Swing check valvecharacterization: 3D CFDvalidation of one dimensionalmodels used in RELAP5

Abstract: In a previous thesis work a swing check valve was studied with CFD analysisin order to nd correlations that could provide a good input for a onedimensionalmodel of the same. In this document, starting from the previousthesis results and using the model by Li and Liou as the reference work, a checkvalve is investigated and the hydraulic torque coecients identied. In this wayit becomes possible to analyze the behavior of the same valve with a 1D codecalled RELAP5.The rst part of the work was dedicated to understanding the dynamics lyingbehind the movement of swing check vale, and to the construction of a suitable3D CFD model being able to nd the required coecients. The results weresubsequently elaborated and implemented in the RELAP5 code, in order to runthe 1D simulations. In the second part of the job, several transient simulations ofdierent pipelines were conducted with the 1D model, monitoring in particularthe closure of the valve over time.In the end, the data obtained in RELAP5 were compared to those fromequivalent 3D CFD analysis and from an alternative 1D approach by Adamkowski.Although not completely matching, the results showed that the 1D model byLi and Liou has a good ability to accurately simulate the valve. Further workcould be surely done on particular topics in order to improve and tune thismodel, making it a consistent and cheaper alternative to 3D simulations, ableto accurately simulate a wide range of cases.