Author : Y. Fraigneau, LISN, UMR CNRS 9015 (yann.fraigneau@lisn.fr)
Date : July 2018
Simulation type : DNS (code Sunfluidh Sunfluidh code)
Location : DATABASE_AHMEDBODY_RE10000_DNS
Status : Restricted access
Data size : ~ 609 Gb

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1. axes :
   • x : downstream direction
   • y : normal direction
   • z : spanwise direction
2. origin :
   • $x_0= 0$ : upstream edge of Ahmed body top
   • $y_0= 0$ : Ahmed body top
   • $z_0= 0$ : mid-span of domain

• Density : mass density of the fluid ($\rho_0$)
• Length : Ahmed body height ($H$)
• Velocity : inlet bulk velocity ($U_0$)
• Dynamic viscosity : dynamic viscosity of the fluid ($\mu_0$)
• Reynolds number : $Re_H= \frac{\rho_0.U_0.H}{\mu_0}= 10000$

• velocity : $U^*=\frac{U}{U_0}$
• 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) : $L_t^*= 10.5$
   • Normal direction (y) : $H_t^*= 2.5$
   • Spanwise direction (z) : $W_t^*= 3.718$
   • Ahmed body size : $L^*\times W^*\times H^* = 3.784 \times 1.178 \times 1$
   • Quarter rounded edges radius around the front face of the body : $R^*=0.347$
   • Ground clearance : $Hg^*= 0.334$
2. Boundary conditions
   • Inlet : Uniform profile at $X_{in}^*= -1.0$
   • Outlet : Orlansky's type at $X_{out}^*= 9.5$
   • Wall conditions : Ahmed body, top and low walls of the domain
   • Symmetry : lateral ends of the domain
3. Spatial resolution :
   • Grid : $512 \times 256 \times 256$ (33.554.432 cells)
   • About cell-size
     • $\Delta x_{min}^*= 1 \, 10^{-2} \quad \Delta x_{max}^*= 3.03588 \,10^{-2}$ (downstream direction)
     • $\Delta y_{min}^*= 2 \, 10^{-3} \quad \Delta y_{max}^*= 4.12564 \,10^{-2}$ (normal direction)
     • $\Delta z_{min}^*= 2 \, 10^{-3} \quad \Delta z_{max}^*= 4.59486 \,10^{-2}$ (spanwise direction)

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• Time series from probes
  • Physical quantities : velocity components along x, y and z directions (u,v,w) and pressure (p)
  • 3 probes
  • Time step= $5.5 \,10^{-3}$ time unit
  • Time range : 71 to 303, 343 to 680, 680 to 729, 729 to 780 time units
  • Locations (In horizontal mid-plan of the body wake)
    • Xi= 4.384 , Xj=-0.5 , Xk= 0.3
    • Xi= 4.384 , Xj=-0.5 , Xk= 0.0
    • Xi= 4.384 , Xj=-0.5 , Xk=-0.3
  • File name (per physical quantity): x_ins_00000.d with x= u,v,w,p

• 3D snapshots
  • Instantaneous fields : velocity components along x,y and z directions (U,V,W) and pressure (P)
  • Recording rate : 0.5 time unit
  • Time range from from 185 to 780 time units
  • File name : res_xxxxx_yyyyyyy.d (xxxxx : MPI subdomain ID, yyyyyyy : Time ID)
    • MPI subdomain ID= 0 (No domain decomposition)
    • Time ID : 178 to 1364

• 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 startup = 43 time units
  • Time range per file = 10 time units
  • Total time range from 43 to 780 time units
  • file name : rst_xxxxx_yyyyyyy.d (xxxxx : MPI subdomain ID, yyyyyyy : Time ID)
    • MPI subdomain ID= 0 (No domain decomposition)
    • Time ID : 1 to 73

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Data size : ~ 802 Gb
Main directory : /vol/DATABASE_MECA/RESTRICTED_ACCESS/DATABASE_AHMEDBODY_RE10000_DNS
For more details about files, see the wiki doc of Sunfluidh

  /GRID : contains all 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       : it contains input data file for sunfluidh : input3d.dat
  
  /TIMESERIES : contains time series recorded from probes
                /TIMESERIES_T071-305  : from time= 71 to 303 time units
                /TIMESERIES_T343-533  : from time=343 to 533 time units
                /TIMESERIES_T533-638  : from time=533 to 638 time units
                /TIMESERIES_T638-680  : from time=638 to 680 time units
                /TIMESERIES_T680-729  : from time=680 to 729 time units
                /TIMESERIES_T729-780  : from time=729 to 780 time units
                    ASCII files : x_ins_00000_full.d   with x= u,v,w,p
                    also contains the space-averaged kinetic energy from time=326 to 561 (time step : 2.55D-02)
                    ASCII file : space_averaged_ke.d
  
  /SNAPSHOTS  : snapshots binary files res_xxxxx_yyyyyyy.d
               
  /STATISTICS : statistics binary files rst_xxxxx_yyyyyyy.d
               
  /RESTART_AR : backup/restart archives save_t361.tar, save_t561.tar, save_t638.tar, save_t729.tar, save_t780.tar
                contains any file to resume the simulation at time = 361, 561, 638, 729 and 780 time units
  
  /FROM_COMPUTATION : regroup some directories and files related to the simulation
   
  /SLICES     : slices ... not documented  (old study)
                Binary files : plan_id_dir_xxxxx_yyyyyyy.d
               (nn : slice ID, dir : orientation, xxxxx : MPI subdomain ID, yyyyyyy : Time ID)

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