Index of /turbdata/blayers/high_re/fields

	Name	Last modified	Size	Description
	Parent Directory		-
	field_database_bitto..>	2014-01-30 20:58	-
	sample_field_direct_..>	2014-05-23 14:14	-
	sketch_grid_DNS.pdf	2014-06-07 19:36	151K

=======================================================================
            INFORMATION ABOUT THE DNS DATABASE
	    	     (HDF5 FILES)
=======================================================================

This directory tree contain some of the restart files of a direct 
numerical simulations of fully developed ZPG Boundary Layer flow 
(Re_theta=2780-6650) together with a sample matlab subroutine 
to read the files. Details are offered below.

The algorithm used is presented in: 

- M. P. Simens, J. Jimenez, S. Hoyas, Y. Mizuno
  "A high-resolution code for turbulent boundary layers"
  Journal of Computational Physics
  Volume 228, Issue 11, 20 June 2009, Pages 4218-4231 

- G. Borrell, J.A. Sillero, J. Jimenez 
  "A code for direct numerical simulation of turbulent boundary layers  
  at high Reynolds numbers in BG/P supercomputers" 
  Computers & Fluids, Volume 80, 10 July 2013, Pages 37-43 


The data is discussed in:

- J.A. Sillero, J. Jimenez, R.D. Moser 
  "One-point statistics for turbulent wall-bounded flows at Reynolds 
  numbers up to \delta^+\approx2000"  
  Phys. Fluids 25, 105102 


Directories:

./sample_field_direct_download/ : A single snapshot of the DNS hosted in our server
				  available to download using the "http" protocol.  
				  
./field_database_bittorrent/    : A collection of snapshots hosted somewhere else
				  available to download using the "BitTorrent" protocol.
				  
Further information is provided within each of these folders. 


-----------------------------------------------------------------------
                     STRUCTURE OF THE FILES:
-----------------------------------------------------------------------

The files are written in HDF5 format, which is supported by most of the 
mathematical programs. For programming languages, libraries can be 
downloaded for C, C++, Fortran 90, and Java interfaces.

The primitive variables {u,v,w,p} are stored in Fourier space as:
(kz,ny,nx) ---> ( Fourier - Physical -Physical )

For instance, one file contains:

 Re        Dataset {1}			: Inverse of the viscosity used in the code,
 	   	   			  which defines the scaling in which the code works.
 Variable  Dataset {SCALAR} 		: Variable recorded "u", "v", "w" or "p".
 procs     Dataset {536}	  	: Number of nodes used to run the simulation.
 	   	   			  (first element of the vector!)

 cfl       Dataset {1}	   		: Courant–Friedrichs–Lewy condition at which the
 	   	   			  simulation was run. 
 dt        Dataset {1}	   		: Time step in code units for this flow realization.
 tiempo    Dataset {1}	   		: Time stamp in code units for this flow realization.
 timeinit  Dataset {1}			: Initial time stamp in code units (=0).

 lx        Dataset {1}	   		: Defines the streamwise length Lx of the box, in code units.
 ly        Dataset {1}	   		: Defines the wall-normal length Ly of the box, in code units.
 lz        Dataset {1}	   		: Defines the spanwise length Lz of the box, in code units.
 nx        Dataset {1}	   		: Number of collocation points in the streamwise direction.
 ny        Dataset {1}	   		: Number of collocation points in the wall-normal direction.
 nz2       Dataset {1}	   		: Half the number of complex Fourier Gallerkin modes in z-> K_z[0:nz2]

We use the 2/3 dealiasing rule in z, so the number of collocation points in those directions are 3/2 
times the number of Fourier Gallerkin modes, and the extra modes are padded with zeroes. 
          	      	   			  

 xout      Dataset {1}	       		: Location of the recycling plane.
 um        Dataset {536}		: Mean streamwise velocity profile in code units at the recycling
 	   	   			  station "xout".
 y         Dataset {537}		: Non-uniform grid for the wall-normal distance; in code units.
 	   	   			  Note that, because of the staggered grid: y=(-y1,0,y1,y2,....)
 value     Dataset {15361, 536, 2730}	: Primitive variable in code units. The array is stored in single-precision
 	   	   	   		  as [1:2*(nz2+1),1:Ny,1:Nx], equivalent to the complex array [Kz,Ny,Nx]
					   

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 The sketch of the grid lay-out is specified in the .pdf file.  
---------------------------------------------------------------------------


 Before final publication of a paper citing these data, please check this
 site for an up-to-date reference.

 Please report any problems with the data, queries or doubts to J.A. Sillero, 
 sillero@torroja.dmt.upm.es