Pump pulling from CPU does it make a difference?

[prava]

Cross-sectional area decreases. Flow rate equals cross-sectional area times velocity, or Q=A*V. Flow rate, Q, must be constant everywhere, so by decreasing A (thinner tubing, nozzle in water block etc.), V must increase.


That's a little tricky. Individual water molecules will move in an unpredictable manner, so looking at just one won't work. What you do (one way to do it, at least) is imagine a tiny cube placed somewhere in the fluid flow and look at the average net number of water molecules entering and exiting each face of the cube. Skipping the rest of the details, this gives you a way to say in which direction, and how quickly, the water in the cube is moving on average. There's a lot more to this, but that would make a very long post not very relevant to water cooling. :P

THX!!!! Ahhh ok. So I already said that, just didnt realise what it was, hehe, what decreases is the area in which the water is moving (perpendicularly, of course) across...yet simple and clear

About speed...yes, I remember that when I was in high-school (physics class) when we used that stuff to calculate current as you use the same when using fluids...mmm can't remember the name of that "principle" or "law", my memory is not what used to be.

BTW, there is something going around, why do we need any pressure at all then? If the only thing we need is more flow (we can modify the speed of the water at our wish just modifying the width of the tube), when does pressure get into the equation? As far as I know, pressure would be useful in a non-closed loop when you've got a well and you need to pump up the water, but in this case I don't see the need for it...I know, i'm missing something again.

PD: yai, although not being that technical, having to understand something not that simple in a language you don't use in your everyday living makes everything more complicated (plus the inch/cm - liter/gallon stuff).