Flow Visualization and Numerical Calculation in a Curved Diffuser

Effects of the Existence of a Rear Duct Connected at the Outlet of Curved Diffuser

Abstract

To date, flow visualization of the logarithmic spiral curved diffusers have been carried out under various conditions in order to clarify their flow patterns.
In this study, the effects of the existence of a rear duct connected at each outlet of the curved diffuser with different spiral angle on the flow pattern are clarified by the flow visualization using the dye-streak method and the condensed-milk method, and their results are compared with the numerical solutions obtained by the finite element method.
As a result of this study, it was found that the flow pattern in a curved diffuser was affected considerably by connecting rear duct of a suitable length at the outlet of a curved diffuser, and the flow pattern in a curved diffuser was improved by connecting a rear duct in any logarithmic spiral angle.