Control of suddenly expanded flow at low supersonic Mach numbers

In the present study the experiments were conducted to control the base pressure from a convergent-divergent nozzle at low supersonic Mach numbers to assess the effectiveness of active control mechanism in the form of micro jets at different expansion level. The parameters considered in the presen...

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Main Authors: Chaudhury, Zakir Ilahi, Shinde, V.B, Syed, Syed Ashfaq, Khan, Sher Afghan
Format: Article
Language:English
Published: IJERA 2015
Subjects:
Online Access:http://irep.iium.edu.my/46619/
http://irep.iium.edu.my/46619/
http://irep.iium.edu.my/46619/1/D58052433.pdf
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spelling iium-466192015-12-29T08:27:53Z http://irep.iium.edu.my/46619/ Control of suddenly expanded flow at low supersonic Mach numbers Chaudhury, Zakir Ilahi Shinde, V.B Syed, Syed Ashfaq Khan, Sher Afghan TJ1040 Machinery exclusive of prime movers In the present study the experiments were conducted to control the base pressure from a convergent-divergent nozzle at low supersonic Mach numbers to assess the effectiveness of active control mechanism in the form of micro jets at different expansion level. The parameters considered in the present study are the diameter ratio, length to diameter ratio (L/D), Nozzle Pressure Ratio (NPR), and the Mach number. The diameter ratio selected for the present study are 1.6, 1.8, 2.2, and 2.5. Experiments were conducted for nozzle pressure ratio (NPR) from 3 to 11. The L/D ratio of the enlarged duct was varied from 10 to 1, and results are presented for L/D 4, 3, 2, and 1. The Mach numbers of the present studies are 1.1, 1.2, 1.4, and 1.5. The results show that the Micro jets are very effective and are able to raise the base pressure value to a considerable level under the influence of favorable pressure gradient except at lower NPR 3. At NPRs 5 and 7 for some cases the trends differ due to the level of expansion, nature of waves present in the base region, relief available to the flow, L/D ratio of the enlarged duct and the Mach numbers. It is seen that most of the cases exhibit similar behavior for the L/Ds in the range 4 and 3, which means; that the back pressure has not adversely influenced the flow field in the base region as well as in the duct. The minimum duct length required for the flow to be attached is L/D = 2, even though in some cases flow is attached with duct wall. With this it can be stated that the micro jets can be an alternative for the for base pressure control. Keywords - Base pressure, Length-to-diameter ratio, Mach number, Nozzle pressure ratio, Sudden expansion IJERA 2015-08 Article PeerReviewed application/pdf en http://irep.iium.edu.my/46619/1/D58052433.pdf Chaudhury, Zakir Ilahi and Shinde, V.B and Syed, Syed Ashfaq and Khan, Sher Afghan (2015) Control of suddenly expanded flow at low supersonic Mach numbers. International Journal of Engineering Research and Applications, 5 (8). pp. 24-33. ISSN 2248-9622. http://www.ijera.com/
repository_type Digital Repository
institution_category Local University
institution International Islamic University Malaysia
building IIUM Repository
collection Online Access
language English
topic TJ1040 Machinery exclusive of prime movers
spellingShingle TJ1040 Machinery exclusive of prime movers
Chaudhury, Zakir Ilahi
Shinde, V.B
Syed, Syed Ashfaq
Khan, Sher Afghan
Control of suddenly expanded flow at low supersonic Mach numbers
description In the present study the experiments were conducted to control the base pressure from a convergent-divergent nozzle at low supersonic Mach numbers to assess the effectiveness of active control mechanism in the form of micro jets at different expansion level. The parameters considered in the present study are the diameter ratio, length to diameter ratio (L/D), Nozzle Pressure Ratio (NPR), and the Mach number. The diameter ratio selected for the present study are 1.6, 1.8, 2.2, and 2.5. Experiments were conducted for nozzle pressure ratio (NPR) from 3 to 11. The L/D ratio of the enlarged duct was varied from 10 to 1, and results are presented for L/D 4, 3, 2, and 1. The Mach numbers of the present studies are 1.1, 1.2, 1.4, and 1.5. The results show that the Micro jets are very effective and are able to raise the base pressure value to a considerable level under the influence of favorable pressure gradient except at lower NPR 3. At NPRs 5 and 7 for some cases the trends differ due to the level of expansion, nature of waves present in the base region, relief available to the flow, L/D ratio of the enlarged duct and the Mach numbers. It is seen that most of the cases exhibit similar behavior for the L/Ds in the range 4 and 3, which means; that the back pressure has not adversely influenced the flow field in the base region as well as in the duct. The minimum duct length required for the flow to be attached is L/D = 2, even though in some cases flow is attached with duct wall. With this it can be stated that the micro jets can be an alternative for the for base pressure control. Keywords - Base pressure, Length-to-diameter ratio, Mach number, Nozzle pressure ratio, Sudden expansion
format Article
author Chaudhury, Zakir Ilahi
Shinde, V.B
Syed, Syed Ashfaq
Khan, Sher Afghan
author_facet Chaudhury, Zakir Ilahi
Shinde, V.B
Syed, Syed Ashfaq
Khan, Sher Afghan
author_sort Chaudhury, Zakir Ilahi
title Control of suddenly expanded flow at low supersonic Mach numbers
title_short Control of suddenly expanded flow at low supersonic Mach numbers
title_full Control of suddenly expanded flow at low supersonic Mach numbers
title_fullStr Control of suddenly expanded flow at low supersonic Mach numbers
title_full_unstemmed Control of suddenly expanded flow at low supersonic Mach numbers
title_sort control of suddenly expanded flow at low supersonic mach numbers
publisher IJERA
publishDate 2015
url http://irep.iium.edu.my/46619/
http://irep.iium.edu.my/46619/
http://irep.iium.edu.my/46619/1/D58052433.pdf
first_indexed 2023-09-18T21:06:21Z
last_indexed 2023-09-18T21:06:21Z
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