The effect of micro jets on wall pressure for sonic under expanded flow

This paper presents the experimental results on the flow characteristics of a suddenly expanded flow from the convergent nozzle for sonic under expanded case. In the present study micro jets were used to investigate the wall pressure in the enlarged duct. Accordingly an active control in the form of...

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Main Authors:	Ashfaq, Syed, Khan, Sher Afghan
Format:	Article
Language:	English
Published:	IJERA 2014
Subjects:	TL787 Astronautics
Online Access:	http://irep.iium.edu.my/49916/ http://irep.iium.edu.my/49916/ http://irep.iium.edu.my/49916/1/2014_FEBRUARY_IJERA.pdf

id	iium-49916
recordtype	eprints
spelling	iium-499162018-06-20T05:12:25Z http://irep.iium.edu.my/49916/ The effect of micro jets on wall pressure for sonic under expanded flow Ashfaq, Syed Khan, Sher Afghan TL787 Astronautics This paper presents the experimental results on the flow characteristics of a suddenly expanded flow from the convergent nozzle for sonic under expanded case. In the present study micro jets were used to investigate the wall pressure in the enlarged duct. Accordingly an active control in the form of four micro jets 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 was employed. The area ratio (ratio of area of suddenly expanded duct to nozzle exit area) studied are 2.56, 3.24, 4.84 and 6.25. The length-to-diameter (i.e. L/D) ratio of the sudden expansion duct was varied from 10 to 1. To study the effect of micro jets on the quality of flow in the enlarged duct wall pressure was measured and from the results it is found that the micro jets do not disturb the flow field in the duct. From the results, it is also seen that for L/D in the range L/D = 10 and 8 the flow remains oscillatory mostly for all the area ratios. However, these oscillations are suppressed gradually with the increase in the area ratio, also for all the L/D in the range 3 to 6. The nozzle pressure ratio (NPR) was varied from 1 to 3, however, in the present paper results are presented for under expanded case to ascertain the effectiveness of the micro jets under the influence of favorable pressure gradient (i.e. Pe/Pa = 1.5). The present study explicitly reveals that, the wall pressure in a suddenly expanded axi-symmetric duct can be controlled by employing micro jets. IJERA 2014-02 Article PeerReviewed application/pdf en http://irep.iium.edu.my/49916/1/2014_FEBRUARY_IJERA.pdf Ashfaq, Syed and Khan, Sher Afghan (2014) The effect of micro jets on wall pressure for sonic under expanded flow. International Journal of Engineering Research and Application, 4 (3). pp. 32-38. ISSN 2248-9622 http://www.ijera.com/papers/Vol4_issue2/Version%205/D42051929.pdf
repository_type	Digital Repository
institution_category	Local University
institution	International Islamic University Malaysia
building	IIUM Repository
collection	Online Access
language	English
topic	TL787 Astronautics
spellingShingle	TL787 Astronautics Ashfaq, Syed Khan, Sher Afghan The effect of micro jets on wall pressure for sonic under expanded flow
description	This paper presents the experimental results on the flow characteristics of a suddenly expanded flow from the convergent nozzle for sonic under expanded case. In the present study micro jets were used to investigate the wall pressure in the enlarged duct. Accordingly an active control in the form of four micro jets 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 was employed. The area ratio (ratio of area of suddenly expanded duct to nozzle exit area) studied are 2.56, 3.24, 4.84 and 6.25. The length-to-diameter (i.e. L/D) ratio of the sudden expansion duct was varied from 10 to 1. To study the effect of micro jets on the quality of flow in the enlarged duct wall pressure was measured and from the results it is found that the micro jets do not disturb the flow field in the duct. From the results, it is also seen that for L/D in the range L/D = 10 and 8 the flow remains oscillatory mostly for all the area ratios. However, these oscillations are suppressed gradually with the increase in the area ratio, also for all the L/D in the range 3 to 6. The nozzle pressure ratio (NPR) was varied from 1 to 3, however, in the present paper results are presented for under expanded case to ascertain the effectiveness of the micro jets under the influence of favorable pressure gradient (i.e. Pe/Pa = 1.5). The present study explicitly reveals that, the wall pressure in a suddenly expanded axi-symmetric duct can be controlled by employing micro jets.
format	Article
author	Ashfaq, Syed Khan, Sher Afghan
author_facet	Ashfaq, Syed Khan, Sher Afghan
author_sort	Ashfaq, Syed
title	The effect of micro jets on wall pressure for sonic under expanded flow
title_short	The effect of micro jets on wall pressure for sonic under expanded flow
title_full	The effect of micro jets on wall pressure for sonic under expanded flow
title_fullStr	The effect of micro jets on wall pressure for sonic under expanded flow
title_full_unstemmed	The effect of micro jets on wall pressure for sonic under expanded flow
title_sort	effect of micro jets on wall pressure for sonic under expanded flow
publisher	IJERA
publishDate	2014
url	http://irep.iium.edu.my/49916/ http://irep.iium.edu.my/49916/ http://irep.iium.edu.my/49916/1/2014_FEBRUARY_IJERA.pdf
first_indexed	2023-09-18T21:10:31Z
last_indexed	2023-09-18T21:10:31Z
_version_	1777411221499150336

The effect of micro jets on wall pressure for sonic under expanded flow

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