Studies on flow from convergent nozzle with sudden expansion and control effectiveness under the influence of micro jets

Ashfaq, Syed and Khan, Sher Afghan (2013) Studies on flow from convergent nozzle with sudden expansion and control effectiveness under the influence of micro jets. International Journal of Research in Mechanical Engineering & Technology (IJRMET) , 4 (1). pp. 76-87. ISSN 2249-5770 E-ISSN 2249-5762

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Abstract

Sudden expansion fluid flow is of great importance. In the present study experiments are conducted to control the base pressure from a convergent nozzle. Active control in the form of micro jets are used as an active control of 1 mm orifice diameter located at 900 intervals along a pitch circle diameter of 1.3 times the nozzle exit diameter in the base region. Area ratio of the present study i.e. ratio of area of suddenly expanded duct to nozzle exit area studied is 4.84. Nozzle pressure ratio (NPR) and length-to-diameter (L/D) ratio are main geometric and inertia parameters considered in the present study. Accordingly, Tests are conducted for NPR in the range of 1.5 to 3.0, in the steps of 0.5. L/D ratio of the enlarged duct was considered are from 10 to 1, and tests were carried out for L/D 10, 8, 6, 5, 4, 3, 2 and 1. From the experimental studies, it is found that, unlike in the case of passive controls, the favourable pressure gradient does not ensure augmentation of the control effectiveness for active control in the form of micro jets. It is found that it is case sensitive as with increase in the NPR the wave pattern at the base region will be changing continuously. Further, it is found that the micro jets are activated they do not disturb the flow field in the enlarged duct.

Item Type:	Article (Journal)
Additional Information:	7395/49891
Uncontrolled Keywords:	Base Pressure, Wall Pressure, Nozzle Pressure Ratio, Active Control, Micro Jets
Subjects:	T Technology > TL Motor vehicles. Aeronautics. Astronautics
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:	29 Mar 2016 10:46
Last Modified:	18 Jul 2016 10:49
URI:	http://irep.iium.edu.my/id/eprint/49891

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