The configuration file
The .conf file contains different options which specify the problem that APM will solve. The contents of an example .conf file are shown below:
c_ref = 1
b_ref = 1
S_ref = 1
x_cg = 0
y_cg = 0
z_cg = 0
trailing_edge_angle = 150
p_ref = 101325
rho_ref = 1.225
mu_ref = 1.789e-5
norm_V_ref = 1
M_ref = 0
alpha = 0
beta = 0
p = 0
q = 0
r = 0
dt = 1
N_timesteps = 1
restart_from_checkpoint = 0
wake_alignment = 0
wake_angle = 0
wake_rollup = 1
output_frequency = 1
paraview_output = 1
tecplot_output = 0
json_output = 0
doublet_gradient_scheme = 0
neighbour_tolerance = 1e-6
trefftz_plane_analysis = 0
tip_panels =
symmetry = 0
The values in the above .conf file are in SI units - m, kg, s. You can use different units as long as they are consistent across the .conf file.
Refer to the table below for a detailed description of each option.
Option | Dimension | Description | Default value |
c_ref | | Reference chord, used for non-dimensionalisation of the aerodynamic coefficients | 1 |
b_ref | | Reference span, used for non-dimensionalisation of the aerodynamic coefficients | 1 |
S_ref | | Reference area, used for non-dimensionalisation of the aerodynamic coefficients | 1 |
x_cg, y_cg, z_cg | | Location of the centre of gravity | 0 |
trailing_edge_angle | - | Edges sharper than the trailing edge angle in degrees are identified as trailing edges | 150 |
p_ref | | Reference pressure | 101325 |
rho_ref | | Reference density | 1.225 |
mu_ref | | Reference dynamic viscosity | 1.789e-5 |
norm_V_ref | | Reference freestream speed | 1 |
M_ref | - | Reference Mach number (used for compressibility corrections) | 0 |
alpha, beta | - | Angle of attack and angle of sideslip with respect to the freestream in degrees | 0 |
p, q, r | | Roll, pitch, and yaw rates in degrees/sec | 0 |
dt | | Time step | 1 |
N_timesteps | - | Number of timesteps | 1 |
restart_from_checkpoint | - | Instructs the solver to restart the solution from a checkpoint | 0 |
wake_alignment, wake_angle | - | Specifies how the wake aligns with respect to the trailing edges | 0 |
wake_rollup | - | If disabled the induced velocities from the body on the wake and on the wake iteslf wont be calculated. The wake will be translated with the reference freestream speed. | 1 |
json_output,
paraview_output, tecplot_output | - | Enables or disables JSON, ParaView, and Tecplot output | 0 |
doublet_gradient_scheme | - | 0 | |
neighbour_tolerance | - | Specifies the neighbour tolerance criteria | 1e-6 |
tip_panels | - | Instructs the solver to label specific panels as type 6 | Empty |
symmetry | - | Enables symmetry across the x-y plane. The solutions 2x faster and the memory requirements are 2x lower. | 0 |
Last modified 7mo ago