Measurements of turbulent flow in rod bundles with neighboring different spacer grids

Book · Sat Jun 01 04:00:00 EDT 1996

OSTI ID:234280

Yang, S K; Chung, M K ^[1]

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1. Korea Atomic Energy Research Inst., Taejon (Korea, Republic of). Thermal Hydraulics Dept.

In a nuclear fuel design field, the spacer grids in rod bundles are being developed to enhance the thermal mixing efficiency of the coolant flowing through the fuel assembly. However, when the fuel assembly with the newly designed spacer grid is loaded in a reactor, the thermal-hydraulic compatibility between the newly loaded and the existing assemblies is one of the major problems concerned by the nuclear fuel designer. In order to tackle this subject, the authors performed the experiments by a 6 x 6 rod bundle with neighboring different spacer grids with different configurations and resistance. The local hydraulic characteristics in a single phase flow of a 6 x 6 rod bundle with neighboring different spacer grids were measured by using a LDV (Laser Doppler Velocimeter) system. A 6 x 6 rod bundle is formed by two 3 x 6 rod bundles with different spacer grids. The objective of this study in a rod bundle is to investigate the hydraulic interactions between different spacer grids with different configurations and resistance. By using a LDV system, the velocity and turbulent intensity in axial and horizontal directions were measured. Pressure drop measurements were also performed to evaluate the loss coefficient for the spacer grid and the friction factor for rod bundles. Turbulence decay behind the spacer grid behaves as turbulent flow through mesh grids or screens. Correlations for the axial and horizontal turbulent intensity decay were obtained from the resulting data.

• OSTI ID: 234280
• Report Number(s): CONF-960306--; ISBN 0-7918-1226-X
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
DATA COVARIANCES
EXPERIMENTAL DATA
FRICTION FACTOR
FUEL ELEMENT CLUSTERS
LASER DOPPLER ANEMOMETERS
SPACERS
TURBULENT FLOW