When you say 'derive optimal orifice size' do you mean the 'water area' of 'a cross section' of the block?(sorry about my terminology).
Is it best to have the block H2o area equal or slightly larger than tube bore?, for less 'back pressure' after the 'jetted' part?. or is the whole block slightly smaller so the whole thing is a 'high pressure' spot,(terminology?). I mean do you want to maintane the velocity all through the block or 'just' over the core. does it decrease overall pressure the longer the restriction is held(whole block) rather than just a restricted nozzle over core?. would it even work if the whole block was'nt restricted?.
My guess is the whole block but I have to ask
...
I thought max heatload would be relevant?. would thicker BP mean the fins overlapping the core by more than 2mm?(wider spread?). Is there a program like Radiate(I've not seen it yet) that shows you heat~spread but shows what H2o at various rates/speeds would remove as well?, to various shape/designs?. There should be!
. Any thermal/fluid software you'd recomend?.
Thanx!, and thanx again!...