Several of us in discussions while BillA was preparing his great
articles here and here wondered what the "worst case" power
dissipation over the WBs would be due to head loss over the
blocks and flow thru them. It is important to know this because
the power dissipation shows up as heat and must be considered
in the total heat the blocks must remove. Note that this heat is
intrinsic to the block at the various flow rates and is NOT the
heat supplied by the die simulator.
While some may be tempted to use Bernoulli Equations to
calculate this factor, this cannot be done because these
equations are only valid for streamlines i.e. non-turbulent
flow. It is not possible for Bill's equipment to measure the
temp change due to this effect, but as you will see, it does
become a serious factor especially a high flow.
While we all pretty much agreed on the "worst case" power
dissipation, I wanted to know more. The following graphs
come out of that study. They are based on Bill's measurments
on the WBs in his front page articles. After reviewing these
plots, it is hoped that we might discuss how this may be used
as a "correction factor" for doing what has been called the
hack known as C/W e have all come to know and love.
Here is a closeup of the range encounted by most OCers:
articles here and here wondered what the "worst case" power
dissipation over the WBs would be due to head loss over the
blocks and flow thru them. It is important to know this because
the power dissipation shows up as heat and must be considered
in the total heat the blocks must remove. Note that this heat is
intrinsic to the block at the various flow rates and is NOT the
heat supplied by the die simulator.
While some may be tempted to use Bernoulli Equations to
calculate this factor, this cannot be done because these
equations are only valid for streamlines i.e. non-turbulent
flow. It is not possible for Bill's equipment to measure the
temp change due to this effect, but as you will see, it does
become a serious factor especially a high flow.
While we all pretty much agreed on the "worst case" power
dissipation, I wanted to know more. The following graphs
come out of that study. They are based on Bill's measurments
on the WBs in his front page articles. After reviewing these
plots, it is hoped that we might discuss how this may be used
as a "correction factor" for doing what has been called the
hack known as C/W e have all come to know and love.
Here is a closeup of the range encounted by most OCers: