pyatmos.utils package¶
pyatmos.utils.lookup module¶
Contains the following atmospheric functions:
- alt = get_alt_for_density(density, density_units=’slug/ft^3’, alt_units=’ft’,
- nmax=20, tol=5.)
- alt = get_alt_for_eas_with_constant_mach(equivalent_airspeed, mach,
- velocity_units=’ft/s’, alt_units=’ft’, nmax=20, tol=5.)
- alt = get_alt_for_q_with_constant_mach(q, mach, pressure_units=’psf’, alt_units=’ft’,
- nmax=20, tol=5.)
- alt = get_alt_for_pressure(pressure, pressure_units=’psf’, alt_units=’ft’,
- nmax=20, tol=5.)
All the default units are in English units because the source equations are in English units.
-
pyatmos.utils.lookup.get_alt_for_density(density, density_units='slug/ft^3', alt_units='ft', nmax=20, tol=5.0)[source]¶ Gets the altitude associated with a given air density.
Parameters: - density : float
the air density in slug/ft^3
- density_units : str; default=’slug/ft^3’
the density units; slug/ft^3, slinch/in^3, kg/m^3
- alt_units : str; default=’ft’
sets the units for the output altitude; ft, m, kft
- nmax : int; default=20
max number of iterations for convergence
- tol : float; default=5.
tolerance in alt_units
Returns: - alt : float
the altitude in feet
-
pyatmos.utils.lookup.get_alt_for_eas_with_constant_mach(equivalent_airspeed, mach, velocity_units='ft/s', alt_units='ft', nmax=20, tol=5.0)[source]¶ Gets the altitude associated with a equivalent airspeed.
Parameters: - equivalent_airspeed : float
the equivalent airspeed in velocity_units
- mach : float
the mach to hold constant
- alt_units : str; default=’ft’
the altitude units; ft, kft, m
- nmax : int; default=20
max number of iterations for convergence
- tol : float; default=5.
tolerance in alt_units
Returns: - alt : float
the altitude in alt units
-
pyatmos.utils.lookup.get_alt_for_pressure(pressure, pressure_units='psf', alt_units='ft', nmax=20, tol=5.0)[source]¶ Gets the altitude associated with a pressure.
Parameters: - pressure : float
the pressure lb/ft^2 (SI=Pa)
- pressure_units : str; default=’psf’
the pressure units; psf, psi, Pa, kPa, MPa
- alt_units : str; default=’ft’
the altitude units; ft, kft, m
- nmax : int; default=20
max number of iterations for convergence
- tol : float; default=5.
tolerance in alt_units
Returns: - alt : float
the altitude in alt_units
-
pyatmos.utils.lookup.get_alt_for_q_with_constant_mach(q, mach, pressure_units='psf', alt_units='ft', nmax=20, tol=5.0)[source]¶ Gets the altitude associated with a dynamic pressure.
Parameters: - q : float
the dynamic pressure lb/ft^2 (SI=Pa)
- mach : float
the mach to hold constant
- pressure_units : str; default=’psf’
the pressure units; psf, psi, Pa, kPa, MPa
- alt_units : str; default=’ft’
the altitude units; ft, kft, m
- nmax : int; default=20
max number of iterations for convergence
- tol : float; default=5.
tolerance in alt_units
Returns: - alt : float
the altitude in alt_units
pyatmos.utils.unitless module¶
Contains functions that have both consistent units and are vectorized:
- q = dynamic_pressure_p_mach(p, mach)
- q = dynamic_pressure_rho_vel(rho, vel)
- sos = speed_of_sound(T, R=1716., gamma=1.4)
-
pyatmos.utils.unitless.dynamic_pressure_p_mach(p, mach)[source]¶ Calculates dynamic pressure without options for units