I'll have to read the link. The thing engineers worry about (especially
nuclear plant engineers at pressurized water reactor plants because their
systems are designed to operate without boiling the coolant--same as a car
only bigger) is actually "departure from nucleate boiling" which is the
transition to bulk boiling. Bad for cars and nuke plants because the steam
shrouds the heat transfer surface and dramatically reduces the heat
exchange. Compared to flow considerations (which until I read the article
I will still regard as small) lower static and dynamic pressure in the
engine will have a huge effect. The seven pounds from the radiator cap
gets added to five to 15 pounds from the water pump if it's exit from the
block is reasonably restricted to keep the bubbles small.
The easiest way to put the cap where you want it is to add an expansion
tank, then you can keep the radiator and cooling system full. If you have
a return line plumbed to the cooling system high point it will be
self-venting. Peyote has a simple tank, made from a section of large
diameter tubing. You can get a pretty aluminum one from Pegasus.
-----Original Message-----
From: WEmery7451@aol.com [mailto:WEmery7451@aol.com]
Sent: Monday, March 03, 2003 7:16 AM
To: Bill Babcock; fot@autox.team.net
Subject: Re: Head Cooling Problems
In a message dated 3/2/03 5:14:12 PM Pacific Standard Time, BillB@bnj.com
writes:
<< It's probably more about the reduced pressure allowing bubbles to
form--something engineers call nucleate boiling. I don't know about this
"water moving too fast through the radiator" notion. Usually rapid flow is
good for cooling because it keeps the boundary layer thin. >>
I agree that probably ninety percent of the engine overheating problems
result in the coolant flashing to vapor due to the loss of block pressure.
We were doing some NRC smokescreen calculations directed at optimum flow
rates in heat exchangers, trying to avert massive expenditures in plant
modifications at the Happy Valley Nuclear Plants. We also had Kas slowing
down coolant flow using larger pulleys.
The talk of the times (60s), when many TR-3 drivers would show up at
Nelson
Ledges, would be optimum flow rate and restrictor washer size. I remember
when ten to fifteen TR-3 would start a race, and we were all having
similar
problems. I seem to now be the last of them. This isn't to say that
everyone couldn't have been wrong at that time. I am now taking Randall's
"Stewart Components" seminar.
Next questions for the cross flow radiator experts:
1) I assume that I could go to a radiator shop and have a cross flow core
installed that will fit in the existing TR-3 radiator space.
2) How do you plumb the thing to put the radiator cap on the suction side
of
the system (from seminar)? This might not be possible with the tractor
blocks.
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