Abstract

The present study deals with incompressible turbulent flow. The flow
regarded as fully developed in two-dimensional diffuser. For completion of this
study a number of test models of modified diffusers designed and manufactured
with a six modified diffuser models were designed and manufactured with (3, 4
mm) permeable slot and each with (10◦ ,15◦ , 20◦) divergent angle . The air was
used as working fluid during the experimental Program at different Reynolds
numbers ranging between (6.85 × 104) to (1.64 × 105) at the duct inlet.
The results obtained showed that location of separation delayed by decreasing
the divergent angle and increasing the Reynolds number. The static pressure
coefficient recovery increased with the decreasing the diffuser area ratio
(AR).Also, the width of the permeable slot (4mm) in the modified diffuser at
divergent angles (10◦,15◦,20◦), enhances the static pressure coefficient recovery
(Cp) over the case of permeable slot of (3mm) with (23.25%),( 27.33%), and
(33.61%), respectively, and for the case of permeable slot of (2mm) with
(29.22%), (34.74%) and (40.88%), respectively, and with the case of no
permeable slot with (410.13%) , (44.09%), and (51.01%), respectively.