Annubar bench design

[turbodig]

Hi,

I'm planning an annubar bench, and was wondering about a
couple things... (Crude drawing shown below)




Regarding the flow straighteners, is it better to have them
closer to the annubar or like I have them in the pic?

I'm essentially using the box as a plenum, and it has a
fair amount of volume. I'm hoping it won't be too much volume
to pull a good depression? (using 4 Ametek vacuum motors)

I've also found some Freescale 5v differential pressure senders
that do a 1.45 PSI range. Gonna try them with my Labjack DAC
system to try to calculate airflow on the fly. Step 2 is to use the
Labjack to control motor speed to keep the depression constant,
but I'm trying to limit myself to one project at a time..

Thanks,

Dig

[bruce]

I wouldn't see why this would not work. I personally don't like the large plenum and then the flow going into the pipe, but thats just my thoughts and should not sway you in your design. I'm finding there are more than one way to measure airflow . . .

[84-1074663779]

Agree with Bruce, it looks o/k and should work.

How about fitting a large gently flared entry from the plenum into the flow straightener ? This will gather and accelerate the air and point it in the right direction. Otherwise there might be a fairly high pressure drop where the air tries to enter the flow straightener.

In theory an exponential horn will give constant acceleration to the air over its length. Something like a musical instrument flare shape.

[turbodig]