Simulation of large-eddy-break-up device (LEBU) in a moderate Reynolds number turbulent boundary layer

Authors: Chin, C., Monty, J., Hutchins, N., Ooi, A., Örlü, R., Schlatter, P.
Document Type: Conference
Pubstate: Published
Journal: Proc. 9th Turbulence Shear Flow Phenomena (TSFP-9), June 30 - July 3, 2015, The University of Melbourne, Australia
Volume: 1  
Year: 2015


A well-resolved large eddy simulation (LES) of a large-eddy break-up (LEBU) device in a spatially evolving turbulent boundary layer up to Re? ? 4300 is performed. The LEBU is a flat plate that is implemented via an immersed boundary method. Initial flow visualizations show successful implementation of the LEBU. The LEBU is lo- cated at a wall-normal distance of 0.8? (local boundary layer thickness) from the wall and acts to delay the growth of the turbulent boundary layer. The LEBU serves to reduce skin friction drag up to 160? downstream of the LEBU but no net drag reduction is found. Investigation is performed on the interactions of high and low momentum bulges with the LEBU and the corresponding output is analysed, showing a ‘break-up’ of these large momentum bulges. In addition, results show an attenuated turbulence intensity profile downstream of the LEBU, which is mainly due to a reduction in energy at spanwise length scales of ?z+ < 200 and > 500. http://www.tsfp-conference.org/proceedings/2015/v1/1A-3.pdf