Z203 from System Zoo 1 p88-90

A PID control loop for a simple linear system

A simple piston with rod length l and crank radius r.

Adapted from an ithink model by Jim Rogers. See http://en.wikipedia.org/wiki/Harmonic_oscillator 

An steel cylinder oscillates inside a glass tube and over confined air within a glass bottle. As consecuence one observes an oscilation of the inside presure and the inner energy (temperature).

This shows the motion of a damped harmonic oscillator, described in terms of the undamped natural frequency, and a frequency gamma that reflects the degree of damping, parameterized as a damping ratio gamma/natural frequency. An accurate solution requires a small time step and RK4 as the integration algorithm.

D'après l'article Wikipedia

Z207 from Hartmut Bossel System Zoo 1 p103-107

After running the default settings Bossel describes A=0.2, B=0.2, Initial Values X=0 Y=2 and Z=0 and varying C=2,3,4,5 shows period doubling and transition to chaotic behavior

NOT YET FUNCTIONAL

This is a simple energy balance model of radiation through the atmosphere. It's a simple single layer model.

The underlying differential equation for this very minimal model is a non-dimensional version of the equation for an RC circuit, with charge measured in units of C*emf, and time measured in units of RC.

Fall with weight force, air friction force (e.g. an air balloon) and buoyancy force of the balloon in air

This shows the motion of a driven damped harmonic oscillator, described in terms of the undamped natural frequency, and a frequency gamma that reflects the degree of damping, parameterized as a damping ratio gamma/natural frequency.