Properties of d- and k-type roughness in a turbulent channel flow

Roughness is classified by the so-called roughness function, which represents the downward shift of the velocity profile relative to a smooth wall. The dependence of the roughness function on the Reynolds number is discussed with the aim of clarifying the difference between d-type and k-type behaviors. This difference has been traditionally associated with the stability of the flow within the roughness elements. The present direct numerical simulation results indicate that the difference more correctly reflects the different contributions from the frictional drag and pressure drag to the total stress.

[1]  Peter N. Joubert,et al.  Rough wall turbulent boundary layers , 1969, Journal of Fluid Mechanics.

[2]  T. G. Thomas,et al.  Mean Flow and Turbulence Statistics Over Groups of Urban-like Cubical Obstacles , 2006 .

[3]  I. Tani,et al.  Turbulent Boundary Layer Development over Rough Surfaces , 1987 .

[4]  Paolo Orlandi,et al.  Reynolds stress anisotropy of turbulent rough wall layers , 2002 .

[5]  Paolo Orlandi,et al.  Fluid Flow Phenomena , 2000 .

[6]  Paolo Orlandi,et al.  STRUCTURE OF TURBULENT CHANNEL FLOW WITH SQUARE BARS ON ONE WALL , 2004, Proceeding of Third Symposium on Turbulence and Shear Flow Phenomena.

[7]  S. Leonardi,et al.  Direct Numerical and Large-Eddy Simulations of Turbulent Flows over Rough Surfaces , 2006 .

[8]  Paolo Orlandi,et al.  Direct numerical simulations of turbulent channel flow with transverse square bars on one wall , 2003, Journal of Fluid Mechanics.

[9]  Promode R. Bandyopadhyay,et al.  Rough-wall turbulent boundary layers in the transition regime , 1987, Journal of Fluid Mechanics.

[10]  P. Orlandi,et al.  A method for determining the frictional velocity in a turbulent channel flow with roughness on the bottom wall , 2005 .

[11]  P. Durbin,et al.  Direct simulations of a rough-wall channel flow , 2007, Journal of Fluid Mechanics.

[12]  P. Jackson.  On the displacement height in the logarithmic velocity profile , 1981, Journal of Fluid Mechanics.

[13]  Tie Wei,et al.  Comment on the Clauser chart method for determining the friction velocity , 2005 .

[14]  P. Moin,et al.  Turbulence statistics in fully developed channel flow at low Reynolds number , 1987, Journal of Fluid Mechanics.

[15]  Paolo Orlandi,et al.  DNS of turbulent channel flows with two- and three-dimensional roughness , 2006 .

[16]  John Kim,et al.  DIRECT NUMERICAL SIMULATION OF TURBULENT CHANNEL FLOWS UP TO RE=590 , 1999 .

[17]  Zheng-Tong Xie,et al.  LES and RANS for Turbulent Flow over Arrays of Wall-Mounted Obstacles , 2006 .

[18]  Luciano Castillo,et al.  Zero-Pressure-Gradient Turbulent Boundary Layer , 1997 .

[19]  Paolo Orlandi,et al.  Turbulent channel flow with either transverse or longitudinal roughness elements on one wall , 2006, Journal of Fluid Mechanics.

[20]  Peter N. Joubert,et al.  Rough-wall boundary layers in adverse pressure gradients , 1963, Journal of Fluid Mechanics.

[21]  Paolo Orlandi,et al.  Fluid Flow Phenomena: A Numerical Toolkit , 1999 .

[22]  Peter Bradshaw,et al.  Perspectives in Turbulence Studies , 1987 .

[23]  R. A. Antonia,et al.  The turbulent boundary layer over transverse square cavities , 1999, Journal of Fluid Mechanics.