I am looking for a detailed study on the pressure drop through a
perforated screen or slat-screen in a oscillatory
(harmonic-sinusoidal) or steady flow (water).  In particular, what is
the influence of the angle of the screen in the flow?  How does the
pressure drop change with angle of screens?  Similarly, what is the
change in drag (coefficient) with angle?

Seems like firms providing filters woould have this data.

Do your filters break up air bubbles or do they become blocked with
sand and other such?

All temperatures and pressures or a certain range?  Cavatation or no?