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rocketmanx · 12-09-2003, 08:49 PM

Here's a pretty good explenation of jet impingment cooling- Vision Engineering

The boundary layer is a ctually at the area of impact. The boundary layer as I've read about it and understand, is a layer at the point of contact between the medium to be cooled (copper in this case) and the cooling medim- water. There's a layer at the surface where the water and copper aren't actually "touching" each other due to a very fine layer of the "boundary" between the 2. It's kinda like "approaches zero but never equals zero". The impact thins this boundary layer through impact or "impinging" on the boundary layer, in other words it forces it's way through the layer a little and helps cooling.
I think of it as, if 2 pieces of perfectly flat copper were pressed together very hard the 2 pieces would still have a very tiny "boundary" layer wetween them because they aren't atomicaly bonded like a solid piece of copper. The same with the water running over a piece of copper, but worse. The force of the impingement jet basically gets the water closer to the copper. We all know that the more layers heat/energy has to travel through the more get lost in the transfer from one layer to the other.

Maybe a bit to long an expleantion there but I was very interested in finding out why Cathar's block worked so well. So I did a little research

If I'm off in my understanding please correct me as I could only find bits here and there.

12-09-2003, 08:49 PM	#22
rocketmanx Cooling Savant Join Date: Nov 2003 Location: Indiana Posts: 127	Here's a pretty good explenation of jet impingment cooling- Vision Engineering The boundary layer is a ctually at the area of impact. The boundary layer as I've read about it and understand, is a layer at the point of contact between the medium to be cooled (copper in this case) and the cooling medim- water. There's a layer at the surface where the water and copper aren't actually "touching" each other due to a very fine layer of the "boundary" between the 2. It's kinda like "approaches zero but never equals zero". The impact thins this boundary layer through impact or "impinging" on the boundary layer, in other words it forces it's way through the layer a little and helps cooling. I think of it as, if 2 pieces of perfectly flat copper were pressed together very hard the 2 pieces would still have a very tiny "boundary" layer wetween them because they aren't atomicaly bonded like a solid piece of copper. The same with the water running over a piece of copper, but worse. The force of the impingement jet basically gets the water closer to the copper. We all know that the more layers heat/energy has to travel through the more get lost in the transfer from one layer to the other. Maybe a bit to long an expleantion there but I was very interested in finding out why Cathar's block worked so well. So I did a little research If I'm off in my understanding please correct me as I could only find bits here and there. Last edited by rocketmanx; 12-09-2003 at 08:55 PM.