Accession Number : AD0786887

Title :   Flow Regimes in Two-Dimensional Ribbed Diffusers.

Descriptive Note : Final rept. Oct 70-Jun 71,

Corporate Author : AIR FORCE AERO PROPULSION LAB WRIGHT-PATTERSON AFB OHIO

Personal Author(s) : Stull,Frank D.

Report Date : JUN 1974

Pagination or Media Count : 50

Abstract : Water table flow visualization tests of a straight wall diffuser and corresponding ribbed diffuser were conducted over a wide range of total divergence angles and diffuser length to throat width ratios. Rib parameters such as inter-rib cavity depth to width ratio, inter-rib cavity width, rib thickness and number of ribs were varied, as well as rib contour. Motion pictures were obtained of the secondary flow patterns occurring within the inter-rib cavities, and hot film measurements were made to determine the extent of velocity fluctuations induced by the cavities. In general, the addition of ribs increased the no-appreciable stall regime by increasing velocity fluctuations near the wall of the diffuser, thereby promoting momentum exchange. (Author)

Descriptors :   *Diffusers, *Fluid flow, Flow separation, Flow visualization, Boundary layer, Test methods

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE