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Old 10-21-2013, 10:08 PM   #54 (permalink)
mort
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Quote:
Originally Posted by Occasionally6 View Post
If you can't find any you are not looking. Every discussion of the flow across an exhaust valve covers sonic flow on blow down.
Hi Occasionally6,
I've been watching this discussion, it looks like a fine example of the Dunning–Kruger effect.

But to help out - this:
Internal Combustion Engine Fundamentals by John Heywood, page 225 in my copy. He even mentions choked flow for intake valves!
But here are two excerpts, one from chapter 6 Gas Exchange Processes



and the other from appendix C.



Everybody knows this, so I thought a discussion of it being just theoretical was amazing.
Now Heywood never says supersonic, or even sonic, he says "velocity of sound" or sometime Mach = 1. In my experience, and probably yours too, when an engineer says "supersonic" they mean speed of sound or higher. Only pedants say sonic - sorry, I see you just did.

-mort
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