CFD DATABASE

Author : Y. Fraigneau CNRS-LIMSI (yann.fraigneau@limsi.fr)
Date : July 2016
Simulation type : DNS (Sunfluidh code)
Location : /DATABASE_2DFLOW_AROUND_OSCILLATING_CYLINDER_DNS
Status : Free access
Data size : ~ 7 Gb

A video is available here

Come back to first page

1. axes :
   • x(i) : downstream direction
   • y(j) : normal direction
2. origin :
   • $x_0= 0$ : centre of the cylinder
   • $y_0= 0$ : mid-height

• Density : mass density of the fluid ($\rho_0$)
• Length : cylinder diameter ($D$)
• Velocity : velocity at inlet ($U_0$)
• Dynamic viscosity : dynamic viscosity of the fluid ($\mu_0$)
• Reynolds number : $Re_H= \frac{\rho_0.U_0.D}{\mu_0}= 185$
• Strouhal number : $St_0=\frac{f}{f_0}$ (oscillating-cylinder frequency $f$ over vortex-shedding frequency $f_0$ when the cylinder is at rest)
• motion magnitude : $A \times D$ (where A is the motion factor)

• velocity : $U^*=\frac{U}{U_0}$
• density : $\rho^*= \rho/\rho_0= 1$
• coordinates : $x*=\frac{x}{D}$, $y^*=\frac{y}{D}$

1. Domain scope
   1. computational domain size
      • Downstream direction(x) : $L_x^*= 90.0$ (upward part $L_u= 40$, downward part $L_d=50$)
      • Normal direction (y) : $L_y^*= 80.0$
   2. Oscillating cylinder (vertical oscillating motion around the mid-height of the domain)
      • centre position at rest : $x_c= 0.0$ and $y_c= 0.0$
      • diameter: $D^*= 1$
      • oscillation frequency : $St= 0.95$ or $St= 1.2$
      • The cylinder is modeled with a pseudo-penalisation method (Pasquetti et al., Applied Numerical Mathematics, 2008)
2. Boundary conditions
   • Inlet : imposed pressure uniform velocity ($U_0=1$)
   • Outlet : Orlansky type
   • Bottom and top conditions : symmetry
3. Spatial resolution
   • mesh size : $480 \times 480 $ (576.000 cells)
   • About cell-size
     • $\Delta x*$ : from $0.0125$ to $0.78785$$ (downstream direction)
     • $\Delta y*$ : from $0.0125$ to $0.65924$ (normal direction)

Come back to first page

• Time series
  • from probes
    • Physical quantities : velocity components along x and y directions (u,v) and pressure (p)
    • 1 probe
    • Time step= $2 \,10^{-2}$ time unit
    • Time range : 400 to 600 time units
    • Location : Xi= 3.5 , Xj=0.0
    • File name (per physical quantity): x_ins_00000.d with x= u,v,p
  • about cylinder motion
    • center position as a function of time (ASCII file ibm_position01.dat)
    • cylinder velocity as a function of time (ASCII file ibm_velocity01.dat)
    • global force components applied to the cylinder (ASCII file ibm_force01.dat)
    • force contributions exerted on the moving cylinder (ASCII file ibm_force_contribution01.dat, the four last columns can be ignored)

• 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 : 0.4 time unit
  • Time range from from 200.0 to 600.0 time units
  • File name : res_xxxxx_yyyyyyy.d
    • MPI subdomain ID: 0
    • Time ID : from 3 to 502

Come back to first page

Data size : ~ 7 Gb
Main directory : /vol/DATABASE_MECA/DATABASE_2DFLOW_AROUND_OSCILLATING_CYLINDER_DNS
For more details about files, see the wiki doc of Sunfluidh

Intermediate directories (four cases of study)

• $St= 0.95$ and $A= 0.2$ - directory : CAS_F0.95_A0.2
• $St= 0.95$ and $A= 0.5$ - directory : CAS_F0.95_A0.5
• $St= 1.20$ and $A= 0.2$ - directory : CAS_F1.2_A0.2
• $St= 1.20$ and $A= 0.5$ - directory : CAS_F1.2_A0.5

Endpoint directories & files

                               
  /DATASETUP       : ASCII files
                     input data file for sunfluidh : input3d.dat
  
  /GRID            : ASCII files
                     input data file         : data_meshgen.d
                     grid files for sunfluidh: maillx.d, mailly.d, maillz.d
   
  /SNAPSHOTS       : snapshots binary files res_xxxxx_yyyyyyy.d
  
  /TIMESERIES      : ASCII files
                     u_ins_00000.d , v_ins_00000.d and p_ins_00000.d (timeseries of the velocity components and pressure from probe)
                     ibm_position01.dat, ibm_velocity01.dat (about cylinder motion)
                     ibm_force01.dat, ibm_force_contribution01.dat (about forces exerted on the cylinder)
                     
               

Come back to first page