Helically coiled tubes represent a valuable solution to improve the performance of nuclear reactor Steam Generators (SGs), as they are very attractive for Small-medium Modular Reactors (SMRs) of Generation III+, which require in particular compactness as all the primary system components are located inside the reactor vessel. In this paper, the two-phase flow of an air-water mixture in a helically coiled pipe is investigated with the Computational Fluid Dynamic (CFD) code ANSYS FLUENT. In particular, the two fluid Eulerian model implemented in the code is applied in the simulations. As the CFD simulation of two-phase flow is a very challenging subject, a preliminary validation is made by comparison with experimental measures of frictional pressure drop and void fraction available in literature. Particular attention is devoted to the settings and parameters that considerably affect the results of the simulations. The diameter of the dispersed phase, in particular, turns out to be a key parameter for the accuracy of the results. Despite some drawbacks, results are fairly accurate as time average values of the void fraction and the frictional pressure drop show satisfactory agreement with the experimental data. In addition, the code seems to catch the effect of the centrifugal force introduced by tube bending on the two-phase flow structure.
CFD Analysis of Air-Water Two-Phase Flow in a Helically Coiled Tube
COLOMBO, MARCO;CAMMI, ANTONIO;DE AMICIS, JACOPO;LORENZI, STEFANO;RICOTTI, MARCO ENRICO
2012-01-01
Abstract
Helically coiled tubes represent a valuable solution to improve the performance of nuclear reactor Steam Generators (SGs), as they are very attractive for Small-medium Modular Reactors (SMRs) of Generation III+, which require in particular compactness as all the primary system components are located inside the reactor vessel. In this paper, the two-phase flow of an air-water mixture in a helically coiled pipe is investigated with the Computational Fluid Dynamic (CFD) code ANSYS FLUENT. In particular, the two fluid Eulerian model implemented in the code is applied in the simulations. As the CFD simulation of two-phase flow is a very challenging subject, a preliminary validation is made by comparison with experimental measures of frictional pressure drop and void fraction available in literature. Particular attention is devoted to the settings and parameters that considerably affect the results of the simulations. The diameter of the dispersed phase, in particular, turns out to be a key parameter for the accuracy of the results. Despite some drawbacks, results are fairly accurate as time average values of the void fraction and the frictional pressure drop show satisfactory agreement with the experimental data. In addition, the code seems to catch the effect of the centrifugal force introduced by tube bending on the two-phase flow structure.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
