As a skydiver adds more gear such as front packs and items strapped to legs or arms, the jumper’s basic stability in free-fall is reduced. It becomes easier to tumble out of control and there is less margin for error. Similarly, the aerodynamic wake of the jumper may interfere with pilot chute opening (known as “hesitation”). Investigating different gear configurations generally involves vertical wind tunnel testing, or actual tests with jumpers. To avoid some of the cost, and mitigating safety concerns, a tool to computationally analyze these jumpers and their gear is highly desired. Creare, Inc., an R+D research firm in Hanover, NH, under funding from the US Army, developed a Computation Fluid Dynamics toolkit for analyzing jumpers and their equipment, and model the resulting configurations in FlightGear.
Note: a flyable parachutist model is available to download and test at the end of this article.
Where is the Parachute?
This exercise is setup as a free-fall simulation, not a parachute simulation so there is no chute modeled. Instead the simulation is mercifully paused when the altitude reaches 100′ above the surface.
Download and Fly
Follow these instructions to download, install, and fly the Creare Parachutist model:
- Note: the parachutist model is not compatible with FlightGear v2.4, you must fly this model with one of the v2.6 release candidates, or the official v2.6 release scheduled for February 17.
- Download the Creare_Parachutist-v1.0.zip file.
- Unzip it into your FlightGear “Aircraft” folder.
- Start FlightGear and select either –aircraft=Parachutist-Scenario1 or –aircraft=Parachutist-Scenario2
- Make sure you specify an initial altitude (such as –altitude=10000), otherwise you will just be sitting at the end of the runway working on your tan.
- Press F1 and F2 to toggle the two available dialog boxes on/off.
- You can manipulate the joint poses individually or select from a set of pre-defined poses, or select “Joystick” control and fly with a joystick (or keyboard or mouse) similar to flying a helicopter or airplane.
That's awesome and you know it!
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