Aerodynamics for Aviator File Format (*.aero)

An aerodynamics file is an ASCII text file that is formatted for compatibility with STK and ends in a .aero extension. It defines a method used to compute lift, drag, angle of attack, sideslip and intermediate/derived values for an aircraft object using STK's Aviator capability.

Aero and prop files may be used in several different performance model representations with Aviator (standard aircraft, Advanced Fixed Wing, Missiles, and potential plugin representations) and it is important to understand that ultimate aircraft performance is not only a function of the underlying data, but also the code and algorithms that apply that data. An example of this involves computing the effect of thrust on lift. Each of the performance models make use of slightly different methods for performing that function based on the needs of the different representations. Some are more efficient but offer less accuracy, while others are more robust to highly nonlinear data. Each makes use of the data for its own purposes that may differ from the other representations. It is generally not possible to fly a complex high performance maneuver in one representation and achieve the exact same numbers for AOA or ThrustRequired or Ps as another representation. They should be very close, but because the different representations were established to meet specific requirements and apply to different use cases, they may differ slightly.

Keywords

An aerodynamics file contains some common elements called keywords, defined in the following table. Keywords and their associated values must precede the specification of the actual data points. Keywords used in aerodynamics files are not case-sensitive.

Keyword	Required	Description
Version: <major release number>.<minor release number>	No	The version of STK software for which the file is formatted. Files can be created in, and imported to, STK software versions either consistent with the file version stamp or a later version. Example: Version: 10.1 You can import a file created in and stamped with version 10.1 into STK software version 10.1 or later (version cannot be greater than the current STK version).
RefAreaM2:	No	The area of the lifting surface of the aircraft. If this keyword is omitted, you will be able to specify the parameter in the Aviator user interface.

Data column formats

Aerodynamics data is grouped into rows of four numerical values - coefficient of lift, airspeed (in Mach number), coefficient of drag, and angle of attack (in radians).

Data units in aerodynamics files are STK default units and cannot be changed. Each number is converted inside the application to the user-specified scenario units.

Sample .aero files

Click the links below to view sample .aero files:

Link	Description
Example 1	Altitude dependent, with detailed aero data. Includes a version string.
Example 2	Altitude dependent, without detailed aero data. Does not include a version string.
Example 3	Non-altitude dependent, with detailed aero data. Includes a version string.
Example 4	Non-altitude dependent, without detailed aero data. Includes a version string.
Example 5	Non-altitude dependent, with detailed aero data. Includes version string. For use with the Advanced Fixed Wing Tool.