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COESA Atmosphere Model

Implement 1976 COESA lower atmosphere

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  • Aerospace Blockset / Environment / Atmosphere

  • COESA Atmosphere Model block

Description

TheCOESA Atmosphere Modelblock implements the mathematical representation of the 1976 Committee on Extension to the Standard Atmosphere (COESA) United States standard lower atmospheric values for absolute temperature, pressure, density, and speed of sound for the input geopotential altitude.

TheCOESA Atmosphere Model,Non-Standard Day 210C, andNon-Standard Day 310blocks are identical blocks. When configured forCOESA Atmosphere Model, the block implements the COESA mathematical representation. When configured forNon-Standard Day 210C, the block implements MIL-STD-210C climatic data. When configured forNon-Standard Day 310, the block implements MIL-HDBK-310 climatic data.

Below 32,000 meters (approximately 104,987 feet), the U.S. Standard Atmosphere is identical with the Standard Atmosphere of the International Civil Aviation Organization (ICAO).

TheCOESA Atmosphere Modelblock port labels change based on the input and output units selected from theUnitslist.

Limitations

Below the geopotential altitude of 0 m (0 feet) and above the geopotential altitude of 84,852 m (approximately 278,386 feet), temperature values are extrapolated linearly and pressure values are extrapolated logarithmically. Density and speed of sound are calculated using a perfect gas relationship.

Ports

Input

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Geopotential height, specified as a scalar or array, in specified units.

Data Types:double

Output

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Temperature, specified as a scalar or array, in specified units.

Data Types:double

Speed of sound, specified as a scalar or array, in specified units.

Data Types:double

Air pressure, specified as a scalar or array, in specified units.

Data Types:double

Air density, specified as a scalar or array, in specified units.

Data Types:double

Parameters

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Input and output units, specified as:

Units

Height

Temperature

Speed of Sound

Air Pressure

Air Density

Metric (MKS)

Meters

Kelvin

Meters per second

Pascal

Kilograms per cubic meter

English (Velocity in ft/s)

Feet

Degrees Rankine

Feet per second

Pound-force per square inch

Slug per cubic foot

English (Velocity in kts)

Feet

Degrees Rankine

Knots

Pound-force per square inch

Slug per cubic foot

Programmatic Use

Block Parameter:units
Type: character vector
Values:'Metric (MKS)'|'English (Velocity in ft/s)'|'English (Velocity in kts)'
Default:'Metric (MKS)'

Atmosphere model type, specified as1976 COESA-extended U.S. Standard Atmosphere,MIL-HDBK-310, orMIL-STD-210C. For theMIL-HDBK-310andMIL-STD-210Coptions:

MIL-HDBK-310

This selection is linked to theNon-Standard Day 310block. See the block reference for more information. SelectingMIL-HDBK-310enables the parametersAtmospheric model type,Extreme parameter,Frequency of occurrence, andAltitude of extreme value.

MIL-STD-210C

This selection is linked to theNon-Standard Day 210Cblock. See the block reference for more information. SelectingMIL-HDBK-310enables the parametersAtmospheric model type,Extreme parameter,Frequency of occurrence, andAltitude of extreme value.

Dependencies

SelectingMIL-HDBK-310orMIL-STD-210Cenables these parameters:

  • Atmospheric model type

  • Extreme parameter

  • Frequency of occurrence

  • Altitude of extreme value

Programmatic Use

Block Parameter:spec
Type: character vector
Values:'1976 COESA-extended U.S. Standard Atmosphere'|'MIL-HDBK-310'|'MIL-STD-210C'
Default:'1976 COESA-extended U.S. Standard Atmosphere'

Representation of atmospheric model type, specified as:

Profile Realistic atmospheric profiles associated with extremes at specified altitudes. Recommended for simulation of vehicles vertically traversing the atmosphere or when the total influence of the atmosphere is needed.
Envelope Uses extreme atmospheric values at each altitude. Recommended for vehicles only horizontally traversing the atmosphere without much change in altitude.

Dependencies

  • SelectingMIL-HDBK-310orMIL-STD-210Cfor theSpecificationparameter enables this parameter.

  • SelectingProfileenables theAttitude of extreme valueparameter.

Programmatic Use

Block Parameter:model
Type: character vector
Values:'Profile'|'Envelope'
Default:'Profile'

Atmospheric parameter that is the extreme value.

Dependencies

  • SelectingMIL-HDBK-310orMIL-STD-210Cfor theSpecificationparameter enables this parameter.

  • TheHigh pressureandLow pressureoptions appear only whenAtmospheric model typeis set toEnvelope.

Programmatic Use

Block Parameter:profile_var
Type: character vector
Values:'High temperature'|'Low temperature'|'High density'|'Low density'|'High pressure'|'Low pressure'
Default:'High temperature'

Percent of time the values would occur.

Dependencies

  • SelectingMIL-HDBK-310orMIL-STD-210Cfor theSpecificationparameter enables this parameter.

  • Extreme values,5%, and20%are available only whenEnvelopeis selected forAtmospheric model type.

  • 1%and10%are always available.

Programmatic Use

Block Parameter:profile_percent
Type: character vector
Values:'Extreme values'|'1%'|“5%”|'10%'|'20%'
Default:'1%'

几何海拔的极端values occur, specified as5 km (16404 ft),10 km (32808 ft),20千米(65617英尺),30 km (98425 ft), or40 km (131234 ft).

Dependencies

This parameter appears if theAtmospheric model typeis set toProfile.

Programmatic Use

Block Parameter:profile_alt
Type: character vector
Values:5 km (16404 ft)|10 km (32808 ft)|20千米(65617英尺)|30 km (98425 ft)|40 km (131234 ft)
Default:40 km (131234 ft)

Out-of-range block behavior, specified as follows.

Action Description

None

No action.

Warning

Warning in the Diagnostic Viewer, model simulation continues.

Error(default)

MATLAB®returns an exception, model simulation stops.

Programmatic Use

Block Parameter:action
Type: character vector
Values:'None'|'Warning'|'Error'
Default:'Warning'

Model Examples

True Airspeed from Indicated Airspeed Calculation

True Airspeed from Indicated Airspeed Calculation

How to compute true airspeed from indicated airspeed using the Ideal Airspeed Correction block. The Aerospace Blockset™ blocks are indicated in red.
Open Model
Indicated Airspeed from True Airspeed Calculation

Indicated Airspeed from True Airspeed Calculation

How to compute the indicated airspeed from true airspeed using the Ideal Airspeed Correction block. The Aerospace Blockset™ blocks are indicated in red.
Open Model

References

[1]U.S. Standard Atmosphere., Washington, D.C.: U.S. Government Printing Office, 1976.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

版本;n History

Introduced before R2006a

See Also

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