Hey, I was just talking about more spare time at work! Doing a CFD analysis
of a radiator would "look" like real work to my colleagues/boss, while
actually doing something more interesting to me!
Spare time away from work right now would be concentrated on sorting my
brakes...
Good point on the turbulent flow from James, that makes perfect sense to me.
However, I have my doubts about his colleagues theory. Agreed, if you
increase coolant flow throught the radiator without increasing air flow then
you may not increase your rejected heat much. But I can't see it actually
making things worse. Things can only get worse if less heat is transferred
from the radiator to the air; I can't see how increasing the coolant flow
could result in the air taking less heat than for slow coolant, for a fixed
air flow rate. If anything it will take slightly more, since the coolant
will drop in temperature less during its journey through the radiator, so
near the outlet the coolant will be hotter, so a larger temperature
difference between the coolant and the air, so a bit more heat rejection.
James' colleagues arguement that you will remove more heat from the engine
with increased flow is not necessarily true once the system has settled down
to a balanced condition - although flow is higher, so there is more coolant
to carry heat out of the engine, the temperature rise of the coolant through
the engine will be lower as it has less time to heat up, so since heat taken
out of the engine equals coolant flow rate x temperature rise (x specific
heat capacity) the rate of heat removal could stay the same.
We could go on like this forever...
Richard & Nancy (with dodgy brakes, so not on the road quite as soon as I
hoped)
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