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Originally Posted by Incoherent
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Les, a thought about the C/W vs BP thickness. I'm basing my numbers on a changing water/copper interface area using a 45 degree assumption. Waterloo is maintaining a constant interface area is it not?
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Yes, Waterloo uses "user defined" interface dimensions(in above case 50x50mm).
This corresponds to the "Flux Channel Dimensions"
It then calculates:
"One-D Resistance (C/W)" = Resistance of 50x50x*mm slab of Cu + Convective Resistance of 50x50mm surface/interface
"Spreading Resistance (C/W)" = The extra conductive resistance due to heat-source being smaller than flux channel.
"Total Resistance(C/W)"= "One-D Resistance (C/W)" + "Spreading Resistance (C/W)"
The "Spreading Resistance (C/W)" is Dependant on both h ( "Film Coeff", h(conv)no surface structure) and dimensions(both source and channel).
Not happy with the 45degree assumption.
Waterloo in effect calculates the correct angle for the thermal conditions.
I use
Isoflux Rectangles program, however they do
Non-Isoflux cases for disks.
I calculate to 6 digits and use 1000 "Terms"( have no justification for choice)
Note X-axis in my 2nd graph is wrongly labeled; should be "h(bp to fin) W/m*m*c)" - was early days and was very much struggling with designations(still am)