This document lists all input parameters for the simulation, including types, default values, optional descriptions, and allowed values. Parameter names are highlighted as inline code.
Domain size
| Parameter |
Type |
Default Value |
Description / Notes |
Possible Values |
Lxp |
float |
2π |
Domain length in x-direction |
>0 |
Lzp |
float |
π |
Domain length in z-direction |
>0 |
Ly_channel |
float |
2.0 |
Channel height |
>0 |
Grid
| Parameter |
Type |
Default Value |
Description / Notes |
Possible Values |
nx_global |
int |
N/A |
Total grid points in x |
>0 |
ny_global |
int |
N/A |
Total grid points in y |
>0 |
nz_global |
int |
N/A |
Total grid points in z |
>0 |
alpha_stretch |
float |
2.6 |
Stretching factor for grid |
≥1 |
grid_type |
int |
N/A |
Type of grid (uniform, stretched, etc.) |
0 (uniform), 1 (stretched grid wall to wall), 2 (stretched grid with uniform buffers on each end) |
min_buffer_width |
float |
0.0 |
Minimum buffer width for grid type 2 |
≥0 |
Solver Parameters
| Parameter |
Type |
Default Value |
Description / Notes |
Possible Values |
CFL |
float |
N/A |
If positive: CFL number for time-stepping. If negative: timestep size |
>0 (CFL number) or <0 (timestep size) |
nu |
float |
N/A |
Kinematic viscosity |
≥0 |
nsteps |
int |
N/A |
Total number of steps |
>0 |
Immersed boundary parameters
| Parameter |
Type |
Default Value |
Description / Notes |
Possible Values |
nxb |
int |
N/A |
Number of IB points in x |
≥0 |
nzb |
int |
N/A |
Number of IB points in z |
≥0 |
body_type |
string |
'none' |
Type of immersed body |
'none', 'center_wall', 'double_cylinders_z', 'standing_wave', traveling_wave_x', 'traveling_wave_z' |
body_param_1 |
float |
N/A |
Body-specific parameter 1 |
Depends on body type |
body_param_2 |
float |
N/A |
Body-specific parameter 2 |
Depends on body type |
body_param_3 |
float |
N/A |
Body-specific parameter 3 |
Depends on body type |
body_ramp_up_time |
float |
0 |
Ramp-up time for body motion (body-specific) |
≥0 |
cg_tol |
float |
1e-8 |
Tolerance for CG solver |
>0 |
cg_max_iter |
int |
50 |
Max iterations for CG solver |
>0 |
Initialization
| Parameter |
Type |
Default Value |
Description / Notes |
Possible Values |
nstep_init |
int |
N/A |
Initial time step |
≥0 |
t_init |
float |
0.0 |
Initial time |
≥0 |
init_type |
int |
N/A |
Type of initialization |
0 (initialize to the flow field from filein), 1 (zero initial conditions), 2 (random) |
perturb_scale |
float |
0.5 |
Scale of initial perturbations for random initialization |
≥0 |
filein |
string |
N/A |
Input file name for initialization |
Any valid file path |
Output / Monitoring
| Parameter |
Type |
Default Value |
Description / Notes |
Possible Values |
nsave |
int |
N/A |
Save interval (in timesteps) |
≥0 |
nstats |
int |
N/A |
Statistics interval (in timesteps) |
≥0 |
nmonitor |
int |
N/A |
Monitoring interval (in timesteps) |
≥0 |
fileout |
string |
N/A |
Output file name |
Any valid file path |
dPdx |
float |
0 |
Pressure gradient in x |
Any real number |
dPdz |
float |
0 |
Pressure gradient in z |
Any real number |
x_mass_cte |
int |
0 |
Switch for x-direction flow driving: 0 → constant pressure gradient, 1 → constant mass flow |
0 or 1 |
z_mass_cte |
int |
0 |
Switch for z-direction flow driving: 0 → constant pressure gradient, 1 → constant mass flow |
0 or 1 |