I. H. Ibrahim
The Journal of Mechanical Science and Technology, vol. 22, no. 10, pp.1993-1997, 2008

Abstract : Intake geometries result in unwanted secondary flows and formations of vortices which affect the engine performance. This paper investigates the effects of the curvature and cross-sectional shape transitioning of the actual F-5 duct. Two additional different geometries were set up to isolate each parameter; a circular cross-sectional duct with similar centerline configuration and a straight duct with similar cross-sectional transitioning as the F-5 duct. To measure the efficiency of duct flow, the distortion index (DC (60)) and pressure recovery are used. It is found that the straight duct with similar cross-sectional transitioning as the F-5 intake resulted in a 2.1% increase in pressure recovery and an 86% decrease in distortion when compared with the baseline intake. Also, the baseline intake resulted in a 0.5% increase in pressure recovery and a 15% decrease in distortion compared to the constant circular cross-sectional duct.

Keyword : S-duct; Curved diffuser; Cross-sectional shape; F-5; Distortion; Recovery