# CFD DATABASE

## 2D flow around a heated square-cylinder - $Re_{h}= 50$, $Ra= 5\; 10^6$

A heated square-cylinder is placed in a channel flow

Author : Y. Fraigneau CNRS-LIMSI (yann.fraigneau@lisn.fr)
Date : June 2019
Simulation type : DNS (Sunfluidh code)
Location : /DATABASE_2DFLOW_AROUND_HEATED_SQUARECYLINDER_DNS
Status : Free access
Data size : ~ 3 Gb

### Simulation settings

#### Referential : cartesian geometry

1. axes :
• x(i) : downstream direction
• y(j) : normal direction
2. origin : lower left corner of the computational domain
• $x_0= 10h$
• $y_0= -6h$

#### Reference scales

• Density : mass density of the fluid ($\rho_0$)
• Lengths : cylinder size ($h$) and $H_u= 10h$ the distance between the domain's top and the square-cylinder's top.
• Velocity : velocity at inlet ($U_0$)
• Dynamic viscosity : dynamic viscosity of the fluid ($\mu_0$)
• thermal diffusivity : ($\kappa_0$)
• Reynolds number : $Re_H= \frac{\rho_0.U_0.h}{\mu_0}= 50$
• Rayleigh number : $Ra= \frac{\rho_0.\beta.g\Delta T.H_u^3}{\mu_0 \kappa_0}= 5\;10^6$

#### Non-dimensionalised data

• velocity : $U^*=\frac{U}{U_0}$
• density : $\rho^*= \rho/\rho_0= 1$
• coordinates : $x*=\frac{x}{h}$, $y^*=\frac{y}{h}$
• temperature : $T^*=\frac{T-T_c}{T_h-T_c}$ ($T_h$ and $T_c$ are respectively the temperature imposed at the cylender's walls and the temperature at the inlet and channel's walls)

#### Computational domain

1. Domain scope
1. computational domain size (channel flow)
• Downstream direction(x) : $L_x^*= 50.0$ (upward part $L_u= -10$, downward part $L_d=40$)
• Normal direction (y) : $H*= 20.0$
2. heated square cylinder
• size: $h^*= 1$
• wall temperature T_h^*= 1
1. Boundary conditions
• Inlet : imposed pressure uniform velocity ($U_0=1$)
• Outlet : Orlansky type
• Bottom and top conditions : walls at (T_c^*=0)
2. Spatial resolution
• mesh size : $512 \times 256$ (131.072 cells)
• $\Delta x*$ : from $0.03125$ to $0.723$ (downstream direction)
• $\Delta y*$ : from $0.03125$ to $0.187$ (normal direction)

### Data features

• Time series
• Physical quantities : velocity components along x and y directions (u,v) and pressure (p)
• 1 probe
• Time step= $\approx 6 \,10^{-2}$ time unit (irregular time step)
• Time range : 250 time units
• Location : Xi= 20.0 , Xj=2.0
• File name (per physical quantity): x_ins_00000.d with x= u,v,t
• 3D snapshots
• Instantaneous fields : velocity components in x, y and z directions (U,V), the pressure (P) and the phase function related to the body motion (TRACE)
• Recording rate : 1 time unit
• Time range from from 20.0 to 250.0 time units
• File name : res_xxxxx_yyyyyyy.d
• MPI subdomain ID: from 0 to 3 (case with MPI domain decomposition)
• Time ID : from 0 to 250

### Database organisation

Data size : ~ 3 Gb
Main directory : /vol/DATABASE_MECA/DATABASE_2DFLOW_HEATED_SQUARRECYLINDER_DNS

Directories & files


/DATASETUP       : ASCII files
input data file for sunfluidh : input3d.dat (and input3d.dat_mpi4 for the case with MPI domain decomposition)

/GRID            : ASCII files
input data file         : data_meshgen.d
grid files for sunfluidh: maillx.d, mailly.d, maillz.d (sequential case)
mesh.tar (archive containing grid files for a domain decomposition with 4 MPI processes)

/SNAPSHOTS       : snapshots binary files res_xxxxx_yyyyyyy.d
/SNAPSHOTS_MPI4  : snapshots resulting from a domain decomposition with 4 MPI processes

/TIMESERIES      : ASCII files
u_ins_00000.d , v_ins_00000.d and t_ins_00000.d (timeseries of the velocity components and temperature from probe)
datasetmeca/flow2dpastheadtedcylinder1.txt · Dernière modification : 2022/01/04 18:12 de yann 