Section: Momentum Sources

ICNS.source_terms

type: String(s), optional

Activates source terms for the incompressible Navier-Stokes momentum equations. These strings can be entered in any order with a space between each. Please consult AMR-Wind developer documentation for a comprehensive list of all momentum source terms available. Note that the following input arguments specific to each source term will only be active if the corresponding source term (the root name) is listed in ICNS.source_terms.

BoussinesqBuoyancy.reference_temperature

type: Real, mandatory

Reference temperature \(\theta_\mathrm{ref}\) in Kelvin. Values of the temperature field that are less than or greater than this value will cause a buoyancy force in the direction of the gravity vector.

BoussinesqBuoyancy.thermal_expansion_coeff

type: Real, optional, default \(\beta = 1 / \theta_\mathrm{ref}\)

Thermal expansion coefficient, if not specified this value is set to the inverse of the BoussinesqBuoyancy.reference_temperature value.

CoriolisForcing.latitude

type: Real, mandatory

Latitude in degrees where the Coriolis forcing is computed. Positive values indicate northern hemisphere.

CoriolisForcing.rotational_time_period

type: Real, optional, default = 86400.0

Rotational time period of a day in seconds.

CoriolisForcing.east_vector

type: List of 3 reals, optional, default = 1.0 0.0 0.0

East vector that gives the orientation of the grid w.r.t. to planetary coordinate system. This vector is automatically normalized within amr-wind.

CoriolisForcing.north_vector

type: List of 3 reals, optional, default = 0.0 1.0 0.0

North vector that gives the orientation of the grid w.r.t. to planetary coordinate system. This vector is automatically normalized within amr-wind.

GeostrophicForcing.geostrophic_wind

type: List of 3 reals, optional

The user has to choose between GeostrophicForcing and ABLForcing. CoriolisForcing input must be present when using GeostrophicForcing. These checks are not enforced for now.

GeostrophicForcing.geostrophic_wind_timetable

type: String, optional

Input file name for table that lists time in seconds, wind speed in meters per second, and horizontal wind direction in degrees of the Geostrophic forcing velocity. Each line in the file should be a sequence of three floats specifying the inputs in that order (e.g., 0.0 8.0 -5.0). If this argument is present, the GeostrophicForcing.geostrophic_wind will be ignored. Note that the code expects there to be a single-line header at the beginning of the geostrophic wind timetable file; if no header exists, the first line of data will be ignored.

ABLForcing.abl_forcing_height

type: Real, mandatory

Height in meters at which the flow is forced to maintain the freestream inflow velocities specified through incflo.velocity.

ABLForcing.velocity_timetable

type: String, optional

Input file name for table that lists time in seconds, wind speed in meters per second, and horizontal wind direction in degrees of the ABL forcing velocity. Each line in the file should be a sequence of three floats specifying the inputs in that order (e.g., 0.0 8.0 -5.0). If this argument is present, the incflo.velocity argument will be ignored. Note that the code expects there to be a single-line header at the beginning of the velocity timetable file; if no header exists, the first line of data will be ignored.

ABLForcing.forcing_timetable_output_file

type: String, optional

Output file name for writing the ABL forcing vector to a text file over the course of a simulation. This output is primarily intended for replicating the ABL forcing from a precursor simulation in a subsequent inflow-outflow simulation by providing an input file for Body Forcing. The output file will contain the time and three vector components of the force.

ABLForcing.forcing_timetable_frequency

type: Int, optional

The interval of timesteps for writing to the forcing timetable output file. The default is 1, i.e., writing every step, which is also the default of the boundary plane output feature.

ABLForcing.forcing_timetable_start_time

type: Real, optional

The start time for writing to the forcing timetable output file. The default is 0.

BodyForce.type

type: String, optional

The type of body force being used. The default is uniform_constant, which applies a single constant force vector over the entire domain. Other available types are height_varying, oscillatory, and uniform_constant.

BodyForce.magnitude

type: List of 3 reals, conditionally mandatory

The force vector to be applied as a body force. This argument is mandatory for uniform_constant (default) and oscillatory body force types.

BodyForce.angular_frequency

type: Real, conditionally mandatory

The angular frequency to be used for applying sinusoidal time variation to the body force. This argument is mandatory for the oscillatory body force type and is only active for the oscillatory type.

BodyForce.bodyforce_file

type: String, conditionally mandatory

The text file for specifying the body force vector as a function of height. This text file must contain heights (z coordinate values), force components in x, and force components in y. This argument is mandatory for the height_varying body force type and is only active for the height_varying type.

BodyForce.uniform_timetable_file

type: String, conditionally mandatory

The text file for specifying the body force vector as a function of time. This text file must contain times, force components in x, force components in y, and force components in z. This argument is mandatory for the uniform_timetable body force type and is only active for the uniform_timetable type. Note that the code expects there to be a single-line header at the beginning of the uniform timetable file; if no header exists, the first line of data will be ignored.