Gerardo Toraldo

Title	Modeling and simulation of hydrodynamic conditions in a pasta extruder.
Abstract	In order to model any hydrodynamic operation, such as the shaping operation of pasta, it is necessary to build up a suitable mathematical model which allows one to relate the stress tensor to velocity profile and heat generation.. To do so one must write and solve an adequate set of differential equations which can be derived from the continuity principle and the momentum and heat conservation principles. Many computer programs, mainly developed to assist plant design in polymer technologies, exist on the market and can be used for this purpose. In our work we show how Polyflow, which is one of such computational tools can be tailored in an effective way to the specif ic problem of pasta extrusion. Many goals were intended to be achieved by performing the modelling step. In particular: a) analyse the fluxes of the system parameters; b) validate experimental results; c) verify the system response to die geometry modifications; d) validate some relationships between process results and process parameters for scaling up purpose. Extensive computational experiments show the effectiveness of our approach, both from the methodological and the experimental point of view, through several validations of the proposed model.
Authors	Silvana Cavella, Giannino Francesco, Paolo Masi, Gerardo Severino, Gerardo Toraldo
Institution	Dipartimento di Ingegneria Agraria e Agronomia del Territorio, Università degli Studi di Napoli Federico II