CFD Simulation the Thermal-Hydraulic Characteristic within Fuel Rod Bundle near Grid Spacers

This paper looks into detailed investigation of thermal-hydraulic characteristics of the flow field in a fuel rod model, especially near the spacer. The area investigate represents a source of information on the velocity flow field, vortex, and on the amount of heat transfer into the coolant all of which are critical for the design and improvement of the fuel rod in nuclear power plants. The flow field investigation uses three-dimensional Computational Fluid Dynamics (CFD) with the Reynolds stresses turbulence model (RSM). The fuel rod model incorporates a vertical annular channel where three different shapes of spacers are used; each spacer shape is addressed individually. These spacers are mutually compared in consideration of heat transfer capabilities between the coolant and the fuel rod model. The results are complemented with the calculated heat transfer coefficient in the location of the spacer and along the stainless-steel pipe.

Authors:

• David Lávicka

Keywords:

• CFD
• fuel rod model
• heat transfer
• spacer

References:

[1] C.C. Liu, "Numerically simulating the thermal-hydraulic characteristics
within the fuel rod bundle using CFD methodology", Nuclear
engineering and design, vol. 240, no┬░10, pp. 3078-3086, May 2010.
[2] B. Kon─ìar, E. Krepper., "CFD simulation of convective flow boiling of
refrigerant in a vertical annulus". Nuclear engineering and design, no. 3,
pp. 693-706, March 2008.
[3] D. Lávička, "A Comparison of Flow Field Characteristics from PIV
Experiment Measurement to Numerical Simulation behind a Spacer in a
Vertical Pipe", Applied and Computational Mechanics, vol. 4, no┬░1,
pp.57-66, Czech republic, July 2010.
[4] ANSYS, Inc., 2011. ANSYS FLUENT Theory Guide, Release 13.0, Nov.
2010.
[5] D. Lávička, "Investigation of temperature field in the annular channel
around the heated wall of the fuel rod", Experiments Fluids Mechanics
2010, vol. 1, pp.338-343, Czech republic, Nov. 2010.