Trying to find info about ICE piston heat models.

[Topher925]

I'm looking at different topics for my masters thesis and one of them that has a lot of potential is a heat transfer model for a piston in an internal combustion engine. Apparently the auto industry has never directly addressed this problem and use a trial and error method when it comes to maximum piston surface temps. Because of this I'm having a hard time finding any info about it. Anyone know a good place to look, something I could access from my library preferably.

 

[stewartcs]

I'm looking at different topics for my masters thesis and one of them that has a lot of potential is a heat transfer model for a piston in an internal combustion engine. Apparently the auto industry has never directly addressed this problem and use a trial and error method when it comes to maximum piston surface temps. Because of this I'm having a hard time finding any info about it. Anyone know a good place to look, something I could access from my library preferably.

I'd try some online Journals. They should be accessible from your university's library.

CS

 

[brewnog]

There are certainly models in use. Sounds like a good project idea though. Suggest you do some reading, particularly in the SAE and IMechE proceedings.

 

[Topher925]

I've looked through all the online journals I have access to the ASME website and the only publishing I can find are in french or german. There seems to be some info on piston rings but not the pistons themselves. The closest thing I could find in english were papers that only had experimental results but nothing that including any type of modeling.

 

[engrfakhar]

i am too working on the same area but i have not yet found any good stuff regarding modeling. so guide in this research area, i.e. heat transfer model of Spark ignition engine piston.
Thanks in advance

 

[Ranger Mike]

this area was extensively researched in the early 1960s by the racing community. Current piston design is directly a consequence of a racers efforts to find the lightest piston combination at 13 to1 compression ration. yes it was a lot of trial and error. Detonation being the watch word here. The endeavor made many an ash tray back in the day...i.e. turned a beautiful sculpted aluminum slug into an ashtray after it collapsed, got toasted, ring lands broke, etc..

Piston cooling...this is a function of oil control which is directly related to clearances in the connecting rod bearing / crankshaft assembly.

Piston cooling - directly related to piston ring placement..

prior to a guy called Smokey Yunick ,

Detroit thought the minimum distance the top ring could be placed to the piston top ( deck) was 0.340"..any ideas on what the true minimum turned out to be??read Power Secrets by Smokey Yunick (S-A design Books).

 

[AlephZero]

Remember that for auto manufacturers, this sort of information has a lot of commercial value, so you are unlikely to find much detail (and certainly not any numbers relating to their "real" production engines) in the open literature.

If your college has some contacts with the industry, you may be able to get some information direct from the the companies, especially if you research topic is something that might be useful to them in return. You will probably have to use sanitised "generic" data in your published thesis, but at least it will be based on a real product and use realistic modeling techniques.

 

[Fahlin Racing]

Ranger Mike wrote

Detroit thought the minimum distance the top ring could be placed to the piston top ( deck) was 0.340"..any ideas on what the true minimum turned out to be??

If I had all my parts at hand I could measure at Chevy, Mopar and Ford to give a rough estimate. Forced induction pistons I believe will/could be different since the heat production is higher.

 

[Ranger Mike]

Fahlin as always you are correct..typical race engine piston deck thickness is .150 ans Smokey ran them down to .125 before it got iffy at 12 to 1 comp ration
if you run a super light weight outlaw car you can get into super lite pistons with .090 thick wrist pins and very skinny diameters knife edge crank throws etc,,
and supercharged engine will have thicker pistons but do not know details..arias, forgetrue, jahns, JE all the SEMA jobbers can supply the details. I like Arias piston as their tech guys are a real help and a wealth of application experience from monster trucks to land speed engines

 

[mender]

The rate of heat transfer into a given piston and the resulting thermal expansion is taken into account when designing the piston - alloy, ring placement, skirt shape, etc. - so I'm pretty sure this area of R&D is fairly mature.

I suspect that a reasonable shot at duplicating the piston manufacturers' efforts could be achieved with existing FEA software but I'm not up to speed on what's available. Call some of the aftermarket piston suppliers and let them know what you're doing, they might be willing to help you with an eye towards future employment.

 

[Fahlin Racing]

I broke out the old Buick V6 "How to Hot Rod" book and looked at the supposed turbo vs N/A pistons. The piston deck is .200" with the difference being in the top rings, Turbocharged top ring .0625" vs .043". Also the deck thickness at the slightly angled part (10 degree) from the center of the piston due to valve reliefs is .200" thick for N/A and .250" thick within that 10 degrees etc for forced induction. No thermal maps though.

Mike, I forgot how much tech is in Smokey's book! I had to open it back up and comb through it tonight. I have heard though, Grumpy's SBC book is pretty good too.

 

[mender]

Here's a start:
http://www.mre-books.com/sa21/sa21_5.html

 

[Ranger Mike]

Mender, Fahlin..your right i lost my book by grumpy jenkins..plus this is 20 year old tech stuff..am sure the newer metallurgy stuff is much better but your input can be a good start for Topher925

 

[mender]

I have my Grumpy book handy but haven't opened it lately; any particular part that someone wants me to check?

Published in the '70s so a bit dated; we now make the same hp/cid with less rpm and much longer engine life. 40 years of progress!

More articles:
http://www.aijstpme.kmutnb.ac.th/PDF/Vol.2%20No.4/14.pdf
http://www.vtt.fi/inf/pdf/tiedotteet/2002/T2178.pdf
http://onlinelibrary.wiley.com/doi/10.1002/ppap.200931502/pdf
http://www.rtu.ac.in/main/syllabus/Approved_syllabus%20Vth%20to%20VIII%20sem%20automobile.pdf

And a list of papers:
http://www.sae.org/search?searchfield=piston temperature analysis fea

As Brewnog suggested, lots of info at the SAE site.

 

[Fahlin Racing]

I haven't had the time to check, but, try 'The internal combustion engine in theory and practice' by Charles Fayette Taylor or something by Sir harry Ricardo. I have a book written by Robert N. Brady in mid 90s, Modern Diesel technology. Even though its 15 or so years past we still utilize direct high pressure injection fuel systems and some applications have moved from trunk pistons to oscillating 2-piece and the oppposite transitions. The thing that I have seen also is how the crowns are constructed and finished. Also take into consideration different manufacturing methods. Numerous bowl/dome configurations around.

As far as looking at just heat maps on the piston, this is assuming our in-cylinder mixtures are at stoichiometric & homogenous for the desired engine output. Its going to be different once our working fluid has entered and becomes ignited in an engine out in the elements instead of a testing room.

The tech that Yunick and Jenkins used is still usable for scootin' around on any track. I am actually pretty curious about how Smokey went about things with his Indy cars.

Reher Morrison Race Engines has a book out, not sure if the school library will have that though.

 

[Fahlin Racing]

any particular part that someone wants me to check?

Anything relating the ring package and heat of crown or similar maybe?

 

[Ranger Mike]

hey mender..pls post the complete name and publisher of grumpys book so i can order it...thanks much ..rm

 

[mender]

"The Chevrolet Racing Engine" By Bill Jenkins, S-A Designs, ISBN 0-931472-01-6.

Top ring groove was 0.060" to 0.080" down from the piston deck on a drag engine, add 0.020" for circle track or other endurance application. As usual that's only part of the equation and Grumpy does a good job of explaining his reasoning. Nothing on piston temps though; I didn't remember there being any mention so it's nice to know my memory still works occasionally.

 

[Ranger Mike]

thanks a lot mender...yes i think smoky was running pretty thin for long circle track races..one may get by with grumpys super thin ring to deck clearances on a 1/4 mile blast but not for 500 miles of hi rev racing...i got to get that book..thanks again!
rm