CFD DATABASE

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===== 3D forward-facing step flow at $Re_H= 8304$ (turbulent inflow) =====

<note info>
**Database in progress ... it is currently uncompleted**
</note>

**Author** :  Y. Fraigneau, LISN, UMR CNRS 9015 (yann.fraigneau@lisn.fr) \\
**Date**   :  August 2020\\
**Simulation type** : DNS (code Sunfluidh -- [[https://sunfluidh.lisn.upsaclay.fr|Sunfluidh code]]) \\
**Location** : DATABASE_FORWARDFACINGSTEPFLOW2_RE8000_DNS   \\
**Status** : Restricted access \\
**Data size** : ~ 8.6 Tb \\


{{ :flowstructure_ffs_turb_pview.png?900 |}}

\\
[[https://sunfluidh.lisn.upsaclay.fr/doku.php?id=sunfluidh:sunfluidh_gallery]| A video is available here ]]
\\

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==== Simulation settings ====
----

=== 2D sketch ===

{{ :datasetmeca:sketch_ffs_turb.jpg?600 |}}


=== Referential : cartesian geometry ===
   - axes   :
      * x(i) : downstream direction
      * y(j) : normal direction
      * z(k) : spanwise direction
    - 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 : $Re_H= \frac{\rho_0.U_0.H}{\mu_0}= 8304$

=== 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 ===

   - **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    : $H^*= 1$
  - **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
  - ** 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 \\
  - **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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==== Data features ====
----

   * **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= 0.00945 time unit
      * Time range : from 120 to 700 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 : **0.5** time units
             * Time range from 120 to 729 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 53 to 1270
        
   * **2D slices** 
         * Instantaneous fields : velocity components in x, y and z directions (U,V,W) and pressure (P)
         * Recording rate : **0.1** time units 
         * Time range from 120 to 729 time units
         * 4 slices are considered :
           * slice 1 : normal direction z - position : z= 1.57 - MPI subdomains ID :
                 * MPI subdomains ID :  1 to  197
           * slices 4,5,6 : Wall pressure only
                *  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)
                 * slice 4 : normal direction y - position : y= 0.0 **WARNING : available only from Time ID = 139 (corresponding to time > 386)**
                 * slice 5 : normal direction x - position : x= 0.0
                 * slice 6 : normal direction y - position : y= 1.0
                 * 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
                 * Time ID : from 54 to 6363

   * **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        = 100.0 time units
      * Time range per file = 20.0 time units
      * Total time range    from  100.0  to 720 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 31

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==== Database organisation ====
----

**Data size** : ~ 8.6 Tb \\
**Main directory** : /vol/DATABASE_MECA/RESTRICTED_ACCESS/DATABASE_FORWARDFACINGSTEPFLOW2_RE8000_DNS \\
For more details about files, see the [[https://sunfluidh.limsi.fr|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 [120,680]
                    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 53 to 255)
     
    /SNAPSHOTS    : snapshots binary files res_xxxxx_yyyyyyy.d with a recording rate of 0.5 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 31)
                  
    /SLICES       : slice binary files slice_n_idir_xxxxx_yyyyyyy.d
                    files stored in archive files : slices_z.tar , z is an ID number (from 53 to 255)
                 
    /RESTART_AR   : backup/restart archive save_t145.tar and save_t45.tar at time=145 and 454 respectively 
    

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