Effect of mach number on wall pressure flow field for area ratio 2.56

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

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Main Authors: Ashfaq, Syed, Khan, Sher Afghan
Format: Article
Language:English
Published: International Organozation of Scientific Research (IOSR) Journals 2014
Subjects:
Online Access:http://irep.iium.edu.my/49919/
http://irep.iium.edu.my/49919/1/2014_MARCH_APRIL_IOSR_JMCE.pdf
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author Ashfaq, Syed
Khan, Sher Afghan
author_facet Ashfaq, Syed
Khan, Sher Afghan
author_sort Ashfaq, Syed
building IIUM Repository
collection Online Access
description This paper presents the experimental results on the flow characteristics of a suddenly expanded flow from the convergent nozzle for subsonic flow. In the present study micro jets were used to investigate the effect of micro jets on wall pressure flow field 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 Mach numbers of the present studies were M = 0.9, 0.8, and 0.6 and the area ratio (ratio of area of suddenly expanded duct to nozzle exit area) studied was 2.56. The length-to-diameter (i.e. L/D) ratio of the sudden expansion duct was varied from 10 to 1. From the results, it is seen that the flow in the base region is dominated by the waves, the general perception what we have that correctly expanded flow will be from waves is proved to be wrong; also, it is found that for L/D in the range L/D = 10 and 8 the flow remains oscillatory mostly for all the Mach numbers. However, these oscillations are suppressed gradually either with the increase in the L/D ratio in the range 3 to 6 or with decrease in the level of inertia level. The present study explicitly reveals that, the wall pressure in a suddenly expanded axi-symmetric duct can be controlled by employing micro jets. Since the flow field in the enlarged duct remained undisturbed hence, we can say that the control in the form of micro jets don’t disturb the field.
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spelling iium-499192018-06-20T06:42:24Z http://irep.iium.edu.my/49919/ Effect of mach number on wall pressure flow field for area ratio 2.56 Ashfaq, Syed Khan, Sher Afghan TL500 Aeronautics This paper presents the experimental results on the flow characteristics of a suddenly expanded flow from the convergent nozzle for subsonic flow. In the present study micro jets were used to investigate the effect of micro jets on wall pressure flow field 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 Mach numbers of the present studies were M = 0.9, 0.8, and 0.6 and the area ratio (ratio of area of suddenly expanded duct to nozzle exit area) studied was 2.56. The length-to-diameter (i.e. L/D) ratio of the sudden expansion duct was varied from 10 to 1. From the results, it is seen that the flow in the base region is dominated by the waves, the general perception what we have that correctly expanded flow will be from waves is proved to be wrong; also, it is found that for L/D in the range L/D = 10 and 8 the flow remains oscillatory mostly for all the Mach numbers. However, these oscillations are suppressed gradually either with the increase in the L/D ratio in the range 3 to 6 or with decrease in the level of inertia level. The present study explicitly reveals that, the wall pressure in a suddenly expanded axi-symmetric duct can be controlled by employing micro jets. Since the flow field in the enlarged duct remained undisturbed hence, we can say that the control in the form of micro jets don’t disturb the field. International Organozation of Scientific Research (IOSR) Journals 2014-03 Article PeerReviewed application/pdf en http://irep.iium.edu.my/49919/1/2014_MARCH_APRIL_IOSR_JMCE.pdf Ashfaq, Syed and Khan, Sher Afghan (2014) Effect of mach number on wall pressure flow field for area ratio 2.56. IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE), 11 (2). pp. 56-64. ISSN 2320-334X E-ISSN 2278-1684 http://www.iosrjournals.org/iosr-jmce/papers/vol11-issue2/Version-1/I011215664.pdf 10.9790/1684-11215664
spellingShingle TL500 Aeronautics
Ashfaq, Syed
Khan, Sher Afghan
Effect of mach number on wall pressure flow field for area ratio 2.56
title Effect of mach number on wall pressure flow field for area ratio 2.56
title_full Effect of mach number on wall pressure flow field for area ratio 2.56
title_fullStr Effect of mach number on wall pressure flow field for area ratio 2.56
title_full_unstemmed Effect of mach number on wall pressure flow field for area ratio 2.56
title_short Effect of mach number on wall pressure flow field for area ratio 2.56
title_sort effect of mach number on wall pressure flow field for area ratio 2.56
topic TL500 Aeronautics
url http://irep.iium.edu.my/49919/
http://irep.iium.edu.my/49919/
http://irep.iium.edu.my/49919/
http://irep.iium.edu.my/49919/1/2014_MARCH_APRIL_IOSR_JMCE.pdf