Work

Experimental study and sub-channel analysis on the transverse mixing of the helical cruciform fuel assembly

Year: 2025

Type: article

Abstract: The helical cruciform fuel (HCF) is characterized as self-mixing and self-supporting, which has promising applications in advanced nuclear power devices. In the presented work, the transverse mixing behaviors of the 4×4 HCF assembly are investigated by tracer method with the Reynolds number scope of 5.90×102 to 1.13×104 . The wire-mesh sensor (WMS) device for the complex-structured bundle channel is designed, which is utilized for the concentration measurement in the range of 0.01352 mol/L to 0.02916 mol/L. The one-way mixing at rod gap type I and two-way mixing at rod gap type II are revealed by the evolution of sub-channel concentration profile. The mixing coefficient of HCF assembly is found to be a geometry depended constant, which is 0.022 for the 4×4 HCF test section of this work. It is confirmed that the transverse mixing of HCF assembly is dominant by flow sweeping rather than the turbulent mixing. The flow sweeping mixing model is developed for the HCF assembly, which involves two sets of momentum equations. This work provides the fundamental experimental data and applicable mixing model for the development of sub-channel code for HCF assembly.

Source: Nuclear Engineering and Technology

DOI: 10.1016/j.net.2025.103587