NEW VERSION 28-Jan-2007, 1.2e. Physics redone and biomechanics handled better as described in accompanying paper in the links.
NEW VERSION 23-Aug-2005, 1.2d. Calibrated on two major championships and including biomechanical data.
This freely downloadable Windows software models the trajectory of a javelin. Its a self-installing executable so when you have downloaded it, just double-click on it and answer the questions, (which you can usually just default).
The Javelin Flight Analyser (JFA) is pretty sophisticated and solves a coupled non-linear set of ordinary differential equations including terms for drag, lift, rotation and allows for the difference between the centre of pressure where the aerodynamic forces act and the centre of mass. It has only been partially calibrated but already produces good results in a wide variety of environments. It also allows the user to specify the type of javelin, the wind direction and strength and various user parameters. It will shortly be able to search for the best combination given various wind combinations.
Version 1.2 has been upgraded from calibration information gained from publications in this area. They are referenced in the accompanying paper.
This is one of a series of projects I am undertaking to improve IT use in track and field, one of my significant interests. I hope you find it useful and will be pleased to receive any feedback.