Argonne researchers E. Merzari, H. Yuan, A. Kraus, A. Obabko, and P. Fischer and their colleagues at Lawrence Livermore National Laboratory and Texas A&M University have won a Best Paper Award at the 17th International Topical Meeting on Nuclear Reactor Thermal (NURETH-17), held in China in September 2017.
In their award-winning paper, titled “High-Fidelity Simulation of Flow Induced Vibrations in Helical Steam Generators for Small Modular Reactors,” the researchers describe the use of the computational fluid dynamics code Nek5000 coupled to the structural code Diablo to simulate the flow in helical coil heat exchangers and predict flow-induced vibrations. Such vibrations are of concern because they may cause tube failure, attrition against support structures, joint tightness faults, and fastener loosening. The research team initially simulated one-way coupling in the turbulent excitation regime and achieved results that agreed closely with the experimental values. For high flow conditions, where tighter coupling is needed, the researchers devised a full fluid-structure interaction solver. Numerous tests verified the accuracy of the solver, and results with benchmarks demonstrated that the new solver significantly reduces the number of iterations needed to achieve convergence within a time step.
“Flow-induced vibration can be crippling in steam generators: the units are expensive, and their replacement can involve long downtime. Moreover, the need for reliable steam generators has increased in recent years with the growing interest in small modular reactors,” said Elia Merzari, a principal nuclear engineer in Argonne’s Mathematics and Computer Science Division and Nuclear Engineering Division. “The advanced numerical simulation capability we have developed will help improve the analysis and evaluation of different design variants, complementing experimental tests and reducing their cost.”
The Nuclear Reactor Thermal Hydraulics (NURETH) series of conferences provides a forum for international experts and researchers in the field of nuclear reactor thermal hydraulics to share their research and discuss future developments. For information about NURETH-17 and the award, see the website.