Temperature question

[dicer]

For verification, does the average cast iron head combustion chamber material operate at close to coolant temperature, this is liquid cooled. Has anyone done tests of the various points in a combustion chamber and in and around valve seat and port areas?
And what kind of data acquisition equipment was used? Links would be nice.

 

[patprimmer]

There is a very dynamic temperature profile going on with a large number of variables happening very quickly. The temperature gradient will be from almost chamber temperature at the surface of that part of the chamber to almost coolant temperature at the other surface.

Regards
Pat
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[dicer]

I figured that. I just wanted some verification that the cross section as a whole is not in the 400 deg F range. If it was the coolant would boil off even with 50/50 mix ethylene glycol.

And then there was I think Matsooty's (think it was him) mention of boundary layer in the combustion space as an insulator of sorts.

 

[patprimmer]

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

This is a bit verbose, but it explains what you asked.

Regards
Pat
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[dicer]

I highly doubt any engine manufacture, automotive of otherwise, would just calculate temperatures, if so no wonder there are so many problems with the vehicles nowadays. There is no way to calculate something that isn't steady state. Exhaust valve temperatures would vary with the amount of power demand and the air/fuel ratio. I'm just looking for an average combustion chamber wall temp on say an old chevy 6 or V8.

 

[IRstuff]

"There is no way to calculate something that isn't steady state"

That's done every day on lots of different problems. CFD is all about transient simulations.

TTFN

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[SomptingGuy]

Thermal analysis of the cylinder head, combustion chamber is a serious business in the auto industry. There are armies of FEA and CFD analysts optimizing coolant passages and head geometries to keep the surfaces within acceptable limits. CFD is often used to provide cycle-averaged boundary conditions for a FEA thermal solution. FITA is a thing of the past.

- Steve

 

[btrueblood]

"There is no way to calculate something that isn't steady state."

What IRstuff said. And 'way before CFD...there was ballistics. Every part of that field of study deals/dealt with things in motion.

 

[FahlinRacing]

Exhaust valve temperatures would vary with the amount of power demand and the air/fuel ratio.

Don't forget your seat width and material and valve design/material and valve guide as well.

 

[dicer]

I did react too fast and typed that. Wrong choice of words.
I wasn't even thinking computer simulations. I'm stuck in the 50's I guess.

 

[IRstuff]

The only downside of CFD and FEA is that the packages are usually quite expensive. There are, however, a number of open-source programs, but I haven't tried any of them, although I had tried, in the past, a relatively inexpensive CFD program that seemed to work tolerably well.

http://sourceforge.net/search/?q=finite+element+thermal

TTFN

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