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datasetmeca:bfsflow_1

3D backward-facing step flow at $Re_H= 6000$

Author : Y. Fraigneau CNRS-LIMSI (yann.fraigneau@limsi.fr)
Date : August 2018
Simulation type : DNS (Sunfluidh code)
Location : DATABASE_BACKWARDFACINGSTEPFLOW_RE6000_DNS
Status : Restricted access
Data size : ~ 4.4 Tb


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Simulation settings


2D sketch

Referential : cartesian geometry

  1. axes :
    • x(i) : downstream direction
    • y(j) : normal direction
    • z(k) : spanwise direction
  2. origin :
    • $x_0= 0$ : the step
    • $y_0= 0$ : the bottom wall of the domain
    • $z_0= 0$ : the left side of the computational domain

Reference scales

  • Density : mass density of the fluid ($\rho_0$)
  • Length : step height ($H$)
  • Velocity : inlet bulk velocity ($U_i$)
  • Dynamic viscosity : dynamic viscosity of the fluid ($\mu_0$)
  • Reynolds number : $Re_H= \frac{\rho_0.U_i.H}{\mu_0}= 6000$

Non-dimensionalised data

  • velocity : $U^*=\frac{U}{U_i}$
  • density : $\rho^*= \rho/\rho_0= 1$
  • coordinates : $x*=\frac{x}{H}$, $y^*=\frac{y}{H}$ , $z^*=\frac{z}{H}$

Computational domain

  1. Domain scope
    • Downstream direction(x) : $L^*= 36.0$
    • Normal direction (y) : $H_t^*= 2.0$
    • Spanwise direction (z) : $l^*= 2\pi$
    • Step position : $L_s^*= 12.0$
    • Step height : $H^*= 1$
  2. Boundary conditions
    • Inlet : Uniform profile at $X_{in}^*= -12.0$
    • Outlet : Orlansky's type at $X_{out}^*= 24.0$
    • Wall conditions : Top and low walls of the domain
    • Periodicity : lateral ends of the domain
  3. Domain decomposition (160 MPI subdomains)
    • Along the downstream direction :
      • 12 (between the inlet and the outlet, above the step)
      • 8 (between the step and the outlet)
    • Along the normal direction : 4
    • Along the spanwise direction : 4
    • 2D sketch of domain decomposition in a plan {xy} (MPI process distribution (1))
      1 1 1 1 1 1 1 1 1 1 1 1
      1 1 1 1 1 1 1 1 1 1 1 1
      0 0 0 0 1 1 1 1 1 1 1 1
      0 0 0 0 1 1 1 1 1 1 1 1
  4. Spatial resolution :
    • Grid : $128 \times 64 \times 64$ per subdomain (83.886.080 cells over the domain)
    • About cell-size
      • $\Delta x_{min}^*= 1.0 \, 10^{-3} \quad \Delta x_{max}^*= 2.456 \,10^{-2}$ (downstream direction)
      • $\Delta y_{min}^*= 1.1 \, 10^{-3} \quad \Delta y_{max}^*= 1.653 \,10^{-2}$ (normal direction)
      • $\Delta z_{min}^*=\Delta z_{max}^*= 2.4543 \, 10^{-3}$ (spanwise direction)

