Source code for RCAIDE.Library.Attributes.Atmospheres.Earth.Constant_Temperature
# RCAIDE/Library/Attributes/Atmospheres/Earth/Constant_Temperature.py
#
#
# Created: Mar 2024, M. Clarke
# ----------------------------------------------------------------------------------------------------------------------
# Imports
# ----------------------------------------------------------------------------------------------------------------------
from RCAIDE.Framework.Core import Data , Units
from RCAIDE.Library.Attributes.Gases import Air
from RCAIDE.Library.Attributes.Atmospheres import Atmosphere
from RCAIDE.Library.Attributes.Planets import Earth
import numpy as np
# ----------------------------------------------------------------------------------------------------------------------
# Constant_Temperature Class
# ----------------------------------------------------------------------------------------------------------------------
[docs]
class Constant_Temperature(Atmosphere):
"""
Modified US Standard Atmosphere 1976 model with constant temperature profile.
This class implements a simplified atmospheric model where temperature remains constant
across all altitudes while maintaining US Standard 1976 pressure and density variations.
Attributes
----------
fluid_properties : Air
Air properties object containing gas characteristics
planet : Earth
Earth properties object containing planetary parameters
breaks : Data
Container for atmospheric property breakpoints
- altitude : array
Geopotential altitude points in meters
- temperature : array
Temperature values at break points (constant 301.15 K)
- pressure : array
Pressure values at break points in Pascal
- density : array
Density values at break points in kg/m³
Notes
-----
This model is useful for simplified analyses where temperature variations
with altitude are not critical, while still maintaining realistic pressure
and density gradients.
**Major Assumptions**
* Temperature remains constant at 301.15 K across all altitudes
* Pressure and density variations follow US Standard 1976 model
* Valid from -2 km to 84.852 km geopotential altitude
References
----------
[1] NOAA, NASA, USAF, U.S. Standard Atmosphere, 1976 (1976). Retrieved December 30, 2024, from https://www.ngdc.noaa.gov/stp/space-weather/online-publications/miscellaneous/us-standard-atmosphere-1976/us-standard-atmosphere_st76-1562_noaa.pdf.
See Also
--------
RCAIDE.Library.Attributes.Atmospheres.Earth.US_Standard_1976 : Full US Standard Atmosphere implementation
"""
def __defaults__(self):
"""This sets the default values at breaks in the atmosphere.
Assumptions:
Constant temperature
Source:
U.S. Standard Atmosphere (1976 version)
Inputs:
None
Outputs:
None
Properties Used:
None
"""
self.fluid_properties = Air()
self.planet = Earth()
self.breaks = Data()
self.breaks.altitude = np.array( [-2.00 , 0.00, 11.00, 20.00, 32.00, 47.00, 51.00, 71.00, 84.852]) * Units.km # m, geopotential altitude
self.breaks.temperature = np.array( [301.15 , 301.15, 301.15, 301.15, 301.15, 301.15, 301.15, 301.15, 301.15]) # K
self.breaks.pressure = np.array( [127774.0 , 101325.0, 22632.1, 5474.89, 868.019, 110.906, 66.9389, 3.95642, 0.3734]) # Pa
self.breaks.density = np.array( [1.545586 , 1.2256523,.273764, .0662256, 0.0105000 , 1.3415E-03, 8.0971E-04, 4.78579E-05, 4.51674E-06]) #kg/m^3
pass
