil temperature characteristics don't fully explain Spitfire specific oil temperatures

That means, while it is comparatively easy to estimate the heat exchange in the radiator for a given set of conditions, this is just one piece of the puzzle of oil temperature calculation.

[Igo kyu]

Did they know about the counterflow multiplier in WW2?

http://en.wikipedia.org/wiki/Countercurrent_exchange

It makes a huge difference to efficiency.

In a 1951 lecture along with his student V.B. Hargitay, he was the first to hypothesize the countercurrent multiplier mechanism in the mammalian kidney, later to be discovered in many other similar biological systems.

http://en.wikipedia.org/wiki/Werner_Kuhn

So, perhaps not?