Hybrid Modelling with Second Order Fluid Stochastic Petri Nets

Stochastic Petri nets have been extended for the modelling of hybrid systems by adding uid places, that are lled and emptied continuously at random (normally distributed) rate. The ow rates as well as the discrete transition rates may depend on the content a uid place holds. The dynamics of the model are described by second order partial diierential equations, that can be solved by using an implicit Crank-Nicolson scheme. Reward measures such as the uid throughput can be computed from the continuous part of the solution. As an example we present a model of a chemical reactor.