IF his flow rates were correct, the 2ed row would have to have a negative contribution
- added second row decreases fluid velocity by 50%, fluid spends 2X time in tube
- the shrowded second row = warmer air, less direct tube exposure; affecting 50% of the flow

so IF Joe's air flow/velocity is constant then the 1st row would replicate the Pro (assuming that halving the flow rate did not materially affect the coolant/tube heat transfer) and the second would be rather less due to the lower coolant/air temp differential; averaging the 2 streams together will result in a lower dT than the Pro alone

there is a bit more than this going on, which is why higher air flows can reverse this ratio

"its not so hard"
Winding me up aintcha

Had not thought of that. But IF this is the case, wouldn't the Pro and Extreme present rather different Heat dissipation vs coolant flow curves? (Would expect the Extreme to max out further up the GPM axis)

you have not yet seen a good dataset

why coolant flow ?
look at the other side of the tubes, the rate limiting part

"why coolant flow ?"
was thinking about this - "added second row decreases fluid velocity by 50%"

ok for the second statement (re. air side), but it's the negative contribution thing thats bugging me (slightly)

not strictly true due to the difference in dP between the two, the 'problem' is that the difference is so slight (the tubes are not the major source of head loss in a rad)
were the second row to also halve the flow resistance, resulting in appreciably higher flow, then all would be well
but it is not

I'll post the BI dP curves later or tomorrow - completing them now

try fin heat saturation

"try fin heat saturation"

Was just musing about 'heat exchanger efficiency'(?), have not found in Wolverine though. Same thing?