Vortex structure of turbulence over permeable walls

In order to understand the effect of the wall permeability on the turbulent vortex structure near porous walls, based on PIV experimental data, a probability density analysis of fluctuating velocities, statistical quadrant and quadrant-hole analyses of the Reynolds shear stress are performed. The investigated flow fields are turbulent channel flows whose bottom walls are made of porous media. The porous media used are three kinds of foamed ceramics which have almost the same porosity (∼0.8) but different permeability. From the discussions on those analyses, a conceptual scenario of the development of the vortex structure near a permeable wall is proposed for a moderate permeability Reynolds number case. It explains the reason why the near-wall long streaky structure tends to vanish near a porous wall with increasing wall permeability.

[1]  J. Finnigan.  Turbulence in plant canopies , 2000 .

[2]  F. A. Schraub,et al.  The structure of turbulent boundary layers , 1967, Journal of Fluid Mechanics.

[3]  James M. Wallace,et al.  The wall region in turbulent shear flow , 1972, Journal of Fluid Mechanics.

[4]  K. Suga,et al.  Simultaneous measurement of turbulent velocity field and surface wave amplitude in the initial stage of an open-channel flow by PIV , 2005 .

[5]  Ronald J. Adrian,et al.  Spanwise structure and scale growth in turbulent boundary layers , 2003, Journal of Fluid Mechanics.

[6]  R. A. Antonia,et al.  Conditional Sampling in Turbulence Measurement , 1981 .

[7]  C. Willert,et al.  Digital particle image velocimetry , 1991 .

[8]  A. Ferrero,et al.  Measurement uncertainty , 2006, IEEE Instrumentation & Measurement Magazine.

[9]  Massoud Kaviany,et al.  Slip and no-slip velocity boundary conditions at interface of porous, plain media , 1992 .

[10]  J. A. Schetz,et al.  Turbulent boundary layer over porous surfaces with different surface geometries , 1982 .

[11]  Stephen Whitaker,et al.  Momentum transfer at the boundary between a porous medium and a homogeneous fluid-I. Theoretical development , 1995 .

[12]  R. Adrian,et al.  Effect of resolution on the speed and accuracy of particle image velocimetry interrogation , 1992 .

[13]  R. P. Benedict,et al.  ASME Measurement Uncertainty , 1985 .

[14]  M. Raupach,et al.  Conditional statistics of Reynolds stress in rough-wall and smooth-wall turbulent boundary layers , 1981, Journal of Fluid Mechanics.

[15]  J. Katz,et al.  PIV measurements in the atmospheric boundary layer within and above a mature corn canopy. Part II Quadrant-hole analysis , 2007 .

[16]  S. K. Robinson,et al.  Coherent Motions in the Turbulent Boundary Layer , 1991 .

[17]  K. Suga,et al.  Effects of wall permeability on turbulence , 2010 .

[18]  R. A. Antonia,et al.  Rough-Wall Turbulent Boundary Layers , 1991 .

[19]  Carl D. Meinhart,et al.  Vortex organization in the outer region of the turbulent boundary layer , 2000, Journal of Fluid Mechanics.

[20]  A. K. Gupta,et al.  Spatial structure in the viscous sublayer , 1971, Journal of Fluid Mechanics.

[21]  Stephen J. Kline,et al.  The production of turbulence near a smooth wall in a turbulent boundary layer , 1971, Journal of Fluid Mechanics.

[22]  W. Graf,et al.  TURBULENT BOUNDARY-LAYER FLOW OVER PERMEABLE AND NON-PERMEABLE ROUGH SURFACES , 1983 .

[23]  John F. Kennedy,et al.  FRICTION-FACTORS FOR FLAT-BED FLOWS IN SAND CHANNELS , 1969 .

[24]  Flow at the interface of a model fibrous porous medium , 2001, Journal of Fluid Mechanics.

[25]  Y. Nishio,et al.  Three Dimensional Microscopic Flow Simulation Across the Interface of a Porous Wall and Clear Fluid by the Lattice Boltzmann Method , 2009 .

[26]  Brian J. Cantwell,et al.  Organized Motion in Turbulent Flow , 1981 .

[27]  R. E. Uittenbogaard,et al.  The influence of wall permeability on turbulent channel flow , 2006, Journal of Fluid Mechanics.

[28]  Kenneth V. H. Smith,et al.  Channel Flow Over Permeable Beds of Graded Spheres , 1976 .

[29]  Suresh G. Advani,et al.  Flow near the permeable boundary of a porous medium: An experimental investigation using LDA , 1997 .

[30]  S. Vollmer,et al.  Micro scale exchange processes between surface and subsurface water , 2002 .

[31]  P. Moin,et al.  DIRECT NUMERICAL SIMULATION: A Tool in Turbulence Research , 1998 .

[32]  Kambiz Vafai,et al.  Analysis of fluid flow and heat transfer interfacial conditions between a porous medium and a fluid layer , 2001 .

[33]  N. Rudraiah.  Coupled Parallel Flows in a Channel and a Bounding Porous Medium of Finite Thickness , 1985 .

[34]  Costantino Manes,et al.  Velocity Measurements of a Free-Surface Turbulent Flow Penetrating a Porous Medium Composed of Uniform-Size Spheres , 2009 .

[35]  W. Willmarth,et al.  Structure of the Reynolds stress near the wall , 1972, Journal of Fluid Mechanics.

[36]  P. Moin,et al.  Direct numerical simulation of turbulence in a nominally zero-pressure-gradient flat-plate boundary layer , 2009, Journal of Fluid Mechanics.

[37]  D. Joseph,et al.  Boundary conditions at a naturally permeable wall , 1967, Journal of Fluid Mechanics.