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Unread 12-15-2003, 11:15 PM   #41
Cathar
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Join Date: Sep 2002
Location: Melbourne, Australia
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Quote:
Originally posted by Aleck
As only the bottom part walls of the cavity is involved in the secondary impingement...so i was thingking if making helical groves on the walls will give added performance..?

The groves could be easily made by using a small inner threadmaker (taps)..

Theoriticaly, this will surely thin the boundary layer of the fluid flowing out of the cavity walls because of the turbulance created by the whirling effect
Yes, I had considered tapping the holes like you say. Aside from the difficulty of tapping into copper into such small holes and not breaking taps when doing so, I was concerned that the pitch of the thread would be such that no real swirling would develop as the vertical velocity is just too quick. Instead there may be a more dangerous scenario developing whereby the water inside the thread grooves remains fairly static and the water just rushes up the middle. I never directly experimented with it though.
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