Comparison of experimental and simulation results on interior subchannels of a 61-pin wire-wrapped hexagonal fuel bundle

Goth, Nolan; Jones, P.; Nguyen, Diep Thi Ngoc; Vaghetto, Rodolfo; Hassan, Yassin A.; Obabko, Aleksandr; Merzari, Elia; Fischer, Paul

doi:10.1016/j.nucengdes.2018.08.002

Cited by 29 publications

(9 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…4 shows the contour plot of the time-averaged axial velocity component v, for the considered values of Reynolds numbers. A lowspeed region appears at the downstream side of the wire, which is also found in Goth et al (2018). This low-speed region is more spread-out at the lower Reynolds numbers and it becomes narrower as the Reynolds increases.…”

Section: Time-averaged Velocity Fieldssupporting

confidence: 58%

“…Sato et al (2009) focused on the flow field inside the gap of a 7rods, wire-wrapped hexagonal bundle, observing a lateral flow following the wrapping direction of the wire. Recently, the university of Texas performed a number of experiments in a 61-rods test section for code validation, as reported in Goth et al (2018), and for studying vortical structures that may occur in the flow, as described in and in . Computational Fluid Dynamics (CFD) studies have focused on modelling the flow around a single wrapped-wire pin (Shams et al, 2018;Fischer et al, 2007), and on simulating the entire bundle for validation purposes (Pointer et al, 2008;Merzari et al, 2016;Obabko et al, 2016;Brockmeyer et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Understanding migratory flow caused by helicoid wire spacers in rod bundles: An experimental and theoretical study

Bertocchi

Rohde

Kloosterman

2019

International Journal of Heat and Fluid Flow

View full text Add to dashboard Cite

The core of a Liquid Metal Fast Breeder Reactor (LMFBR) consists of cylindrical fuel rods that are wrapped by a helicoidally-wound wire spacer to enhance mixing and to prevent damage by fretting. It is known that the liquid metal close to the rod is forced to follow the wires, and that liquid metal further away from the rod crosses the wires (called: migratory flow). This work aims at gaining more insight into the physics behind migratory flow and to provide a model for its bending angle. To this purpose, the flow field in a 7-rods, wire-wrapped, hexagonal bundle with water is studied within the Reynolds number range of 4990-16330 by using Particle Image Velocimetry (PIV). Refraction of the light is minimized by using Fluorinated Ethylene Propylene (FEP), which is a refractive index-matching (RIM) material. These measurements confirm that liquid near the rod follows the helicoid path and bends crosswise with respect to the wire further away from the rod. A theoretical model for the bending angle of the flow is derived from the Euler equations and shows that the bending is primarily caused by the pressure gradient field induced by the wire. The model shows a very good correspondence with the experimentally obtained PIV data. These findings improve our understanding of the physics at play in rod bundle flows with wrapped wires and can be of assistance in developing practical correlations for frictional pressure losses and heat transfer in such bundles.

show abstract

Section: Time-averaged Velocity Fieldssupporting

confidence: 58%

Section: Introductionmentioning

confidence: 99%

Understanding migratory flow caused by helicoid wire spacers in rod bundles: An experimental and theoretical study

Bertocchi

Rohde

Kloosterman

2019

International Journal of Heat and Fluid Flow

View full text Add to dashboard Cite

show abstract

“…A comparison of the LES results (see Fig. 7) to the experimental data in an interior sub-channel for a Reynolds number of 19 000 is presented by Goth et al (2018b). They conclude that the shape and magnitude of the mean vertical velocity component is in good agreement with maximum relative errors less than 10% until the subchannel walls are approached.…”

Section: Data Production Programmentioning

confidence: 84%

“…Validation of RANS for the 61-pin bundle described before was performed based on comparison with the LES data presented by Goth et al (2018b). To allow a good quality mesh in LES, it was decided to slightly flatten the wire near the adjacent pin as described in Goth et al (2018b). To avoid any uncertainties in geometric modelling, the RANS model was based on the LES model using exactly the same geometry flattening the wire near the adjacent pin.…”

Section: Numerical Programmentioning

confidence: 99%

See 1 more Smart Citation

Towards validated prediction with RANS CFD of flow and heat transport in a wire-wrap fuel assembly

Roelofs

Uitslag-Doolaard

Dovizio

et al. 2019

Nuclear Engineering and Design

View full text Add to dashboard Cite

Liquid metal fast reactors (LMFRs) are foreseen to play an important role in the future of nuclear energy, thanks to their increased fuel utilization and safety features profiting from the optimal heat transfer performance of the metallic coolants. Accurate thermal-hydraulic analysis of their fuel assemblies, typically employed with wire-wraps as spacers, is recognized as a crucial scientific and engineering contribution to support the deployment of such technology. This challenges the modeling and simulation community. To this aspect, various reference databases (both experimental and numerical) for different wire-wrapped fuel assembly configurations have been created recently and are being used for validation of engineering simulation approaches based on Reynolds Averaged Navier Stokes (RANS) modelling. These databases include: • 7-pin rod bundle: A detailed experiment with Particle Image Velocimetry (PIV) is performed. In order to allow accurate measurements of the flow topology, a matched-index-of-refraction technique was used employing water as working fluid. • 19-pin bundle: A series of experiments is performed covering a wide range of Reynolds and Peclet numbers as well as thermal powers. The experiments use liquid lead-bismuth eutectic as working fluid. The measurements include pressure drop and local temperatures. • 61-pin rod bundle: This large eddy simulation including conjugate heat transfer from the pin cladding to the coolant allows to bridge the gap from small bundles (less than 37 pins) to large bundles (more than 37 pins). In literature, a fundamental different behavior has been observed for small bundles compared to large bundles. • 127-pin bundle: Isothermal experiments using lead-bismuth eutectic characterizing pressure drop are performed on a full scale fuel assembly representative for the MYRRHA reactor. • Infinite pin bundle: This reference quasi-direct numerical simulation profits from periodicity in all directions. It provides a detailed view into the flow field and in addition reveals details of the heat transfer from the rod bundle into the flow. Reference databases aim to serve the nuclear scientific community to validate engineering simulation approaches. The paper will introduce these reference databases, and how they have been used to validate RANS based turbulence modelling approaches within a mainly European context.

show abstract

Turbulent flow and vortex characteristics in a blocked subchannel of a helically wrapped rod bundle

et al. 2019

View full text Add to dashboard Cite

Comparison of experimental and simulation results on interior subchannels of a 61-pin wire-wrapped hexagonal fuel bundle

Cited by 29 publications

References 7 publications

Understanding migratory flow caused by helicoid wire spacers in rod bundles: An experimental and theoretical study

Understanding migratory flow caused by helicoid wire spacers in rod bundles: An experimental and theoretical study

Towards validated prediction with RANS CFD of flow and heat transport in a wire-wrap fuel assembly

Turbulent flow and vortex characteristics in a blocked subchannel of a helically wrapped rod bundle

Contact Info

Product

Resources

About