Quote:
Originally Posted by Squeetard exactly. Better flow does not equal better cooling. Coolant needs to spend some time in contact with the heat to absorb it. When we removed the thermostat from our race car we had overheating problems until we put a restrictor in place of it. |
I have to disagree on the "time contact to absorb heat." Perhaps this is an isolated case due to excessive flow creating mini-eddies through the cooling system.
IIRC. Heat is the excitement of atoms in a material. Major factors of cooling are thermal conductivity of the medium, surface area of dissipation, and Delta T. As water rushes by cooling matrices, the water molecules have higher entropy (in layman's terms, it'll bump against the heated material more often, therefore increasing the rate of energy transfer). A higher flow will allow the loop to transport those energized water molecules to the radiator where the heat will be dissipated via the reverse process.
Slower rate of flow will hinder the rate of which water can dissipate the heat carried. Therefore, increasing the average temperature of the water, therefore decreasing cooling potential by having a smaller Delta T.
Worst case scenario, water will go under high turbulence when met with the cooling matrix (such as the case for a badly designed waterblock). Where the water will be recycled through eddies, and cooling potential decreased dramatically.
/rant