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EMC2 · 02-12-2002, 05:23 PM

Brad - It's one of those darn fangled US units

1/1000" (i.e. 1 mil = 0.001") 1 mm ~= 39.37 mils

Yes, it would be possible given more info... but I don't know that I'm so inclined at the moment

Volenti - a combination of both, although the model portions used are validated. Regarding the flow regimen : in this case a validated model for rectangular cross section channels. Used the physical parameters for pure water at the given temp (25C). The laminar/turbulent determination is based on the Reynold's number and done without any turbulence generating features added to the channels (i.e. purely flow rate dependent based on a relatively smooth channel wall with no turbulence inducing extras).

There's a fairly large body of research data in the area of altering flow regimen. ONE way is altering the surface of the channels properly. (properly here defined as in a way that introduces turbulence rather than one which induces laminar flow and does so without sacrificing effective surface area).

One further note: turbulence is a double edged sword, it is very good for heat transfer in this case but comes at the cost of an increased pressure drop (the amount of increase depends on the method used and the amount of turbulence generated <i.e. small scale or large scale>)

02-12-2002, 05:23 PM	#42
EMC2 Cooling Savant Join Date: Feb 2002 Location: Dark Side of the Moon Posts: 365	Afternoon blabbering Brad - It's one of those darn fangled US units 1/1000" (i.e. 1 mil = 0.001") 1 mm ~= 39.37 mils Yes, it would be possible given more info... but I don't know that I'm so inclined at the moment Volenti - a combination of both, although the model portions used are validated. Regarding the flow regimen : in this case a validated model for rectangular cross section channels. Used the physical parameters for pure water at the given temp (25C). The laminar/turbulent determination is based on the Reynold's number and done without any turbulence generating features added to the channels (i.e. purely flow rate dependent based on a relatively smooth channel wall with no turbulence inducing extras). There's a fairly large body of research data in the area of altering flow regimen. ONE way is altering the surface of the channels properly. (properly here defined as in a way that introduces turbulence rather than one which induces laminar flow and does so without sacrificing effective surface area). One further note: turbulence is a double edged sword, it is very good for heat transfer in this case but comes at the cost of an increased pressure drop (the amount of increase depends on the method used and the amount of turbulence generated <i.e. small scale or large scale>)