Effect of the external parallel acoustic excitation on the adverse pressure gradient (APG)
Other Title(s)
تأثير الإثارة الخارجية الصوتية الموازية على انحدار الضغط العكسي
Joint Authors
Sahib, Ibtisam Mahdi
Husayn, Iman Shakir
Abd al-Hadi, Hana
Source
The Iraqi Journal for Mechanical and Materials Engineering
Issue
Vol. 16, Issue 2 (30 Jun. 2016), pp.100-116, 17 p.
Publisher
University of Babylon College of Engineering
Publication Date
2016-06-30
Country of Publication
Iraq
No. of Pages
17
Main Subjects
Abstract EN
There was a needed for a technique to be able to enhance the flow properties by decreasing the velocity in (APG) Adverse Pressure Gradient and increasing the skin friction .The present work used a technique of the effect of external parallel acoustic excitation on the Adverse Pressure Gradient (APG) over a rough surface and smooth surface for a turbulent flow.
This study was conducted at fully developed turbulent flow with a Reynolds number based on hydraulic diameter (8.3×104).
The experimental ducts test carried out in wind tunnel manufactured from Perspex (250mmx250mm) and length of 690 mm .
A Preston tube was used to measure the air flow velocity profile, pressure distribution and skin friction.
The adverse pressure gradient was produced in unsymmetrical diffuser with three different diffuser angles (8, 11,and 15) degree.
The external excitation was parallel to the flow , and the excitation frequency (150) Hz and SPL (95 ) dB were used in this study .
The obtained results showed that the performance, and other flow characteristics of diffusers depend on the angle of diffuser and acoustic excitation, and indicated that the surface roughness enhanced the production of turbulence as well as the turbulence level when compared with the smooth-wall data.
It is well known that both wall roughness and APG reduce the mean velocity close to the wall.
The rough surface with the external parallel excitation effect are regarded as the key parameters to enhance the flow characteristics, this technique is able to decrease the velocity and increase the skin friction and to enhance the flow properties and thus improve the flow structure.
Kay words ; parallel external excitation , wind tunnel , at fully developed turbulent , flow velocity profile, pressure distribution ,skin friction .
American Psychological Association (APA)
Abd al-Hadi, Hana& Sahib, Ibtisam Mahdi& Husayn, Iman Shakir. 2016. Effect of the external parallel acoustic excitation on the adverse pressure gradient (APG). The Iraqi Journal for Mechanical and Materials Engineering،Vol. 16, no. 2, pp.100-116.
https://search.emarefa.net/detail/BIM-750717
Modern Language Association (MLA)
Abd al-Hadi, Hana…[et al.]. Effect of the external parallel acoustic excitation on the adverse pressure gradient (APG). The Iraqi Journal for Mechanical and Materials Engineering Vol. 16, no. 2 (2016), pp.100-116.
https://search.emarefa.net/detail/BIM-750717
American Medical Association (AMA)
Abd al-Hadi, Hana& Sahib, Ibtisam Mahdi& Husayn, Iman Shakir. Effect of the external parallel acoustic excitation on the adverse pressure gradient (APG). The Iraqi Journal for Mechanical and Materials Engineering. 2016. Vol. 16, no. 2, pp.100-116.
https://search.emarefa.net/detail/BIM-750717
Data Type
Journal Articles
Language
English
Notes
Includes bibliographical references : p. 116
Record ID
BIM-750717