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Unread 11-17-2002, 11:28 AM   #20
Les
Cooling Savant
 
Join Date: Oct 2001
Location: Wigan UK
Posts: 929
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Quote:
Originally posted by unregistered
Les
quite excellent, extraordinary fit

define some terms for me
r = what amounts to the 'effective' area ?
so how did you arrive at this value ?
more crucially, is it a function of the (opposite side) die area - or the nozzle dia ?

I have difficulty understanding it being independent of the nozzle dia

the real value of H is 0.013m

a shame the nozzle configuration is so different

so why is the correspondence so good ?
a ‘monkeys typing the encyclopedia’ thing ? (distressing, don't like)

here, try another
the -U values are: D = 0.010, H = 0.005m
(I'm thinking we're gonna fall off the rails here)
Yes the agreement is somewhat scary and probably unreal but worthy of of further investigation.

Wanted to use two values for r
(1)the min value(2.5D) allowed,this gives the max h value,to use as as an "effective impingement area. area".
(2)an r value representative of the bp area (30mm?) to get by manipulation a value to use as "background convection"*.
However as 2.5D(36.25mm) in the 0.57"(14.5mm) case is larger than the bp area I decided,somewhat arbitarily, to use the same r value of 25mm. This 25mm was intended as representative of a 50x50mm bp.Unfortunately mid way thro calcs memory said a more realistic bp was 60x60mm and used this in Waterloo calcs. Probably should redo with r=30mm(and correction of D= 0.0145 not 0.014)but ... ..and quick look showed little difference.
Apologise if this is as clear as mud but .................
Can (and have 1/4 done,somewhere) the two r (and hence two h) sums when nozzle diam approaches 3mm.

Using "the real value of H is 0.013m" get
Get the same for "the -U values are: D = 0.010, H = 0.005m".
Will "Press (Calculate Now) to calculate anyway"for both cases,but allow a little time ........ slow and oft befuddled brain.
Dunno whether to change r to 30mm.



.* As used in last my post here (but called Wall Jet) http://forums.procooling.com/vbb/sho...5&pagenumber=7
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