Dependence of Near-wall Flow on the Higher Moments of a Multi-scale Rough Surface

Jelly, T. , Sarakinos, S. and Busse, A. (2017) Dependence of Near-wall Flow on the Higher Moments of a Multi-scale Rough Surface. 70th Annual Meeting of the American Physical Society Division of Fluid Dynamics, Denver, CO, USA, 19-21 Nov 2017.

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Publisher's URL: http://meetings.aps.org/Meeting/DFD17/Session/Q24.8

Abstract

Fully developed turbulent channel flow past irregular multi-scale surface roughness has been investigated using direct numerical simulation (DNS) at a fixed friction Reynolds number of 395. The details of a surface generation algorithm --- which permits realistic rough surfaces to be synthesised with specified statistical properties for either experimental or computational studies --- will be outlined and discussed. The aim of the current work is to investigate the response of the near-wall region to systematic changes of higher order surface statistics, such as skewness and kurtosis. The influence of higher order moments is examined using double-averaged statistics of the turbulent flow which is decomposed into mean, dispersive and stochastic components. First-order roughness effects are investigated by quantifying the roughness function and examining the inner-scaled mean streamwise velocity profile. Second-order roughness effects are investigated by quantifying the relative magnitude of dispersive and Reynolds stresses in the near-wall region as a function of the surface skewness and kurtosis. Finally, modifications to the near-wall turbulence structure are examined by quantifying two-point velocity correlations for both the dispersive and stochastic components.

Item Type:Conference or Workshop Item
Status:Published
Refereed:No
Glasgow Author(s) Enlighten ID:Busse, Dr Angela and Sarakinos, Dr Sotirios and Jelly, Mr Thomas
Authors: Jelly, T., Sarakinos, S., and Busse, A.
College/School:College of Science and Engineering > School of Engineering > Aerospace Sciences
Copyright Holders:Copyright © 2017 American Physical Society
Publisher Policy:Reproduced in accordance with the publisher copyright policy

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Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
712071Fluid dynamic properties of irregular, multi-scale rough surfacesAngela BusseEngineering and Physical Sciences Research Council (EPSRC)EP/P004687/1ENG - AEROSPACE SCIENCES