HYDE 10

Owing to a severe accident, explosions of Hydrogen are likely to occur inside the safety containment of a Nuclear Power Plant (TMI-2 and Chernobyl accidents). Therefore, it is important to have a mathematical model which, together with experimental tests, makes it possible to identify the explosion mechanism as well as to predict loads on the containment. On the basis of some hypotheses on the shape of the flame and on the thermofluiddynamic state of the mixture, the HYDE.10 code provides the pressure transient inside a closed vessel during the deflagration of a Hydrogen-Air-Steam mixture. Moreover, the code is able to define the flame shape, the burning velocity and the physical constants of the mixture. Finally, it defines the average values of the pressure and of the mean temperature for an abiabatic isochoric combustion as well as the flame temperature for an insenthalpic combustion. Despite the hypotheses, the analytical model has a wide range of applications and it is used to interpret the results of the experimental tests which are carried out at the Department of Nuclear and Mechanical Constructions of the University of Pisa