Abstract
This paper presents an experimental investigation carried out to control the base pressure in suddenly expanded flows using ribs as passive control. Flow from circular convergent nozzle expanding suddenly into 2.2 times larger area circular pipe with ribs at different locations in pipe is studied for subsonic, correctly expanded and underexpanded sonic flow regimes. The three annular ribs of aspect ratios 0.45, 0.64 and 1.25 are placed at three different axial locations 0.5 D, 1.0 D and 1.5 D in the larger area duct. The Mach number is varied from 0.2 to 1.0 in subsonic regime and NPR is varied from NPR 2 to 5 for the underexpanded sonic flow. The pressure at the nozzle base and the wall pressure distribution in the enlarged duct are measured for different ribs placed at different locations. The influence of rib on the base pressure and the wall pressure distribution of the enlarged duct are discussed. The results shows that rib can serve as an effective passive control to achieve a desired base pressure without introducing violent oscillations to the enlarged duct pressure field.
| Original language | English |
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| Title of host publication | 2nd International Conference on Recent Advances in Experimental Fluid Mechanics, 3-6 March 2008 |
| Publication status | Published - 03 Mar 2008 |