.. _inputs_abl: Section: ABL ~~~~~~~~~~~~ This section is for setting atmospheric boundary layer parameters. .. input_param:: ABL.kappa **type:** Real, optional, default = 0.41 Wall model coefficient. .. input_param:: ABL.surface_roughness_z0 **type:** Real, optional, default = 0.1 Wall model surface roughness. .. input_param:: ABL.normal_direction **type:** Integer, optional, default = 2 Wall model normal direction. x-direction = 0, y-direction = 1, z-direction = 2. .. input_param:: ABL.log_law_height **type:** Real, optional Height to evaluate the log law for the wall model. Currently, if this parameter is not specified in the input file, the first half cell height is calculated and is used to set the log law height. Therefore the log law height depends on the domain size and number of elements in the normal direction. If this parameter is set to a number the log law is evaluated at a fixed height. Note: currently the fluctuating velocity terms in the shear stress model are only available at the first cell center above the wall. This limitation will be removed soon. .. input_param:: ABL.temperature_heights **type:** List of Reals, mandatory Height(s) in meters at which temperature values are prescribed. .. input_param:: ABL.temperature_values **type:** List of Reals (has to be same length as :input_param:`ABL.temperature_heights`), mandatory Temperature values in Kelvin at the corresponding :input_param:`ABL.temperature_heights`. The temperature below the first height is assumed to be constant and equal to the first temperature value. The temperature between values is initialized to have linear variation. The final temperature is constant above the last specified height. .. input_param:: ABL.perturb_velocity **type:** Boolean, optional, default = true If true this flag turns on perturbations to the freestream flow. .. input_param:: ABL.pertub_ref_height **type:** Real, optional, default = 50.0 Reference height for velocity perturbations, perturbations exist below this height and decay above this height. Only active when :input_param:`ABL.perturb_velocity` = true. .. input_param:: ABL.Uperiods **type:** Real, optional, default = 4.0 Number of sinusoidal waves in x-direction. Only active when :input_param:`ABL.perturb_velocity` = true. .. input_param:: ABL.Vperiods **type:** Real, optional, default = 4.0 Number of sinusoidal waves in y-direction. Only active when :input_param:`ABL.perturb_velocity` = true. .. input_param:: ABL.deltaU **type:** Real, optional, default = 1.0 Amplitude of fluctuations in x-direction. Only active when :input_param:`ABL.perturb_velocity` = true. .. input_param:: ABL.deltaV **type:** Real, optional, default = 1.0 Amplitude of fluctuations in y-direction. Only active when :input_param:`ABL.perturb_velocity` = true. .. input_param:: ABL.perturb_temperature **type:** Boolean, optional, default = false Perturb temperature field with random fluctuations. .. input_param:: ABL.theta_amplitude **type:** Real, optional, default = 0.8 K Amplitude of the temperature perturbations added to the initial field. Only active when :input_param:`ABL.perturb_temperature` is true. .. input_param:: ABL.cutoff_height **type:** Real, optional, default = domain height Height below which temperature perturbations are added .. input_param:: ABL.random_gauss_mean **type:** Real, optional, default = 0.0 Mean for the Gaussian random number generator .. input_param:: ABL.random_gauss_var **type:** Real, optional, default = 1.0 Variance for the Gaussian random number generator .. input_param:: ABL.bndry_file **type:** String, optional, default = "" NetCDF-4 file name for ABL inflow .. input_param:: ABL.bndry_io_mode **type:** Int, optional, default = -1 IO mode (0=output, 1=input) .. input_param:: ABL.bndry_planes **type:** String, optional, default = "" IO planes for ABL inflow .. input_param:: ABL.bndry_output_start_time **type:** Real, optional, default = 0.0 Time at which to start ABL inflow output .. input_param:: ABL.bndry_var_names **type:** String, optional, default = "" Variables for IO for ABL inflow .. input_param:: ABL.wall_shear_stress_type **type:** String, optional, default = "Moeng" Wall shear stress model: options include "constant", "local", "Schumann", and "Moeng" .. input_param:: ABL.bndry_output_format **type:** String, optional, default = "native" Output of boundary plane files. Valid values are ``netcdf`` and ``native``. .. input_param:: ABL.initial_condition_input_file **type:** String, optional, default= "" File that contains initial conditions for the velocity field in netcdf file format. This file is expected to have the same dimensions as the simulation. Values are passed directly from the file to the velocity field inside the code. Only spanwise velocity components are supported. .. input_param:: ABL.anelastic **type:** Boolean, optional, default= false Activate anelastic behavior. This adds `reference_density` and `reference_pressure` fields. .. input_param:: ABL.bottom_reference_pressure **type:** Real, optional, default = 1.01325e5 Reference pressure at the bottom of the domain. Used for anelastic ABL. .. input_param:: ABL.initial_wind_profile **type:** Boolean, optional, default= false Activates the reading of wind speed profile from a file. Recommended for RANS models and also for wind conditions input from climate model. .. input_param:: ABL.rans_1dprofile_file **type:** String, optional, default = "" This input is required when the ABL.initial_wind_profile is set to True. .. input_param:: ABL.meso_sponge_start **type:** Real, optional, default = 650 Approximate height of the planetary boundary layer height to enable the forcing in the free atmosphere. Recommended for use with RANS model and optionally to run LES with non canonical flow conditions. The method is enabled by default for turbulent kinetic energy. To enable this option for temperature and velocity, the following flags have to be added to the input file. `Temperature.source_terms = TemperatureFreeAtmosphereForcing` `ICNS.source_terms = VelocityFreeAtmosphereForcing`