DESIGN OF A TWO-PHASE FLOW FORCED CONVECTION LOOP FOR TWO-PHASE INSTABILITY ANALYSIS

Two phase flow instabilities and thermal-hydraulic oscillations are unwanted effects which can result in mechanical vibrations and system control problems, affecting normal operation, restricting operating parameters and influencing system safety. This instabilities can be found in several industrial systems such as heat exchangers, thermal-siphons, re-boilers, nuclear reactor, etc, and restrict the design and operation of industrial systems. Accurate simulations on these kind of systems represent a very challenge topic both theoretically, to understand the internal dynamics involved, and numerically, to developed tools able to solve this complex system. In this work, the modeling of two-phase instabilities in a heated pipe is presented as a supporting tool for the design of an experimental facility. A full criteria of similitude using non-dimensional numbers is described. The occurrence of both Ledinegg instability phenomena and density waves oscillations are studied through numerical simulations. Finally a full description of the criteria used in the design of this two-phase flow loop is presented.