Passive control of base drag employing dimple in subsonic suddenly expanded flow

This paper presents an experimental and computational investigation to study the effectiveness of dimples to control the base pressure in Backward facing step (BFS) for various Nozzle pressure ratio (NPR) having Compressible flow to minimize the base drag. Two dimples of 3 mm diameter located at 180...

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Main Authors:	Khan, Sher Afghan, Asad Ullah, Mohammed, Sadiq, Jafar
Format:	Article
Language:	English English
Published:	The International Journals of Engineering and Sciences (IJENS) 2018
Subjects:	TL1 Motor vehicles
Online Access:	http://irep.iium.edu.my/64531/ http://irep.iium.edu.my/64531/ http://irep.iium.edu.my/64531/7/64531%20Passive%20Control%20of%20Base%20Drag%20Employing.pdf http://irep.iium.edu.my/64531/13/64531_Passive%20control%20of%20base%20drag%20employing%20dimple%20in%20subsonic%20suddenly%20expanded%20flow_scopus.pdf

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recordtype	eprints
spelling	iium-645312019-03-14T02:30:37Z http://irep.iium.edu.my/64531/ Passive control of base drag employing dimple in subsonic suddenly expanded flow Khan, Sher Afghan Asad Ullah, Mohammed Sadiq, Jafar TL1 Motor vehicles This paper presents an experimental and computational investigation to study the effectiveness of dimples to control the base pressure in Backward facing step (BFS) for various Nozzle pressure ratio (NPR) having Compressible flow to minimize the base drag. Two dimples of 3 mm diameter located at 1800 interval along pitch circle diameter of 23 mm in the base region was employed as passive controls. The test was conducted for NPR 1.27, 1.38, 1.52 and 1.69. The model is designed in such a way so as to provide four BFS with angle of incidence as 150 from which the flow suddenly expands to a square duct of 25 mm. The experimental investigation is carried out for different length of duct 4D≤L≤10D to see the influence of geometric parameter on base pressure. From the present investigation, it was found that dimples as passive control is very effective at higher NPR and the wall pressure distribution too was quite stable at higher NPR. Also the geometric parameter was found to influence the base pressure for a particular NPR. Computational investigation using commercial CFD tool shows pressure and velocity distribution profile for both dimple and non-dimple control. Tests are carried out by using Navier-stokes equation, Turbulence model as SST, Reynolds number (Re) =122.56×103. From this investigation it is clear that for a given nozzle pressure ratio one can find optimum L/D ratio which will result in maximum increase/decrease of base pressure and dimples can be effective passive controller for reducing base drag without disturbing the flow field. The International Journals of Engineering and Sciences (IJENS) 2018-06 Article PeerReviewed application/pdf en http://irep.iium.edu.my/64531/7/64531%20Passive%20Control%20of%20Base%20Drag%20Employing.pdf application/pdf en http://irep.iium.edu.my/64531/13/64531_Passive%20control%20of%20base%20drag%20employing%20dimple%20in%20subsonic%20suddenly%20expanded%20flow_scopus.pdf Khan, Sher Afghan and Asad Ullah, Mohammed and Sadiq, Jafar (2018) Passive control of base drag employing dimple in subsonic suddenly expanded flow. International Journal of Mechanical & Mechatronics Engineering, 18 (3). pp. 69-74. ISSN 2227-2771 E-ISSN 2077-124X http://ijens.org/Vol_18_I_03/181303-5757-IJMME-IJENS.pdf
repository_type	Digital Repository
institution_category	Local University
institution	International Islamic University Malaysia
building	IIUM Repository
collection	Online Access
language	English English
topic	TL1 Motor vehicles
spellingShingle	TL1 Motor vehicles Khan, Sher Afghan Asad Ullah, Mohammed Sadiq, Jafar Passive control of base drag employing dimple in subsonic suddenly expanded flow
description	This paper presents an experimental and computational investigation to study the effectiveness of dimples to control the base pressure in Backward facing step (BFS) for various Nozzle pressure ratio (NPR) having Compressible flow to minimize the base drag. Two dimples of 3 mm diameter located at 1800 interval along pitch circle diameter of 23 mm in the base region was employed as passive controls. The test was conducted for NPR 1.27, 1.38, 1.52 and 1.69. The model is designed in such a way so as to provide four BFS with angle of incidence as 150 from which the flow suddenly expands to a square duct of 25 mm. The experimental investigation is carried out for different length of duct 4D≤L≤10D to see the influence of geometric parameter on base pressure. From the present investigation, it was found that dimples as passive control is very effective at higher NPR and the wall pressure distribution too was quite stable at higher NPR. Also the geometric parameter was found to influence the base pressure for a particular NPR. Computational investigation using commercial CFD tool shows pressure and velocity distribution profile for both dimple and non-dimple control. Tests are carried out by using Navier-stokes equation, Turbulence model as SST, Reynolds number (Re) =122.56×103. From this investigation it is clear that for a given nozzle pressure ratio one can find optimum L/D ratio which will result in maximum increase/decrease of base pressure and dimples can be effective passive controller for reducing base drag without disturbing the flow field.
format	Article
author	Khan, Sher Afghan Asad Ullah, Mohammed Sadiq, Jafar
author_facet	Khan, Sher Afghan Asad Ullah, Mohammed Sadiq, Jafar
author_sort	Khan, Sher Afghan
title	Passive control of base drag employing dimple in subsonic suddenly expanded flow
title_short	Passive control of base drag employing dimple in subsonic suddenly expanded flow
title_full	Passive control of base drag employing dimple in subsonic suddenly expanded flow
title_fullStr	Passive control of base drag employing dimple in subsonic suddenly expanded flow
title_full_unstemmed	Passive control of base drag employing dimple in subsonic suddenly expanded flow
title_sort	passive control of base drag employing dimple in subsonic suddenly expanded flow
publisher	The International Journals of Engineering and Sciences (IJENS)
publishDate	2018
url	http://irep.iium.edu.my/64531/ http://irep.iium.edu.my/64531/ http://irep.iium.edu.my/64531/7/64531%20Passive%20Control%20of%20Base%20Drag%20Employing.pdf http://irep.iium.edu.my/64531/13/64531_Passive%20control%20of%20base%20drag%20employing%20dimple%20in%20subsonic%20suddenly%20expanded%20flow_scopus.pdf
first_indexed	2023-09-18T21:31:35Z
last_indexed	2023-09-18T21:31:35Z
_version_	1777412546716762112

Passive control of base drag employing dimple in subsonic suddenly expanded flow

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