Consultation des notices

Some complex mechanical systems involve fractional or irrational differential operators. For instance, it is the case of the propagation in acoustic pipes with varying cross-sections including visco-thermal losses at the walls. A well-posed formalism, based on the so-called "diffusive representations" or "integral representations", is able to represent a class of such input-to-output systems: their transfer functions(/impulse responses) are bluit as parametrized continuous aggregations of transfer functions (/impulse reponses) of simple first order differential systems. Using this formalism, we propose finite dimensional approximations and an optimization methodthat yield low-cost and accurate time simulations.