Dan Ruggirello wrote:

Here are some results..............when animated, you can see the low
pressure eddy's from BL separation continuously rolling into the duct,

then

dissipating.  It appears that this run has full on BL separation.   I
probably should allow one of the other sims to run longer to verify if

they

too would have full on BL separtion.

Hmmmmm........inlet pressures through the duct seems lower than other

runs.

Dan

Dan; just a couple of comments on this one.  The idea is to have the
scoop entrance just aft of the bump compressing the boundary layer; so
shortening the scoop entrance can help in more ways than one.  Less
separation and high pressure turbulence.

The exit fairing is the right idea -  lowest drag is a faring that looks
like the top have of an airfoil - but in this case the exit area should
be decreased to further accelerate the exiting air and to cause less
turbulence on top.

Al

-Dan Ruggirello wrote:

Al,
I ran a couple simulations with the scoop aft of the bump with the first
batch of runs and it did seem to help keep the BL from separating, but I
would need to run it again for a longer time just to make sure.  The flow
through the radiator didn't seem like a great improvement.

There is probably an optimum exit area.  Too small pinches off flow and too
large creates too much drag.   In this case though, most of the turbulence
aft of the exit duct seems to be because of the BL separation from flow over
the bottom of the whole assembly.

Dan

 
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