Active control of base pressure in supersonic regime
This paper presents an experimental investigation to study the effectiveness of micro jets to control base pressure in suddenly expanded axi-symmetric ducts. Four micro jets of 1-mm orifice dia located at 90° intervals along a pitch circle dia of 1.3 times the nozzle exit dia in the base region are...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
Institution of Engineers, India
2006
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| Subjects: | |
| Online Access: | http://irep.iium.edu.my/46703/ http://irep.iium.edu.my/46703/ http://irep.iium.edu.my/46703/ http://irep.iium.edu.my/46703/1/AS_151.pdf |
| Summary: | This paper presents an experimental investigation to study the effectiveness of micro jets to control base pressure in suddenly expanded axi-symmetric ducts. Four micro jets of 1-mm orifice dia located at 90° intervals along a pitch circle dia of 1.3 times the nozzle exit dia in the base region are employed as active controls. The Mach numbers at the entry to the suddenly expanded duct studied in the present study are 1.25, 1.30, 1.48, 1.60, 1.80, 2.00, 2.50 and 3.00. The jets are expanded suddenly into an axisymmetric tube with cross-sectional area 3.24 times that of nozzle exit area. The L/D ratio of the sudden expansion tube is varied from 10 to 1. As high as 40% increase in base pressure is achieved. It is found that the micro jets can serve as active controllers for base pressure. Also, the micro jets do not adversely influence the wall pressure distribution. |
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