Control of ideally expanded and under expanded nozzle flows with micro jets

This paper presents an experimental investigation of an airflow from convergent-divergent axisymmetric nozzles expanded suddenly into circular duct of larger cross-sectional area than that of nozzle exit area, focusing attention on the base pressure and the flow development in the duct. To investiga...

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Main Authors:	G M, Fharukh Ahmed, Baig, Maugal Ahmed Ali, Bashir, Musavir, Khan, Sher Afghan
Format:	Article
Language:	English
Published:	International Organization of Scientific Research ( IOSR ) 2016
Subjects:	TJ163.26 Energy conservation
Online Access:	http://irep.iium.edu.my/54292/ http://irep.iium.edu.my/54292/ http://irep.iium.edu.my/54292/ http://irep.iium.edu.my/54292/1/Fharrukh-GM.pdf

id	iium-54292
recordtype	eprints
spelling	iium-542922017-01-25T01:59:12Z http://irep.iium.edu.my/54292/ Control of ideally expanded and under expanded nozzle flows with micro jets G M, Fharukh Ahmed Baig, Maugal Ahmed Ali Bashir, Musavir Khan, Sher Afghan TJ163.26 Energy conservation This paper presents an experimental investigation of an airflow from convergent-divergent axisymmetric nozzles expanded suddenly into circular duct of larger cross-sectional area than that of nozzle exit area, focusing attention on the base pressure and the flow development in the duct. To investigate the influence of active control on wall pressure as well as on the flow field developed in the duct, the micro jets of 1 mm orifice diameter located at 900 interval along a pitch circle diameter 1.3 times the nozzle exit diameter were employed as the controller of the base pressure. The Mach number investigated in the present study was 1.30. The area ratio of the present study was 2.56. The nozzle pressure ratio (NPR) used were from 2.77 and 4.16 respectively which corresponds to correct and under expanded conditions. The length-to-diameter ratio of the enlarged duct was varied from 10 to 1.The level of expansion at the nozzle exit (i.e. before sudden expansion) influences the wall pressure very strongly. When the micro jets were activated they found to influence the flow in the enlarged duct. Wall pressure results for correctly expanded and under expended jets indicate that the flow in the enlarged duct remains attached for L/Ds including at L/D =1. Also, it is found that the wall pressure flow field in the duct for with and without control are identical and the control in the form of the micro jets does disturb the flow field. Results for L/D = 8 and 10 for correctly expanded jets indicate peculiar phenomenon and are totally different from all the results for lower L/Ds. Wall pressure results for under expanded jets indicate that control results in marginal decrease in the wall pressure otherwise the wall pressure flow field with and without control remains same. International Organization of Scientific Research ( IOSR ) 2016-12 Article PeerReviewed application/pdf en http://irep.iium.edu.my/54292/1/Fharrukh-GM.pdf G M, Fharukh Ahmed and Baig, Maugal Ahmed Ali and Bashir, Musavir and Khan, Sher Afghan (2016) Control of ideally expanded and under expanded nozzle flows with micro jets. IOSR journal of Mechanical & Civil Engineering ( IOSR-JMCE), 18 (6). pp. 83-89. ISSN 2320-334x E-ISSN 2278-1684 http://www.iosrjournals.org/iosr-jmce/papers/i-%20CAM2K16-2016/Mech/Volume%203/14.%2083-89.pdf 10.9790/1684-16053038389
repository_type	Digital Repository
institution_category	Local University
institution	International Islamic University Malaysia
building	IIUM Repository
collection	Online Access
language	English
topic	TJ163.26 Energy conservation
spellingShingle	TJ163.26 Energy conservation G M, Fharukh Ahmed Baig, Maugal Ahmed Ali Bashir, Musavir Khan, Sher Afghan Control of ideally expanded and under expanded nozzle flows with micro jets
description	This paper presents an experimental investigation of an airflow from convergent-divergent axisymmetric nozzles expanded suddenly into circular duct of larger cross-sectional area than that of nozzle exit area, focusing attention on the base pressure and the flow development in the duct. To investigate the influence of active control on wall pressure as well as on the flow field developed in the duct, the micro jets of 1 mm orifice diameter located at 900 interval along a pitch circle diameter 1.3 times the nozzle exit diameter were employed as the controller of the base pressure. The Mach number investigated in the present study was 1.30. The area ratio of the present study was 2.56. The nozzle pressure ratio (NPR) used were from 2.77 and 4.16 respectively which corresponds to correct and under expanded conditions. The length-to-diameter ratio of the enlarged duct was varied from 10 to 1.The level of expansion at the nozzle exit (i.e. before sudden expansion) influences the wall pressure very strongly. When the micro jets were activated they found to influence the flow in the enlarged duct. Wall pressure results for correctly expanded and under expended jets indicate that the flow in the enlarged duct remains attached for L/Ds including at L/D =1. Also, it is found that the wall pressure flow field in the duct for with and without control are identical and the control in the form of the micro jets does disturb the flow field. Results for L/D = 8 and 10 for correctly expanded jets indicate peculiar phenomenon and are totally different from all the results for lower L/Ds. Wall pressure results for under expanded jets indicate that control results in marginal decrease in the wall pressure otherwise the wall pressure flow field with and without control remains same.
format	Article
author	G M, Fharukh Ahmed Baig, Maugal Ahmed Ali Bashir, Musavir Khan, Sher Afghan
author_facet	G M, Fharukh Ahmed Baig, Maugal Ahmed Ali Bashir, Musavir Khan, Sher Afghan
author_sort	G M, Fharukh Ahmed
title	Control of ideally expanded and under expanded nozzle flows with micro jets
title_short	Control of ideally expanded and under expanded nozzle flows with micro jets
title_full	Control of ideally expanded and under expanded nozzle flows with micro jets
title_fullStr	Control of ideally expanded and under expanded nozzle flows with micro jets
title_full_unstemmed	Control of ideally expanded and under expanded nozzle flows with micro jets
title_sort	control of ideally expanded and under expanded nozzle flows with micro jets
publisher	International Organization of Scientific Research ( IOSR )
publishDate	2016
url	http://irep.iium.edu.my/54292/ http://irep.iium.edu.my/54292/ http://irep.iium.edu.my/54292/ http://irep.iium.edu.my/54292/1/Fharrukh-GM.pdf
first_indexed	2023-09-18T21:16:49Z
last_indexed	2023-09-18T21:16:49Z
_version_	1777411618247802880

Control of ideally expanded and under expanded nozzle flows with micro jets

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