Effects of inclination angle of ribs on the flow behavior in rectangular ducts
Author
Summary, in English
The flow behavior in rib-roughened ducts is influenced by the inclination of ribs and the effect is investigated in the present study by Particle Image Velocimetry (PIV). The local flow structures between two adjacent ribs were measured. The Reynolds number was fixed at 5800. The flow field description was based on the PIV results in planes both parallel and perpendicular to the ribbed walls at various locations. The rib angle to the main flow direction was varied as 30 deg, 45 deg, 60 deg and 90 deg. The ribs induce three dimensional flow fields. The flow separation and reattachment between adjacent ribs are clearly observed. In addition, the inclined ribs are found to alter the spanwise distribution of the streamwise velocity component. The streamwise velocity component has its highest values at the upstream end of the ribs, and decreases continuously to its lowest values at the downstream end. Strong secondary flow motion occurs over the entire duct cross section for the inclined ribs. The flow structures between two consecutive ribs show that the fluid flows along the ribs from one end of the ribs to the other end, and then turns back at the transverse center Downwash and upwash flows are observed at the upstream end and downstream end of the ribs, respectively.
Department/s
Publishing year
2004
Language
English
Pages
692-699
Publication/Series
Journal of Fluids Engineering
Volume
126
Issue
4
Document type
Journal article
Publisher
American Society Of Mechanical Engineers (ASME)
Topic
- Energy Engineering
Status
Published
ISBN/ISSN/Other
- ISSN: 0098-2202