JSBSim

JSBSim is an open source Flight Dynamics Model (FDM) software library that models the flight dynamics of an aerospace vehicle. The library has been incorporated into the flight simulation packages FlightGear and OpenEaagles. It can also be called from a small standalone program to create a batch simulation tool. JSBSim has been in development and use since 1996, and has been built on all of the most popular platforms in use today including those running Linux, Macintosh, and Microsoft Windows operating systems. JSBSim is written in C++ and uses XML configuration files.

• JSBSim is also used by OpenEaagles
• JSBSim Commander is a software program for developing FDM for aircraft with JSBSim.

Overview

JSBSim provides several different physics models which work together to calculate the overall vehicle dynamics.

• Mass Balance
• Ground Reactions
• Propulsion
• Aerodynamics
• Buoyant forces
• External forces
• Atmosphere
• Gravity

Aeromatic

See Aeromatic Readme for the main article about this subject.

Aeromatic can be used to create aircraft configuration files for use with the JSBSim Flight Dynamics Model. The configuration file format produced using this utility is version 2.0, and is incompatable with older formats because of an extensive overhaul of JSBSim's XML code that occured in December of 2004. Aeromatic is a online web tool, written in PHP, not a standalone program.

You will need at least three files for a complete configuration, an aircraft file containing information on the aircraft's mass properties, propulsion, flight control, aerodynamic properties, etc., an engine file describing the engine(s), and a thruster file. Thrusters can be rotors, propellers, nozzles or direct. All turbine engines use the default "direct" thruster. Piston, electric and turboprops need rotors or propellers. Rockets need nozzles. Aeromatic will generate plausible configuration files for your aircraft using some simplifying assumptions. Note that Aeromatic allows only one type of engine to be defined per aircraft. If you want to mix engine types you'll have to make the necessary changes by hand.

Be careful when tweaking the resulting configuration file, because it's easy to make changes that will result in an unflyable FDM. Common errors are: moving things around so they are not left/right symmetrical, and moving the CG too far away from the AeroRP.

Related content

• JSBSim Aerodynamics notes
• JSBSim GroundReactions
• JSBSim Engine configuration
• JSBSim Thruster configuration

External links

• JSBSim web site
• JSBSim Reference Manual (in-work, PDF)
• JSBSim Commander (beta)
• Aeromatic
• DATCOM+