Horizontal Wind Model

Transform horizontal wind into body-axes coordinates

• Library:

• Aerospace Blockset / Environment / Wind

• 

Description

The Horizontal Wind Model block computes the wind velocity in body-axes coordinates.

The wind is specified by wind speed and wind direction in Earth axes. The speed and direction can be constant or variable over time. The direction of the wind is in degrees clockwise from the direction of the Earth x-axis (north). The wind direction is defined as the direction from which the wind is coming. Using the direction cosine matrix (DCM), the wind velocities are transformed into body-axes coordinates.

Ports

Input

DCM — Direction cosine matrix

3-by-3 matrix

Direction cosine matrix, specified as a 3-by-3 matrix representing the flat Earth coordinates to body-fixed axis coordinates.

Data Types: double

Vwind — Wind speed

1-by-3 vector

Wind speed, specified as a 1-by-3 vector, in selected units.

Dependencies

To enable this parameter, set Wind speed source to External.

Data Types: double

θwind — Wind direction

scalar

Wind direction, specified as a scalar, in degrees. The direction of the wind is in degrees clockwise from the direction of the Earth x-axis (north). The wind direction is defined as the direction from which the wind is coming.

Dependencies

To enable this parameter, set Wind direction source to External.

Data Types: double

Output

Vwind — Wind velocity

3-by-3 matrix

Wind velocity, returned as a three-element signal in the same body coordinate reference as the DCM input, in specified units.

Data Types: double

Parameters

Units — Input and output units

Metric (MKS) (default) | English (Velocity in ft/s) | English (Velocity in kts)

Input and output units, specified as:

Units	Wind Speed	Wind Velocity
Metric (MKS)	Meters per second	Meters per second
English (Velocity in ft/s)	Feet per second	Feet per second
English (Velocity in kts)	Knots	Knots

Programmatic Use

Block Parameter: units

Type: character vector

Values: 'Metric (MKS)' | 'English (Velocity in kts)' | 'English (Velocity in ft/s)'

Default: 'Metric (MKS)'

Wind speed source — Wind speed source

Internal (default) | External

Wind speed source, specified as:

External	Variable wind speed input to block
Internal	Constant wind speed specified in mask

Dependencies

• Setting this parameter to Internal enables Wind speed at altitude.

• Setting this parameter to External enables the V_wind input port.

Programmatic Use

Block Parameter: Vw_source

Type: character vector

Values: 'Internal' | 'External'

Default: 'Internal'

Wind speed at altitude (m/s) — Wind speed

15 (default) | scalar

Constant wind speed, specified as a double scalar, in specified units.

Dependencies

To enable this parameter, set Wind speed source to Internal.

Programmatic Use

Block Parameter: Vwind

Type: character vector

Values: scalar

Default: '15'

Wind direction source — Wind direction source

Internal (default) | External

Wind direction source, specified as:

External	Variable wind direction input to block
Internal	Constant wind direction specified in mask

Dependencies

• Setting this parameter to Internal enables Wind direction at altitude (degrees clockwise from north).

• Setting this parameter to External enables the θ_wind input port.

Programmatic Use

Block Parameter: W_source

Type: character vector

Values: 'Internal' | 'External'

Default: 'Internal'

Wind direction at altitude (degrees clockwise from north) — Wind direction

0 (default)

Constant wind direction, specified as a scalar, in degrees clockwise from the direction of the Earth x-axis (north). The wind direction is the direction from which the wind is coming.

Dependencies

To enable this parameter, set Wind direction source to Internal.

Programmatic Use

Block Parameter: Wdeg

Type: character vector

Values: scalar

Default: '0'

Extended Capabilities

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

Version History

Introduced before R2006a