atmoslapse

Use Lapse Rate Atmosphere model

Syntax

[T,a,P,rho] = atmoslapse(height,g,heatRatio,characteristicGasConstant,lapseRate,heightTroposphere,heightTropopause,density0,pressure0,temperature0)

[T,a,P,rho] = atmoslapse(height,g,heatRatio,characteristicGasConstant,lapseRate,heightTroposphere,heightTropopause,density0,pressure0,temperature0,height0)

Description

[T,a,P,rho] = atmoslapse(height,g,heatRatio,characteristicGasConstant,lapseRate,heightTroposphere,heightTropopause,density0,pressure0,temperature0) implements the mathematical representation of the lapse rate atmospheric equations for ambient temperature, pressure, density, and speed of sound for the input geopotential altitude. To customize this atmospheric model, specify the atmospheric properties in the function input.

[T,a,P,rho] = atmoslapse(height,g,heatRatio,characteristicGasConstant,lapseRate,heightTroposphere,heightTropopause,density0,pressure0,temperature0,height0) indicates that the values for ambient temperature, pressure, density, and speed of sound are for below mean sea level geopotential altitudes.

The function holds temperature and pressure values below the geopotential altitude of height0 and above the geopotential altitude of the tropopause. The function calculates the density and speed of sound using a perfect gas relationship.

Examples

Calculate Lapse Rate Atmosphere Using International Standard Atmosphere

Calculate the atmosphere at 1000 m with the International Standard Atmosphere input values.

[T,a,P,rho] = atmoslapse(1000,9.80665,1.4,287.0531,0.0065, ...
    11000,20000,1.225,101325,288.15)

T =

  281.6500

a =
  336.4341

P =
   8.9875e+04

rho =
    1.1116

Input Arguments

height — Geopotential heights

m-by-n array

Geopotential heights, specified as an m-by-n array in meters.

Data Types: double

g — Acceleration

scalar

Acceleration due to gravity, specified as a scalar in meters per second squared.

Data Types: double

heatRatio — Heat ratio

scalar

Heat ratio, specified as a scalar.

Data Types: double

characteristicGasConstant — Characteristic gas constant

scalar

Characteristic gas constant, specified as a scalar in joules per kilogram-kelvin.

Data Types: double

lapseRate — Lapse rate

scalar

Lapse rate, specified as a scalar in kelvin per meter.

Data Types: double

heightTroposphere — Height of troposphere

scalar

Height of troposphere, specified as a scalar in meters.

Data Types: double

heightTropopause — Height of tropopause

scalar

Height of tropopause, specified as a scalar in meters.

Data Types: double

density0 — Density at mean sea level

scalar

Density at mean sea level (MSL), specified as a scalar in kilograms per meter cubed.

Data Types: double

pressure0 — Static pressure

scalar

Static pressure at MSL, specified as a scalar in pascal.

Data Types: double

temperature0 — Absolute temperature

scalar

Absolute temperature at MSL, specified as a scalar in kelvin.

Data Types: double

height0 — Minimum sea level altitude

0 (default) | scalar

Minimum sea level altitude, specified as a scalar in meters.

Data Types: double

Output Arguments

T — Temperatures

m-by-1 array

Temperatures, returned as an m-by-1 array in kelvin.

a — Speeds of sound

m-by-1 array

Speeds of sound, returned as an m-by-1 array in meters per second squared. The function calculates speed of sound using a perfect gas relationship.

P — Pressures

m-by-1 array

Pressures, returned as an m-by-1 array in pascal.

rho — densities

m-by-1 array

Densities, specified as an m-by-1 array kilograms per meter cubed. The function calculates density using a perfect gas relationship.

References

[1] U.S. Standard Atmosphere. Washington, DC: US Government Printing Office, 1976.

Version History

Introduced in R2006b