QCD hydrodynamics for LHC and RHIC

The realistic and detailed description of an energetic heavy ion reaction requires a Multi Module Model, where the different stages of the reaction are each described with a suitable theoretical approach. One fluid dynamical models provide an adequate and accurate description of the middle stages of the reaction. In addition, fluid dynamical calculations require initial and freeze out conditions. In this work we concentrate on the modeling of the initial stages of the reaction, before the local thermal equilibrium is achieved, and on the freeze out process. We discuss the possibility of the fast simultaneous hadronization and chemical freeze out of supercooled QGP, as a possible solution of the HBT 'puzzle'.