CFD DATABASE

Author : Y. Fraigneau CNRS-LIMSI (yann.fraigneau@lisn.fr)
Date : August 2020
Simulation type : DNS (Sunfluidh code)
Location : DATABASE_FORWARDFACINGSTEPFLOW2_RE8000_DNS
Status : Restricted access
Data size : ~ 5.2 Tb

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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

• 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 : $Re_H= \frac{\rho_0.U_0.H}{\mu_0}= 8000$

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

1. Domain scope
   • Downstream direction(x) : $L^*= 37.0$
   • Normal direction (y) : $H_t^*= 22.0$
   • Spanwise direction (z) : $l^*= \pi$
   • Step position : $L_s^*= 17.0$
   • Step height : $H^*= 1$
2. Boundary conditions
   • Inlet : Turbulent boundary layer at $X_{in}^*= -17.0$, $\delta_{in}= \frac{H}{3}$ (boundary layer's thickness)
     $Re_{\theta}=300$, fluctuations generated from the SEM approach.
   • Outlet : Orlansky's type at $X_{out}^*= 20.0$
   • Wall conditions : Top and low walls of the domain
   • Periodicity : lateral ends of the domain
3. Domain decomposition (200 MPI subdomains)
   • Along the downstream direction :
     • 15 (between the inlet and the outlet, above the step)
     • 10 (between the inlet and the step)
   • 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 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 1 0 0 0 0 0 0 0 0 0 0
     
4. Spatial resolution
   • Grid : $128 \times 192 \times 96$ per subdomain (471.859.200 cells over the domain)
   • About cell-size
     • $\Delta x_{min}^*= 1.0 \, 10^{-2} \quad \Delta x_{max}^*= 2.5 \,10^{-2}$ (downstream direction)
     • $\Delta y_{min}^*= 1.5 \, 10^{-3} \quad \Delta y_{max}^*= 7.5 \,10^{-2}$ (normal direction)
     • $\Delta z_{min}^*=\Delta z_{max}^*= 8.18123 \, 10^{-3}$ (spanwise direction)

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• Time series from probes : U,V,W,P (velocity components & pressure)
  • Physical quantities : velocity components along x, y and z directions (u,v,w) and pressure (p)
  • 5 probes
  • Time step= 0.0126 time unit
  • Time range : 188.37 to 396.87 time units
  • Locations (In vertical plan at $z=1.57$)
    • Xi=-0.250 , Xj= 0.250 , Xk= 1.57 - MPI Subdomain ID :
    • Xi= 0.125 , Xj= 1.125 , Xk= 1.57 - MPI Subdomain ID :
    • Xi= 1.000 , Xj= 1.125 , Xk= 1.57 - MPI Subdomain ID :
    • Xi= 1.000 , Xj= 1.250 , Xk= 1.57 - MPI Subdomain ID :
    • Xi= 4.000 , Xj= 1.125 , Xk= 1.57 - MPI Subdomain ID :

• 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)
  • first dataset :
    • Recording rate : 0.9 time units
    • Time range from 189.877 to 303.877 time units
    • File name : res_xxxxx_yyyyyyy.d (xxxxx : MPI subdomain ID, yyyyyyy : Time ID)
      • MPI subdomain ID: from 0 to 199
      • Time ID : from 69 to 195
  • second dataset :
    • Recording rate : 0.3 time units
    • Time range from 303.877 to 396.877 time units
    • File name : res_xxxxx_yyyyyyy.d (xxxxx : MPI subdomain ID, yyyyyyy : Time ID)
      • MPI subdomain ID: from 196 to 199
      • Time ID : from 196 to 505

• 2D slices
  • Instantaneous fields : velocity components in x, y and z directions (U,V,W) and pressure (P)
  • Recording rate : 0.3 time units
  • Time range from from 189.877 to 396.877 time units
  • 3 slices are considered :
    • slice 1 : normal direction k - position : z= 1.57 - MPI subdomains ID :
      • MPI subdomains ID : 1 to 197 with a stride of 4
    • slice 2 : normal direction x - position : x=-0.01
      • MPI subdomains ID : 64 to 79
    • slice 3 : normal direction y - position : y= 1.30
      • MPI subdomains ID : 4 to 7
      • MPI subdomains ID : 20 to 23
      • MPI subdomains ID : 36 to 39
      • MPI subdomains ID : 52 to 55
      • MPI subdomains ID : 68 to 71
      • MPI subdomains ID : 80 to 83
      • MPI subdomains ID : 92 to 95
      • MPI subdomains ID :104 to 107
      • MPI subdomains ID :116 to 119
      • MPI subdomains ID :128 to 131
      • MPI subdomains ID :140 to 143
      • MPI subdomains ID :152 to 155
      • MPI subdomains ID :164 to 167
      • MPI subdomains ID :176 to 179
      • MPI subdomains ID :188 to 191
    • File name : slice_n_idir_xxxxx_yyyyyyy.d (n : slice number ID, idir : direction= 1: x(i), 2: y(j), 3: z(k), xxxxx : MPI subdomain ID, yyyyyyy : Time ID)
      • MPI subdomain ID: ??
      • Time ID : from 748 to ??

• 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 = 200.0 time units
  • Time range per file = 10.0 time units
  • Total time range from 200.0 to 390 time units
  • file name : rst_xxxxx_yyyyyyy.d (xxxxx : MPI subdomain ID, yyyyyyy : Time ID)
    • MPI subdomain ID : from 0 to 49 (MPI process rank where results about space average computation are stored)
    • Time ID : from 1 to 19

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Data size : ~ 3.2 Tb
Main directory : /vol/DATABASE_MECA/RESTRICTED_ACCESS/DATABASE_BACKFACINGSTEPFLOW_RE6000_DNS
For more details about files, see the the wiki doc of Sunfluidh

  /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 [188.37,??]
                  ASCII files : x_ins_yyyyy.d   with x= u,v,w,p
                  time series files are sliced in storage directories CAS-MPI200-n (n from 130 to ??)
   
  /SNAPSHOTS    : snapshots binary files res_xxxxx_yyyyyyy.d with a recording rate of 0.9 time unit
                  files stored in archive files : res_yyyyyyy.tar for each time ID
                
  /SNAPSHOTS_FS : snapshots binary files res_xxxxx_yyyyyyy.d with a recording rate of 0.3 time unit
                  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 : res_z.tar , z is an ID number (from 1 to ??)
                
  /SLICES       : slice binary files slice_n_idir_xxxxx_yyyyyyy.d
                  files stored in archive files : slices_z.tar , z is an ID number (from 131 to ??)
               
  /RESTART_AR   : backup/restart archive save.tar at time ??
  

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