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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.

The function holds temperature and pressure values below the geopotential altitude of 0 km and above the geopotential altitude of the tropopause. The function calculates the density and speed of sound using a perfect gas relationship.

[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.

Input Arguments

height

Array of m-by-1 geopotential heights, in meters.

g

Scalar of acceleration due to gravity, in meters per second squared.

heatRatio

Scalar of specific heat ratio.

characteristicGasConstant

Scalar of characteristic gas constant, in joule per kilogram-kelvin.

lapseRate

Scalar of lapse rate, in kelvin per meter.

heightTroposphere

Scalar of height of troposphere, in meters.

heightTropopause

Scalar of height of tropopause, in meters.

density0

Scalar of air density at mean sea level, in kilograms per meter cubed.

pressure0

Scalar of static pressure at mean sea level, in pascal.

temperature0

Scalar of absolute temperature at mean sea level, in kelvin.

height0

Scalar of minimum sea level altitude, in meters.

Output Arguments

T

Array of m-by-1 temperatures, in kelvin.

a

Array of m-by-1 speeds of sound, in meters per second. The function calculates speed of sound using a perfect gas relationship.

P

Array of m-by-1 pressures, in pascal.

rho

Array of m-by-1 densities, in kilograms per meter cubed. The function calculates density using a perfect gas relationship.

Examples

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+004

rho =

    1.1116

References

U.S. Standard Atmosphere, 1976, U.S. Government Printing Office, Washington, D.C.

See Also

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