The analogy does not work for a closed loop system.
It's been awhile for thermals, but in the heat loss equation Q=(W)(cp)(DeltaT), where Q=energy,W=flow, cp=specific heat,Delta T=inlet-exit water temp, you can see that energy removal is proportional to flow. Obvoiusly the flows must be within reason or you get other factors such as friction losses that come into play.
If you make the water flow high and the Delta T low you maximize the heat transfer. And yes if you reduce the flow the exit water will be much cooler than the inlet temperature but heat removal from the system will be at it's lowest. Increase the flow and you maximize cooling, thus reducing the overall temperature more than if you reduced the flow.
Would you put a low flow pump to maxmize the time the water is in the radiator? No. This is why they make high flow water pumps.:biggrin:
Thanks
No, I wouldnt run a slower water pump, because then the flow would decrease in the whole system, and the coolant in the motor would have more time to heat, negating the whole thing. You want normal water flow and speed through the motor, but more time through the radiator. No matter what radiator you run, the water speed through the motor will be the same. But the flow velocity through the radiator will be different.
And you can only make the Delta T so low with our radiators and fans.
At the trailing end of the radiator, yes, transfer will be at its lowest...thats to be expected, but, as you said "yes if you reduce the flow the exit water will be much cooler than the inlet temperature"....thats the bottom line. An inefficient radiator with cooler discharge temps is better than an efficient one, with balanced heat transfer across the whole face, which produces hotter discharge temps.
And are you sure about that equation? There isnt one equation for the whole system. There is radiation, convection and conduction all at once. You mention increasing flow....is that flow velocity or mass flow? Flow velocity of the coolant isnt going to increase cooling if you have enough fin area and airflow. You speed it up and it will reduce time and reduce total heat transfer. You figure that if you move the coolant through the radiator too slow, the fins will heat up and lose most of their cooling potential, right? Not with enough fin area and airflow they wont.
This reminds me of all the proponents out there of water injection. They all tell everyone how water can draw far more heat out than alky or methanol. But water takes more time, which we dont have. If somehow, you could give the water more time, it WOULD draw out more heat, until the atomized droplets condensed and the surface area of the sum of droplets decreases.
A multi-core radiator will increase fluid flow velocity, which prevents scale and deposit buildup on the inner walls of the tubes, which destroys heat transfer. Its also distributes the heat transfer more evenly across the radiator. Once the inside of those tubes start to build up scale and other deposits, its all over with. The single row F-Body is a GREAT cooler, but if you dont have a spotless clean coolant system with distilled water only, it wont last as long as the multi core unit.
Tell me this: I had a clean core, multi core, original GN radiator. The F-Body single core cools so much better its unreal. I used to overheat everywhere, in any condition that brought about higher temps...summer, traffic, climbing up mountain roads....
The F-body with its inferior single core, lets the motor run no higher than 168 in california summer traffic, just sitting there, not moving for 15 minutes at a time, with a single stock factory fan running on low speed. In the cooler months, I can drive 35 miles to work, or home from work, without the fan even coming on!
