Effect of roughness on pressure fluctuations in a turbulent channel flow
Effect of roughness on pressure fluctuations in a turbulent channel flow
Direct numerical simulation is used to investigate the nature of pressure fluctuations induced by surface roughness in a turbulent channel flow at Re_\tau =400 for three-dimensional periodic roughness elements, whose peaks overlap approximately 25% of the logarithmic layer. The three-dimensional roughness elements alter the pressure statistics significantly, compared to the corresponding smooth-wall flow, in both the inner and outer (core) regions of the channel. The direct consequence of roughness is an increased form drag, associated with more intense pressure fluctuations. However, it also alters the pressure fluctuations in the outer layer of the flow, and modifies the length scales defined by two-point correlations. We also find that the depth of the roughness sublayer defined by the pressure fluctuations is very different from that given by the large- and small-scale statistics from the velocity field.
turbulence, rough-wall boundary layers, direct numerical simulation
028103-[4pp]
Bhaganagar, Kiran
cbcf27e1-3bdb-4e6a-ae1d-6f3d47dc5541
Coleman, Gary
ea3639b9-c533-40d7-9edc-3c61246b06e0
Kim, John
6ef2ee34-636c-4183-b129-d3a45f9839fc
February 2007
Bhaganagar, Kiran
cbcf27e1-3bdb-4e6a-ae1d-6f3d47dc5541
Coleman, Gary
ea3639b9-c533-40d7-9edc-3c61246b06e0
Kim, John
6ef2ee34-636c-4183-b129-d3a45f9839fc
Bhaganagar, Kiran, Coleman, Gary and Kim, John
(2007)
Effect of roughness on pressure fluctuations in a turbulent channel flow.
Physics of Fluids, 19 (2), .
(doi:10.1063/1.2482883).
Abstract
Direct numerical simulation is used to investigate the nature of pressure fluctuations induced by surface roughness in a turbulent channel flow at Re_\tau =400 for three-dimensional periodic roughness elements, whose peaks overlap approximately 25% of the logarithmic layer. The three-dimensional roughness elements alter the pressure statistics significantly, compared to the corresponding smooth-wall flow, in both the inner and outer (core) regions of the channel. The direct consequence of roughness is an increased form drag, associated with more intense pressure fluctuations. However, it also alters the pressure fluctuations in the outer layer of the flow, and modifies the length scales defined by two-point correlations. We also find that the depth of the roughness sublayer defined by the pressure fluctuations is very different from that given by the large- and small-scale statistics from the velocity field.
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effect_of_roughness_on_pressure_fluctuations_in_a_turbulent_channel_flow.pdf
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Published date: February 2007
Keywords:
turbulence, rough-wall boundary layers, direct numerical simulation
Organisations:
Aerodynamics & Flight Mechanics
Identifiers
Local EPrints ID: 44186
URI: http://eprints.soton.ac.uk/id/eprint/44186
ISSN: 1070-6631
PURE UUID: c1512c04-db7c-477e-a80c-da0e920eb07e
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Date deposited: 01 Mar 2007
Last modified: 15 Mar 2024 09:01
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Author:
Kiran Bhaganagar
Author:
Gary Coleman
Author:
John Kim
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