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Data features


  • Time series from probes
    • Physical quantities : velocity components along x, y and z directions (u,v,w) and pressure (p)
    • 11 probes
    • Time step= 0.01 time unit
    • Time range : 200.0 to 513.3 time units
    • Locations (In vertical plan at $z=3.14$)
      • Xi=-4.00 , Xj= 1.50 , Xk= 3.14 - MPI Subdomain ID : 17
      • Xi=-2.00 , Xj= 1.50 , Xk= 3.14 - MPI Subdomain ID : 25
      • Xi= 0.10 , Xj= 1.00 , Xk= 3.14 - MPI Subdomain ID : 37
      • Xi= 4.00 , Xj= 1.00 , Xk= 3.14 - MPI Subdomain ID : 53
      • Xi= 4.00 , Xj= 0.01 , Xk= 3.14 - MPI Subdomain ID : 49
      • Xi= 6.00 , Xj= 1.00 , Xk= 3.14 - MPI Subdomain ID : 69
      • Xi= 6.00 , Xj= 0.01 , Xk= 3.14 - MPI Subdomain ID : 65
      • Xi= 8.00 , Xj= 1.00 , Xk= 3.14 - MPI Subdomain ID : 69
      • Xi= 8.00 , Xj= 0.01 , Xk= 3.14 - MPI Subdomain ID : 65
      • Xi=16.0 , Xj= 1.00 , Xk= 3.14 - MPI Subdomain ID : 117
      • Xi=16.0 , Xj= 0.01 , Xk= 3.14 - MPI Subdomain ID : 113
    • File name (per physical quantity) : x_ins_yyyyy.d with x= u,v,w,p and 'yyyyy' the MPI subdomain ID
  • 3D snapshots
    • Instantaneous fields : velocity components in x, y and z directions (U,V,W) and pressure (P)
    • Recording rate : 0.1 time unit
    • Time range from from 185.3 to 513.3 time units
    • File name : res_xxxxx_yyyyyyy.d (xxxxx : MPI subdomain ID, yyyyyyy : Time ID)
      • MPI subdomain ID: from 0 to 159
      • Time ID : from 186 to 3465
  • Statistics
    • fields : (i,j : indexes of direction x, y or z)
      • Mean fields of velocity components (<Ui>) and pressure (<P>)
      • Mean fields of quadratic quantities (<P2>, <UiUj>)
    • Time and space average computation (along the spanwise direction)
    • Time startup = 180.0 time units
    • Time range per file = 10.0 time units
    • Total time range from 180.0 to 510.0 time units
    • file name : rst_xxxxx_yyyyyyy.d (xxxxx : MPI subdomain ID, yyyyyyy : Time ID)
      • MPI subdomain ID : from 0 to 39 (MPI process rank where results about space average computation are stored)
      • Time ID : from 1 to 33

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Database organisation


Data size : ~ 4.4 Tb
Main directory : /vol/DATABASE_MECA/RESTRICTED_ACCESS/DATABASE_BACKFACINGSTEPFLOW_RE6000_DNS
For more details about files, see the wiki doc of Sunfluidh

Directories & files

  /GRID : contains all ASCII files about grid setup
  
     input data file         : data_meshgen.d
     report on grid features : report_meshgen.d
     grid files for sunfluidh: maillx.d, mailly.d, maillz.d
     check files (ASCII)     : check_mesh_I.d,check_mesh_J.d,check_mesh_K.d
                               (3 columns : indices, cell-face coordinates, cell size)
                               
  /DATASETUP       : ASCII files
   
   input data file for sunfluidh : input3d.dat
   data file for MPI subdomain distribution (MPI graphical topology): data_mpi_subdomain_layout.dat
  
  /TIMESERIES : contains time series recorded over the time range [200,513.3]
                ASCII files : x_ins_yyyyy.d   with x= u,v,w,p
                time series files are sliced in directories CAS-MPI160-n (n from 121 to 330)
                WARNING : possible underlying of time series for these data couples :
                           n = (243,244)
                           n = (246,247)
                           n = (259,260)
                           n = (260-261)
   
                           The directory CAS-MPI160-260 contains 2 groups of
                           consecutive timeseries files placed in directories DIR-A and DIR-B
   
  /SNAPSHOTS  : snapshots binary files res_xxxxx_yyyyyyy.d
                files stored in archive files : res_yyyyyyy.tar for each time ID
               
  /STATISTICS : statistics binary files files rst_xxxxx_yyyyyyy.d
                files stored in archive files : rst_z.tar , z is an ID number
               
  /RESTART_AR : backup/restart archive save.tar at 513.27 time units
  

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datasetmeca/bfsflow_1.txt · Dernière modification: 2020/11/23 18:10 de yann