Radiator question, for thermodynamics/heat transfer experts |
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Radiator question, for thermodynamics/heat transfer experts |
bondo |
Feb 2 2005, 12:26 AM
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#1
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Practicing my perpendicular parking Group: Members Posts: 4,277 Joined: 19-April 03 From: Los Osos, CA Member No.: 587 Region Association: Central California |
Hopefully I can get some input on this without too much of the inevitable "that won't work" (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif)
I'm cutting down a large tall radiator into a shorter one.. 1/3 the height to be exact. The 3 layers of radiator will be set up in a cross flow, sequentially. The hottest water will enter the rearmost later, travel across, then across again in the middle layer, and across yet again in the front layer. The idea is the hottest water gets the hottest air, and the coldest water gets the coldest air. This way delta T stays pretty constant.. I'm thinking of it as trying to heat the air as much as possible, which would cool the water as much as possible. So I realize that cooling capacity will be reduced, as I will be dealing with 1/3 as much air. But then the cooling capacity must be more than 1/3, because it's 3 layers thick instead of 1. My question is what percentage of the original cooling capacity should I be expecting? Would it do me any good to do 5 layers instead of 3? (by adding 2/3 of a second radiator) The original radiator cooled the same engine just fine, in a heavier car, with an AC condenser preheating the air. I will be running an electric pump, so I will have an advantage at idle. |
bondo |
Feb 2 2005, 11:59 PM
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#2
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Practicing my perpendicular parking Group: Members Posts: 4,277 Joined: 19-April 03 From: Los Osos, CA Member No.: 587 Region Association: Central California |
Well there are two deltaTs. One is water to air, the other is engine to water. If you move a lot of water through the radiator but don't cool it as much, you may get the same amout of heat transferred to the air. But then that larger quantity of water is still pretty warm and can't take much more heat from the engine.. so the engine gets hotter and hotter until the deltaT is enough to reach a new equilibrium. If that point is above the boiling point of the coolant, you're in trouble (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif)
As far as the cooler corners of the radiator goes, it could be obstructions in the tubes, or just the way the radiator design works with the rest of the cooling system. |
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