Effect of area ratio on base pressure in a suddenly expanded duct for under expanded flow ft mach 1.87

Baig, Maugal Ahmed Ali and Khan, Sher Afghan and Khan, Mohammad Yunus (2012) Effect of area ratio on base pressure in a suddenly expanded duct for under expanded flow ft mach 1.87. International Journal of Mechanical and Industrial Engineering, 2 (2). pp. 86-90. ISSN 2231-6477

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Abstract

The results of an experimental investigation carried out to control the base pressure in a suddenly expanded axi-symmetric passage is presented in this paper. An active control in the form of micro jets is employed to control the base pressure. Air injection at four locations at the base, symmetric to the nozzle axis is used as the active control. The jet Mach number studied and the area ratios are 1.87, and 2.56, 3.24, 4.84, and 6.25. The L/D ratio is varied from 10 to 1. The experiments are conducted at a fixed level of under expansion (i.e. Pe/Pa = 1.5). In addition to base pressure, wall pressure field along the duct was also measured. As high as 80 percent increase in base pressure was achieved for certain combination of parameters of the present study. The minimum Length-to diameter ratio of the duct required is L/D = 2 for area ratios 6.25 and 4.84. Whereas, this requirement is L/D = 1 for area ratios 2.56 and 3.24.

Item Type:	Article (Journal)
Additional Information:	7395/49922
Uncontrolled Keywords:	Microjets, Wall pressure, L/D Ratio, Area ratio
Subjects:	T Technology > TL Motor vehicles. Aeronautics. Astronautics T Technology > TL Motor vehicles. Aeronautics. Astronautics > TL500 Aeronautics
Kulliyyahs/Centres/Divisions/Institutes (Can select more than one option. Press CONTROL button):	Kulliyyah of Engineering > Department of Mechanical Engineering
Depositing User:	Prof. Dr. Sher Afghan Khan
Date Deposited:	15 Apr 2016 16:07
Last Modified:	20 Jul 2016 14:56
URI:	http://irep.iium.edu.my/id/eprint/49922

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