Understanding Simulated Flight Dynamics

I get as much enjoyment from the engineering aspect of aviation as I get from flying. Here I will post info about current projects, experiments, ponderings and what-not.

My current research is focused on deciphering exactly how FS2002 and FS9 interpret the configuration data we give them. Once I know exactly how FS calculates everything I will be able to quickly generate the exact FDM I want, and create tools to be able to do "virtual wind-tunnel" testing much more quickly and acurately.

My email address appears at the bottom of each page on this site. If you are working on similar issues and would like to compare notes or split the workload, please contact me. The more people who can verify my findings the better.

Flight Simulator FDM Details for Sailplane Designers

A reference document of how FS handles flight-dynamics. Includes detailed analyses for both 2002 and fs9 of how to calculate forces and moments, etc. from the coefficients and derivatives. As the title implies, it is geared toward sailplane FDM designers although everything here applies equally to any fixed-wing aircraft. Engines are not analyzed at all, but some special topics of interest for sailplanes are discussed at length.

Download or view a work-in-progress snapshot here (available soon):

Tools

To read and write the ".air" file binary format I use AirUpdate by Jerry Beckwith, available from his excellent site, www.mudpond.us.

I've created an assortment of other tools which create or analyze configuration parameters. I plan to make these available here as they stablize and reach a suitable level of maturity.

Experiments and discussions

Negative flap travel: Why is it used and can we model it in FS?
Measuring glide polars: And general flight test methods
Airfoils in FS: Tailoring the lift slope curve to model a particular airfoil and wing geometry

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Copyright © 2004 Kris Feldmann