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

Author : Y. Fraigneau CNRS-LIMSI (yann.fraigneau@limsi.fr)
Date : August 2020
Location : DATABASE_BACKWARDFACINGSTEPFLOW_RE6000_DNS
Simulation type : DNS (Sunfluidh code)

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Simulation settings

Sketch

Referential : cartesian geometry

axes :

x(i) : downstream direction

y(j) : normal direction

z(k) : spanwise direction

origin :

: the step

: the bottom wall of the domain

: the left side of the computational domain

Reference scales

Density : mass density of the fluid ()

Length : step height ()

Velocity : inlet bulk velocity ()

Dynamic viscosity : dynamic viscosity of the fluid ()

Reynolds number :

Non-dimensionalised data

velocity :

density :

coordinates : , ,

Computational domain

Domain scope

Downstream direction(x) :

Normal direction (y) :

Spanwise direction (z) :

Step position :

Step height :

Boundary conditions

Inlet : Uniform profil at

Outlet : Orlansky's type at

Wall conditions : Top and low walls of the domain

Periodicity : lateral ends of the domain

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

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

Spatial resolution :

Grid : per subdomain (83.886.080 cells over the domain)

About cell-size

(downstream direction)

(normal direction)

(spanwise direction)

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Data Recording : information about data types

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 )

Xi=-4.00 , Xj= 1.50 , Xk= 3.14 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 square 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 To
Main directory : /vol/DATABASE_MECA/RESTRICTED_ACCESS/DATABASE_BACKFACINGSTEPFLOW_RE6000_DNS
For more details about files, see the 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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