Aerospace Blockset | ![]() ![]() |
Library
Description
The Discrete Wind Gust Model block implements a wind gust of the standard "1-cosine" shape. This block implements the mathematical representation in the Military Specification MIL-F-8785C [1]. The gust is applied to each axis individually, or to all three axes at once. The user specifies the gust amplitude (the increase in wind speed generated by the gust), the gust length (length, in meters, over which the gust builds up) and the gust start time.
The Discrete Wind Gust Model block can represent the wind speed in units of feet per second, meters per second, or knots.
The following figure shows the shape of the gust with a start time of zero. The parameters that govern the gust shape are indicated on the diagram.
The discrete gust can be used singly or in multiples to assess airplane response to large wind disturbances.
The mathematical representation of the discrete gust is
where Vm is the gust amplitude, dm is the gust length, x is the distance traveled, and Vwind is the resultant wind velocity in the body axis frame.
Dialog Box
Wind |
Altitude |
|
Meters/second |
Meters/second |
Meters |
Feet/second |
Feet/second |
Feet |
Knots |
Knots |
Feet |
Inputs and Outputs
The input is altitude in units selected.
The output is wind speed in units selected.
Examples
See aeroblk_HL20.mdl
example included with the blockset.
References
Military Specification MIL-F-8785C, 5th November 1980.
See Also
Dryden Wind Turbulence Model
![]() | Direction Cosine Matrix to Quaternions | Dryden Wind Turbulence Model | ![]() |